blocks|key|5336452|text|您可以使用getActivity()，它返回与fragment关联的活动。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|5336453|该活动是一个context+(因为Activity扩展了Context__)。|5336454|entityMap|0|LINK|mutability|MUTABLE|url|http://developer.android.com/reference/android/app/Fragment.html#getActivity%2528%2529^0|5|D|N|8|5|D|0|0|6|7|H|8|S|7|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]|$9|S|A|T|B|C]]|D|@$9|U|A|V|1|W]]|E|$]]|$1|F|3|G|5|6|7|X|8|@$9|Y|A|Z|B|C]|$9|10|A|11|B|C]|$9|12|A|13|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|I|$J|$5|K|L|M|E|$N|O]]]]

You can use <a href="http://developer.android.com/reference/android/app/Fragment.html#getActivity%28%29" rel="noreferrer"><code>getActivity()</code></a>, which returns the activity associated with a <code>fragment</code>. 
The activity is a <code>context</code> (since <code>Activity</code> extends <code>Context</code>).

blocks|key|5051470|text|要按照上面的答案操作，您可以覆盖fragment的onAttach方法：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|5051471|public+static+class+DummySectionFragment+extends+Fragment{
...
++++@Override
++++public+void+onAttach(Activity+activity)+{
++++++++super.onAttach(activity);
++++++++DBHelper+=+new+DatabaseHelper(activity);
++++}
}|code-block|syntax|javascript|5051472|entityMap^0|P|8|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

To do as the answer above, you can override the <code>onAttach</code> method of fragment:

<pre><code>public static class DummySectionFragment extends Fragment{
...
 @Override
 public void onAttach(Activity activity) {
 super.onAttach(activity);
 DBHelper = new DatabaseHelper(activity);
 }
}
</code></pre>

blocks|key|5051499|text|获取我找到的片段上下文的最简单、最精确的方法是在调用onCreateView方法时直接从ViewGroup获取它，至少在这里，您肯定不会为getActivity()获取null|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|5051500|public+class+Animal+extends+Fragment+{+
++Context+thiscontext;
++@Override
++public+View+onCreateView(LayoutInflater+inflater,+ViewGroup+container,+Bundle+savedInstanceState)
++{
++++thiscontext+=+container.getContext();|code-block|syntax|javascript|5051501|entityMap^0|Q|C|18|9|1X|D|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|U|8|@]|D|@]|E|$]]]|L|$]]

The easiest and most precise way to get the context of the fragment that I found is to get it directly from the <code>ViewGroup</code> when you call <code>onCreateView</code> method at least here you are sure not to get null for <code>getActivity()</code>:

<pre><code>public class Animal extends Fragment { 
 Context thiscontext;
 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
 {
 thiscontext = container.getContext();
</code></pre>

blocks|key|948003|text|始终使用getActivity()方法来获取附加活动的上下文，但请始终记住一件事:片段稍微不稳定，getActivity有时会返回null，因此，在通过getActivity()获取上下文之前，请始终检查fragment的isAdded()方法。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|948004|entityMap|0|LINK|mutability|MUTABLE|url|http://developer.android.com/reference/android/app/Fragment.html#getActivity%2528%2529|1|http://developer.android.com/reference/android/app/Fragment.html#isAdded()^0|1D|B|24|D|4|D|0|33|9|1|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]|$9|S|A|T|B|C]]|D|@$9|U|A|V|1|W]|$9|X|A|Y|1|Z]]|E|$]]|$1|F|3|-4|5|6|7|10|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]|N|$5|I|J|K|E|$L|O]]]]

Always use the <a href="http://developer.android.com/reference/android/app/Fragment.html#getActivity%28%29">getActivity()</a> method to get the context of your attached activity, but always remember one thing: Fragments are slightly unstable and <code>getActivity</code> returns null some times, so for that, always check the <a href="http://developer.android.com/reference/android/app/Fragment.html#isAdded()">isAdded()</a> method of fragment before getting context by <code>getActivity()</code>.

blocks|key|3438845|text|之前，我使用onAttach+(Activity+activity)在Fragment中获取context|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3438846|3438847|问题|blockquote|3438848|3438849|3438850|方法在API级别23中已弃用。|3438851|3438852|解决方案|3438853|3438854|3438855|现在，我们可以使用来获取Fragment中的上下文|3438856|3438857|+onAttach+(Context+context)|BOLD|3438858|3438859|3438860|当片段首次附加到其context时调用|3438861|。在此之后将调用onCreate(Bundle)。|unordered-list-item|3438862|3438863|3438864|文档|3438865|3438866|3438867|/**
+*+Called+when+a+fragment+is+first+attached+to+its+context.
+*+{@link+#onCreate(Bundle)}+will+be+called+after+this.
+*/
@CallSuper
public+void+onAttach(Context+context)+{
++++mCalled+=+true;
++++final+Activity+hostActivity+=+mHost+==+null+?+null+:+mHost.getActivity();
++++if+(hostActivity+!=+null)+{
++++++++mCalled+=+false;
++++++++onAttach(hostActivity);
++++}
}|code-block|syntax|javascript|3438868|示例代码|3438869|public+class+FirstFragment+extends+Fragment+{


++++private+Context+mContext;
++++public+FirstFragment()+{
++++++++//+Required+empty+public+constructor
++++}

++++@Override
++++public+void+onAttach(Context+context)+{
++++++++super.onAttach(context);
++++++++mContext=context;
++++}

++++@Override
++++public+View+onCreateView(LayoutInflater+inflater,+ViewGroup+container,
+++++++++++++++++++++++++++++Bundle+savedInstanceState)+{
++++++++View+rooView=inflater.inflate(R.layout.fragment_first,+container,+false);

++++++++Toast.makeText(mContext,+"THIS+IS+SAMPLE+TOAST",+Toast.LENGTH_SHORT).show();
++++++++//+Inflate+the+layout+for+this+fragment
++++++++return+rooView;
++++}

}|3438870|备注|3438871|我们也可以使用getActivity()在Fragments中获取context，但如果您的fragment当前未附加到父activity，则getActivity()可以返回null。|3438872|entityMap^0|6|S|Z|8|1A|7|0|0|0|0|0|0|0|0|0|0|C|8|0|0|1|Q|1|Q|0|0|0|9|7|0|8|G|0|0|0|0|0|0|0|0|4|0|0|0|7|D|7|D|L|9|X|7|1A|8|1P|8|1Z|D|2G|4|0^^$0|@$1|2|3|4|5|6|7|1Q|8|@$9|1R|A|1S|B|C]|$9|1T|A|1U|B|C]|$9|1V|A|1W|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|1X|8|@]|D|@]|E|$]]|$1|G|3|H|5|I|7|1Y|8|@]|D|@]|E|$]]|$1|J|3|-4|5|6|7|1Z|8|@]|D|@]|E|$]]|$1|K|3|-4|5|6|7|20|8|@]|D|@]|E|$]]|$1|L|3|M|5|6|7|21|8|@]|D|@]|E|$]]|$1|N|3|-4|5|6|7|22|8|@]|D|@]|E|$]]|$1|O|3|P|5|I|7|23|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|24|8|@]|D|@]|E|$]]|$1|R|3|-4|5|6|7|25|8|@]|D|@]|E|$]]|$1|S|3|T|5|6|7|26|8|@$9|27|A|28|B|C]]|D|@]|E|$]]|$1|U|3|-4|5|6|7|29|8|@]|D|@]|E|$]]|$1|V|3|W|5|I|7|2A|8|@$9|2B|A|2C|B|X]|$9|2D|A|2E|B|C]]|D|@]|E|$]]|$1|Y|3|-4|5|6|7|2F|8|@]|D|@]|E|$]]|$1|Z|3|-4|5|6|7|2G|8|@]|D|@]|E|$]]|$1|10|3|11|5|6|7|2H|8|@$9|2I|A|2J|B|C]]|D|@]|E|$]]|$1|12|3|13|5|14|7|2K|8|@$9|2L|A|2M|B|C]]|D|@]|E|$]]|$1|15|3|-4|5|6|7|2N|8|@]|D|@]|E|$]]|$1|16|3|-4|5|6|7|2O|8|@]|D|@]|E|$]]|$1|17|3|18|5|I|7|2P|8|@]|D|@]|E|$]]|$1|19|3|-4|5|6|7|2Q|8|@]|D|@]|E|$]]|$1|1A|3|-4|5|6|7|2R|8|@]|D|@]|E|$]]|$1|1B|3|1C|5|1D|7|2S|8|@]|D|@]|E|$1E|1F]]|$1|1G|3|1H|5|6|7|2T|8|@$9|2U|A|2V|B|X]]|D|@]|E|$]]|$1|1I|3|1J|5|1D|7|2W|8|@]|D|@]|E|$1E|1F]]|$1|1K|3|1L|5|6|7|2X|8|@]|D|@]|E|$]]|$1|1M|3|1N|5|6|7|2Y|8|@$9|2Z|A|30|B|X]|$9|31|A|32|B|C]|$9|33|A|34|B|C]|$9|35|A|36|B|C]|$9|37|A|38|B|C]|$9|39|A|3A|B|C]|$9|3B|A|3C|B|C]|$9|3D|A|3E|B|C]]|D|@]|E|$]]|$1|1O|3|-4|5|6|7|3F|8|@]|D|@]|E|$]]]|1P|$]]

Previously I'm using <code>onAttach (Activity activity)</code> to get <code>context</code> in <code>Fragment</code>

<blockquote>
 Problem 
</blockquote>

The <a href="https://developer.android.com/reference/android/app/Fragment.html#onAttach(android.app.Activity)" rel="noreferrer"><code>onAttach (Activity activity)</code></a> method was deprecated in API level 23.

<blockquote>
 Solution 
</blockquote>

Now to get context in <code>Fragment</code> we can use <a href="https://developer.android.com/reference/android/app/Fragment.html#onAttach(android.content.Context)" rel="noreferrer"><code>onAttach (Context context)</code></a>

<blockquote>
 <code>onAttach (Context context)</code>
</blockquote>

<ul>
<li>Called when a fragment is first attached to its <code>context</code>. <code>onCreate(Bundle)</code> will be called after this. </li>
</ul>

<blockquote>
 Documentation 
</blockquote>

<pre><code>/**
 * Called when a fragment is first attached to its context.
 * {@link #onCreate(Bundle)} will be called after this.
 */
@CallSuper
public void onAttach(Context context) {
 mCalled = true;
 final Activity hostActivity = mHost == null ? null : mHost.getActivity();
 if (hostActivity != null) {
 mCalled = false;
 onAttach(hostActivity);
 }
}
</code></pre>

SAMPLE CODE

<pre><code>public class FirstFragment extends Fragment {


 private Context mContext;
 public FirstFragment() {
 // Required empty public constructor
 }

 @Override
 public void onAttach(Context context) {
 super.onAttach(context);
 mContext=context;
 }

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
 Bundle savedInstanceState) {
 View rooView=inflater.inflate(R.layout.fragment_first, container, false);

 Toast.makeText(mContext, "THIS IS SAMPLE TOAST", Toast.LENGTH_SHORT).show();
 // Inflate the layout for this fragment
 return rooView;
 }

}
</code></pre>

<h2>NOTE</h2>

We can also use <code>getActivity()</code> to get <code>context</code> in <code>Fragments</code>
but <code>getActivity()</code> can return <code>null</code> if the your <code>fragment</code> is not currently attached to a parent <code>activity</code>,

blocks|key|3438348|text|@Override
public+void+onAttach(Activity+activity)+{
++++//+TODO+Auto-generated+method+stub
++++super.onAttach(activity);
++++context=activity;
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|3438349|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>@Override
public void onAttach(Activity activity) {
 // TODO Auto-generated method stub
 super.onAttach(activity);
 context=activity;
}
</code></pre>

blocks|key|5337290|text|requireContext()方法是最简单的选择|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5337291|requireContext()|code-block|syntax|javascript|5337292|示例|5337293|MyDatabase(requireContext())|5337294|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

requireContext() method is the simplest option

<pre><code>requireContext()
</code></pre>

Example

<pre><code>MyDatabase(requireContext())
</code></pre>

blocks|key|5051747|text|当覆盖onCreateView时，您还可以从inflater参数获取上下文。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|5051748|public+static+class+MyFragment+extends+Fragment+{
++++@Override
++++public+View+onCreateView(LayoutInflater+inflater,+ViewGroup+container,
+++++++++++++++++++++++++++++++++Bundle+savedInstanceState)+{
++++++++/*+...+*/
++++++++Context+context+=+inflater.getContext();
++++++++/*+...+*/
++++}
}|code-block|syntax|javascript|5051749|entityMap^0|3|C|M|8|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

You could also get the context from the <code>inflater</code> parameter, when overriding <code>onCreateView</code>.

<pre><code>public static class MyFragment extends Fragment {
 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
 Bundle savedInstanceState) {
 /* ... */
 Context context = inflater.getContext();
 /* ... */
 }
}
</code></pre>

blocks|key|951450|text|正确的方法是使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|951451|requireContext()|code-block|syntax|javascript|951452|下面的例子|951453|ContextCompat.getColor(requireContext(),+R.color.colorAccent),|951454|951455|原始答案(请参阅答案修订)|951456|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|Q|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|R|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|S|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|T|8|@]|9|@]|A|$]]|$1|L|3|M|5|6|7|U|8|@]|9|@]|A|$]]|$1|N|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|O|$]]

The correct way is to use
<pre><code>requireContext()
</code></pre>
and the example
<pre><code>ContextCompat.getColor(requireContext(), R.color.colorAccent),
</code></pre>
<hr>
Original Answer (see answer revisions)

blocks|key|5051581|text|另一种替代方法是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5051582|您可以使用以下命令获取上下文：|5051583|getActivity().getApplicationContext();|code-block|syntax|javascript|5051584|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Another alternative approach is:

You can get the context using:

<pre><code>getActivity().getApplicationContext();
</code></pre>

blocks|key|5336697|text|要获得片段中的上下文，可以使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5336698|public+Database()
{
++++this.context+=+getActivity();
++++DBHelper+=+new+DatabaseHelper(this.context);
}|code-block|syntax|javascript|5336699|5336700|要小心，要使用getActivity()获取与片段相关联的Activity，您可以使用它，但不建议这样做会导致内存泄漏。|unordered-list-item|offset|length|style|CODE|5336701|5336702|我认为更好的方法应该是从onAttach()方法中获取Activity：|5336703|@Override
public+void+onAttach(Activity+activity)+{
++++super.onAttach(activity);
++++context+=+activity;
}|5336704|entityMap^0|0|0|0|7|D|T|8|0|0|C|A|R|8|0|0^^$0|@$1|2|3|4|5|6|7|V|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|W|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|X|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|Y|8|@$K|Z|L|10|M|N]|$K|11|L|12|M|N]]|9|@]|A|$]]|$1|O|3|-4|5|6|7|13|8|@]|9|@]|A|$]]|$1|P|3|Q|5|6|7|14|8|@$K|15|L|16|M|N]|$K|17|L|18|M|N]]|9|@]|A|$]]|$1|R|3|S|5|D|7|19|8|@]|9|@]|A|$E|F]]|$1|T|3|-4|5|6|7|1A|8|@]|9|@]|A|$]]]|U|$]]

to get the context inside the Fragment will be possible using <a href="http://developer.android.com/intl/es/reference/android/app/Fragment.html#getActivity()" rel="nofollow"><code>getActivity()</code></a> :

<pre><code>public Database()
{
 this.context = getActivity();
 DBHelper = new DatabaseHelper(this.context);
}
</code></pre>

<ul>
<li>Be careful, to get the <code>Activity</code> associated with the fragment using <code>getActivity()</code>, you can use it but is not recommended it will cause memory leaks.</li>
</ul>

I think a better aproach must be getting the <code>Activity</code> from the <code>onAttach()</code> method:

<pre><code>@Override
public void onAttach(Activity activity) {
 super.onAttach(activity);
 context = activity;
}
</code></pre>

blocks|key|951185|text|getContext()是在API23中发布的。在代码中的任何地方用getActivity()替换它。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|951186|看看它是否修复了这个错误。尝试使用介于目标和最低API级别之间的方法，否则将出现此错误。|951187|entityMap^0|0|C|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|M|8|@]|D|@]|E|$]]|$1|H|3|-4|5|6|7|N|8|@]|D|@]|E|$]]]|I|$]]

<code>getContext()</code> came in API 23. Replace it with getActivity() everywhere in the code.

See if it fixes the error. Try to use methods which are in between the target and minimun API level, else this error will come in place.

blocks|key|5336890|text|由于API23级有getContext()，但是如果你想支持老版本，你可以使用getActivity().getApplicationContext()，而我仍然推荐使用Fragment的支持版本，即android.support.v4.app.Fragment。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|5336891|entityMap^0|9|C|13|11|2D|8|2S|V|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|G|$]]

Since API level 23 there is <code>getContext()</code> but if you want to support older versions you can use <code>getActivity().getApplicationContext()</code> while I still recommend using the support version of <code>Fragment</code> which is <code>android.support.v4.app.Fragment</code>.

blocks|key|948182|text|对于Kotlin，您可以直接在片段中使用context。但在某些情况下，您会发现如下错误|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|948183|948184|类型不匹配:推断的类型是上下文？但上下文是预期的|blockquote|948185|948186|948187|为此，您可以这样做|948188|val+ctx+=+context+?:+return
textViewABC.setTextColor(ContextCompat.getColor(ctx,+android.R.color.black))|code-block|syntax|javascript|948189|entityMap^0|K|7|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|X|8|@]|D|@]|E|$]]|$1|G|3|H|5|I|7|Y|8|@]|D|@]|E|$]]|$1|J|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]|$1|K|3|-4|5|6|7|10|8|@]|D|@]|E|$]]|$1|L|3|M|5|6|7|11|8|@]|D|@]|E|$]]|$1|N|3|O|5|P|7|12|8|@]|D|@]|E|$Q|R]]|$1|S|3|-4|5|6|7|13|8|@]|D|@]|E|$]]]|T|$]]

For Kotlin you can use <code>context</code> directly in fragments. But in some cased you will find an error like

<blockquote>
 Type mismatch: inferred type is Context? but Context was expected
</blockquote>

for that you can do this

<pre><code>val ctx = context ?: return
textViewABC.setTextColor(ContextCompat.getColor(ctx, android.R.color.black))
</code></pre>

blocks|key|5051605|text|getActivity()是Context的子级，因此它应该适用于您|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|5051606|entityMap^0|0|D|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

<code>getActivity()</code> is a child of Context so that should work for you

blocks|key|3438672|text|您有不同的选项：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3438673|如果您的minSDK+<=+21，则可以使用getActivity()，因为this+is+a+Context.|offset|length|style|CODE|3438674|If+minSDK+<=+is+getActivity()，那么您可以使用getContext().|unordered-list-item|3438675|3438676|如果您不需要支持旧版本，那么就使用getContext()。|3438677|entityMap^0|0|M|D|1C|7|0|G|D|11|C|0|0|H|C|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Q|8|@$D|R|E|S|F|G]|$D|T|E|U|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|V|8|@$D|W|E|X|F|G]|$D|Y|E|Z|F|G]]|9|@]|A|$]]|$1|K|3|-4|5|6|7|10|8|@]|9|@]|A|$]]|$1|L|3|M|5|6|7|11|8|@$D|12|E|13|F|G]]|9|@]|A|$]]|$1|N|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|O|$]]

You have different options:

<ul>
<li>If your minSDK &lt;= 21, then you can use <code>getActivity()</code>, since this is a <code>Context</code>.</li>
<li>If your minSDK is >=23, then you can use <code>getContext()</code>.</li>
</ul>

If you don't need to support old versions then go with <code>getContext()</code>.

blocks|key|3438697|text|使用支持库中的片段-|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|3438698|android.support.v4.app.Fragment|code-block|syntax|javascript|3438699|然后重写|3438700|void+onAttach+(Context+context)+{
++this.context+=+context;
}|3438701|这样，您就可以确保context始终是一个非空值。|3438702|entityMap^0|2|3|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|W|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|Y|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|R|$]]

Use fragments from Support Library - 

<pre><code>android.support.v4.app.Fragment
</code></pre>

and then override

<pre><code>void onAttach (Context context) {
 this.context = context;
}
</code></pre>

This way you can be sure that context will always be a non-null value.

blocks|key|5337148|text|在kotlin中，只需使用activity而不是getActivity()|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|CODE|entityRanges|data|5337149|entityMap^0|1|6|D|8|O|D|0^^$0|@$1|2|3|4|5|6|7|I|8|@$9|J|A|K|B|C]|$9|L|A|M|B|D]|$9|N|A|O|B|D]]|E|@]|F|$]]|$1|G|3|-4|5|6|7|P|8|@]|E|@]|F|$]]]|H|$]]

In kotlin just use <code>activity</code> instead of <code>getActivity()</code>

blocks|key|3438941|text|您可以使用getActivity()方法获取上下文，也可以使用getContext()方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3438942|+View+root+=+inflater.inflate(R.layout.fragment_slideshow,+container,+false);
++++Context+c+=+root.getContext();|code-block|syntax|javascript|3438943|我希望它能有所帮助！|3438944|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

You can use getActivity() method to get context or 
You can use getContext() method .

<pre><code> View root = inflater.inflate(R.layout.fragment_slideshow, container, false);
 Context c = root.getContext();
</code></pre>

I hope it helps!

blocks|key|5337368|text|在片段中获取上下文的安全方法|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5337369|if(isAdded){
requireActivit();//this+is+your+context
}|code-block|syntax|javascript|5337370|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

safe way to get context in fragment
<pre><code>if(isAdded){
requireActivit();//this is your context
}
</code></pre>

blocks|key|5336749|text|简单的方法是使用getActivity()。但我认为在这里使用getActivity()方法获取上下文的主要混乱之处在于空指针异常。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|5336750|为此，首先检查isAdded()方法，该方法将确定是否添加了它，然后我们可以使用getActivity()来获取活动的上下文。|5336751|entityMap^0|8|D|V|D|0|7|9|14|D|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|I|$]]

The simple way is to use <code>getActivity()</code>. But I think the major confusion of using the <code>getActivity()</code> method to get the context here is a null pointer exception. 

For this, first check with the <code>isAdded()</code> method which will determine whether it's added or not, and then we can use the <code>getActivity()</code> to get the context of Activity.

blocks|key|5336842|text|理想情况下，您不需要使用全局变量。片段有不同的通知，其中之一是onActivityCreated。您可以在片段的这个生命周期事件中获取活动的实例。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5336843|然后:您可以根据需要取消对片段的引用，以获取活动、上下文或应用程序上下文：|5336844|this.getActivity()将提供活动的句柄，this.getContext()将为您提供上下文的句柄，this.getActivity().getApplicationContext()将为您提供应用程序上下文的句柄。在将应用程序上下文传递给数据库时，最好使用应用程序上下文。|offset|length|style|CODE|5336845|entityMap^0|0|0|0|I|R|H|1K|16|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|N|8|@$F|O|G|P|H|I]|$F|Q|G|R|H|I]|$F|S|G|T|H|I]]|9|@]|A|$]]|$1|J|3|-4|5|6|7|U|8|@]|9|@]|A|$]]]|K|$]]

Ideally, you should not need to use globals. The fragment has different notifications, one of them being onActivityCreated. You can get the instance of the activity in this lifecycle event of the fragment.

Then: you can dereference the fragment to get activity, context or applicationcontext as you desire:

<code>this.getActivity()</code> will give you the handle to the activity
<code>this.getContext()</code> will give you a handle to the context
<code>this.getActivity().getApplicationContext()</code> will give you the handle to the application context. You should preferably use the application context when passing it on to the db.

blocks|key|951261|text|您可以调用getActivity()或|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|951262|public+void+onAttach(Context+context)+{
++++super.onAttach(context);
++++this.activity+=+(CashActivity)+context;
++++this.money+=+this.activity.money;
}|code-block|syntax|javascript|951263|entityMap^0|5|D|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

You can call <code>getActivity()</code> or,

<pre><code>public void onAttach(Context context) {
 super.onAttach(context);
 this.activity = (CashActivity) context;
 this.money = this.activity.money;
}
</code></pre>

blocks|key|3438750|text|我想你可以用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3438751|public+static+class+MyFragment+extends+Fragment+{
++@Override
++public+View+onCreateView(LayoutInflater+inflater,+ViewGroup+container,
+++++++++++++++++++++++++++++Bundle+savedInstanceState)+{

++++++Context+context+=+getActivity.getContext();

++}
}|code-block|syntax|javascript|3438752|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I think you can use

<pre><code>public static class MyFragment extends Fragment {
 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
 Bundle savedInstanceState) {

 Context context = getActivity.getContext();

 }
}
</code></pre>

blocks|key|951346|text|public+class+MenuFragment+extends+Fragment+implements+View.OnClickListener+{
++++private+Context+mContext;
++++@Override
++++public+View+onCreateView(LayoutInflater+inflater,+ViewGroup+container,+Bundle+savedInstanceState)+{
++++++++FragmentMenuBinding+binding=FragmentMenuBinding.inflate(inflater,container,false);
++++++++View+view=binding.getRoot();
++++++++mContext=view.getContext();
++++++++return+view;
++++}
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|951347|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>public class MenuFragment extends Fragment implements View.OnClickListener {
 private Context mContext;
 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
 FragmentMenuBinding binding=FragmentMenuBinding.inflate(inflater,container,false);
 View view=binding.getRoot();
 mContext=view.getContext();
 return view;
 }
}
</code></pre>

blocks|key|3438794|text|我需要使用arrayAdapter+IN+fragment的上下文，当我使用getActivity时发生错误，但当我用getContext替换它时，它对我有效|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|3438795|listView+LV=getView().findViewById(R.id.listOFsensors);
LV.setAdapter(new+ArrayAdapter<String>(getContext(),android.R.layout.simple_list_item_1+,listSensorType));|code-block|syntax|javascript|3438796|entityMap^0|12|B|1N|A|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

I need context for using arrayAdapter IN fragment, when I was using getActivity error occurs but when i replace it with getContext it works for me

<pre><code>listView LV=getView().findViewById(R.id.listOFsensors);
LV.setAdapter(new ArrayAdapter&lt;String&gt;(getContext(),android.R.layout.simple_list_item_1 ,listSensorType));
</code></pre>

blocks|key|3438898|text|关于你的片段|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3438899|((Name_of_your_Activity)+getActivity()).helper|code-block|syntax|javascript|3438900|论活动|3438901|DbHelper+helper+=+new+DbHelper(this);|3438902|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

On you fragment 

<pre><code>((Name_of_your_Activity) getActivity()).helper
</code></pre>

On Activity

<pre><code>DbHelper helper = new DbHelper(this);
</code></pre>

blocks|key|5337200|text|kotlin样本的内部片段可以帮助某些人|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5337201|textViewStatus.setTextColor(ContextCompat.getColor(context!!,+R.color.red))|code-block|syntax|javascript|5337202|如果你使用数据绑定；|5337203|bindingView.textViewStatus.setTextColor(ContextCompat.getColor(context!!,+R.color.red))|5337204|在onCreateView中初始化bindingView的位置如下所示|offset|length|style|BOLD|5337205|private+lateinit+var+bindingView:+FragmentBookingHistoryDetailBinding

bindingView+=+DataBindingUtil.inflate(inflater,+R.layout.your_layout_xml,+container,+false)|5337206|entityMap^0|0|0|0|0|1|C|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|Y|8|@$M|Z|N|10|O|P]]|9|@]|A|$]]|$1|Q|3|R|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

Inside fragment for kotlin sample would help someone

<pre><code>textViewStatus.setTextColor(ContextCompat.getColor(context!!, R.color.red))
</code></pre>

if you use databinding;

<pre><code>bindingView.textViewStatus.setTextColor(ContextCompat.getColor(context!!, R.color.red))
</code></pre>

Where bindingView is initialized in onCreateView like this

<pre><code>private lateinit var bindingView: FragmentBookingHistoryDetailBinding

bindingView = DataBindingUtil.inflate(inflater, R.layout.your_layout_xml, container, false)
</code></pre>

blocks|key|3439180|text|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3439181|​|ordered-list-item|3439182|3439183|您可以使用getActivity()，它返回与片段相关联的活动。活动是一个上下文(因为活动扩展了上下文)。|3439184|注意:如果在相应片段的onAttach之前调用getActivity()，它可能会返回null。|3439185|2.or|3439186|获取我找到的片段上下文的最简单、最精确的方法是在调用onCreateView方法时直接从ViewGroup获取它，至少在这里，您肯定不会为getActivity()获取null：|3439187|public+class+Animal+extends+Fragment+{+
Context+thiscontext;
@Override
public+View+onCreateView(LayoutInflater+inflater,+
ViewGroup+container,+Bundle+savedInstanceState)
{
thiscontext+=+container.getContext();
//...
//...
//...
}|code-block|syntax|javascript|3439188|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|-4|4|5|6|T|7|@]|8|@]|9|$]]|$1|A|3|B|4|C|6|U|7|@]|8|@]|9|$]]|$1|D|3|-4|4|5|6|V|7|@]|8|@]|9|$]]|$1|E|3|F|4|5|6|W|7|@]|8|@]|9|$]]|$1|G|3|H|4|5|6|X|7|@]|8|@]|9|$]]|$1|I|3|J|4|5|6|Y|7|@]|8|@]|9|$]]|$1|K|3|L|4|5|6|Z|7|@]|8|@]|9|$]]|$1|M|3|N|4|O|6|10|7|@]|8|@]|9|$P|Q]]|$1|R|3|-4|4|5|6|11|7|@]|8|@]|9|$]]]|S|$]]

<ol>
<li></li>
</ol>
You can use getActivity(), which returns the activity associated with a fragment.
The activity is a context (since Activity extends Context).
be careful: getActivity() can return null if it is called before onAttach of the respective fragment.
2.or
The easiest and most precise way to get the context of the fragment that I found is to get it directly from the ViewGroup when you call onCreateView method at least here you are sure not to get null for getActivity():
<pre><code>public class Animal extends Fragment { 
Context thiscontext;
@Override
public View onCreateView(LayoutInflater inflater, 
ViewGroup container, Bundle savedInstanceState)
{
thiscontext = container.getContext();
//...
//...
//...
}
</code></pre>

How can I get the context in a fragment?

I need to use my database whose constructor takes in the context, but <code>getApplicationContext()</code> and <code>FragmentClass.this</code> don't work so what can I do?

Database constructor

<pre><code>public Database(Context ctx)
{
 this.context = ctx;
 DBHelper = new DatabaseHelper(context);
}
</code></pre>

Using context in a fragment

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文章&问答评论现已支持表情

如何获取片段中的上下文？我需要使用我的数据库，它的构造函数接受上下文，但是getApplicationContext()和FragmentClass.this不能工作，我该怎么办？数据库构造函数public Database(Context ctx){    this.context = ctx;    DBHelper = new DatabaseHelper(context);}

问在片段中使用上下文
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回答 29

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