blocks|key|1349936|text|来制作CustomAutoCompleteTextView。1.重写setThreshold、enoughToFilter、onFocusChanged方法|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1349937|public+class+CustomAutoCompleteTextView++extends+AutoCompleteTextView+{+

++++private+int+myThreshold;+

++++public+CustomAutoCompleteTextView++(Context+context)+{+
++++++++super(context);+
++++}+

++++public+CustomAutoCompleteTextView++(Context+context,+AttributeSet+attrs,+int+defStyle)+{+
++++++++super(context,+attrs,+defStyle);+
++++}+

++++public+CustomAutoCompleteTextView++(Context+context,+AttributeSet+attrs)+{+
++++++++super(context,+attrs);+
++++}+
+++++//set+threshold+0.
++++public+void+setThreshold(int+threshold)+{+
++++++++if+(threshold+<+0)+{+
++++++++++++threshold+=+0;+
++++++++}+
++++++++myThreshold+=+threshold;+
++++}+
++++//if+threshold+++is+0+than+return+true
++++public+boolean+enoughToFilter()+{+
+++++++++return+true;
++++++++}+
++++//invoke+on+focus+
++++protected+void+onFocusChanged(boolean+focused,+int+direction,
++++++++++++Rect+previouslyFocusedRect)+{
++++++++++++++++++++//skip+space+and+backspace+
++++++++super.performFiltering("",+67);
++++++++//+TODO+Auto-generated+method+stub
++++++++super.onFocusChanged(focused,+direction,+previouslyFocusedRect);

++++}

++++protected+void+performFiltering(CharSequence+text,+int+keyCode)+{
++++++++//+TODO+Auto-generated+method+stub
++++++++super.performFiltering(text,+keyCode);
++++}

++++public+int+getThreshold()+{+
++++++++return+myThreshold;+
++++}+
}|code-block|syntax|javascript|1349938|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|$]]

To make CustomAutoCompleteTextView.
1. override setThreshold,enoughToFilter,onFocusChanged method

<pre><code>public class CustomAutoCompleteTextView extends AutoCompleteTextView { 

 private int myThreshold; 

 public CustomAutoCompleteTextView (Context context) { 
 super(context); 
 } 

 public CustomAutoCompleteTextView (Context context, AttributeSet attrs, int defStyle) { 
 super(context, attrs, defStyle); 
 } 

 public CustomAutoCompleteTextView (Context context, AttributeSet attrs) { 
 super(context, attrs); 
 } 
 //set threshold 0.
 public void setThreshold(int threshold) { 
 if (threshold &lt; 0) { 
 threshold = 0; 
 } 
 myThreshold = threshold; 
 } 
 //if threshold is 0 than return true
 public boolean enoughToFilter() { 
 return true;
 } 
 //invoke on focus 
 protected void onFocusChanged(boolean focused, int direction,
 Rect previouslyFocusedRect) {
 //skip space and backspace 
 super.performFiltering("", 67);
 // TODO Auto-generated method stub
 super.onFocusChanged(focused, direction, previouslyFocusedRect);

 }

 protected void performFiltering(CharSequence text, int keyCode) {
 // TODO Auto-generated method stub
 super.performFiltering(text, keyCode);
 }

 public int getThreshold() { 
 return myThreshold; 
 } 
}
</code></pre>

blocks|key|1134630|text|您可以使用onFocusChangeListener；|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1134631|TCKimlikNo.setOnFocusChangeListener(new+OnFocusChangeListener()+{

++++++++@Override
++++++++public+void+onFocusChange(View+v,+boolean+hasFocus)+{
++++++++++++if+(hasFocus)+{
++++++++++++++++TCKimlikNo.showDropDown();

++++++++++++}

++++++++}
++++});|code-block|syntax|javascript|1134632|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|$]]

You can use onFocusChangeListener;

<pre><code>TCKimlikNo.setOnFocusChangeListener(new OnFocusChangeListener() {

 @Override
 public void onFocusChange(View v, boolean hasFocus) {
 if (hasFocus) {
 TCKimlikNo.showDropDown();

 }

 }
 });
</code></pre>

blocks|key|1134659|text|最简单的方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1134660|只需使用setOnTouchListener和showDropDown()|1134661|AutoCompleteTextView+text;
.....
.....
text.setOnTouchListener(new+View.OnTouchListener(){
+++@Override
+++public+boolean+onTouch(View+v,+MotionEvent+event){
++++++text.showDropDown();
++++++return+false;
+++}
});|code-block|syntax|javascript|1134662|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|$]]

Easiest way:

Just use setOnTouchListener and showDropDown()

<pre><code>AutoCompleteTextView text;
.....
.....
text.setOnTouchListener(new View.OnTouchListener(){
 @Override
 public boolean onTouch(View v, MotionEvent event){
 text.showDropDown();
 return false;
 }
});
</code></pre>

blocks|key|1350062|text|Destil上面的答案几乎是有效的，但有一个微妙的错误。当用户第一次将焦点放到字段时，它可以工作，但是，如果他们离开然后返回到字段，它将不会显示下拉列表，因为mPopupCanBeUpdated的值在隐藏时仍为false。修复方法是将onFocusChanged方法更改为：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1350063|@Override
protected+void+onFocusChanged(boolean+focused,+int+direction,
++++++++Rect+previouslyFocusedRect)+{
++++super.onFocusChanged(focused,+direction,+previouslyFocusedRect);
++++if+(focused)+{
++++++++if+(getText().toString().length()+==+0)+{
++++++++++++//+We+want+to+trigger+the+drop+down,+replace+the+text.
++++++++++++setText("");
++++++++}
++++}
}|code-block|syntax|javascript|1350064|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|$]]

Destil's answer above almost works, but has one subtle bug. When the user first gives focus to the field it works, however if they leave and then return to the field it will not show the drop down because the value of mPopupCanBeUpdated will still be false from when it was hidden. The fix is to change the onFocusChanged method to:

<pre><code>@Override
protected void onFocusChanged(boolean focused, int direction,
 Rect previouslyFocusedRect) {
 super.onFocusChanged(focused, direction, previouslyFocusedRect);
 if (focused) {
 if (getText().toString().length() == 0) {
 // We want to trigger the drop down, replace the text.
 setText("");
 }
 }
}
</code></pre>

blocks|key|1350158|text|适配器最初不执行过滤。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1350159|如果不执行过滤，则下拉列表为空。|1350160|因此，您可能必须在开始时进行过滤。|1350161|为此，您可以在完成添加条目后调用filter()：|offset|length|style|CODE|1350162|adapter.add("a1");
adapter.add("a2");
adapter.add("a3");
adapter.getFilter().filter(null);|code-block|syntax|javascript|1350163|entityMap^0|0|0|0|G|8|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|U|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|V|8|@$H|W|I|X|J|K]]|9|@]|A|$]]|$1|L|3|M|5|N|7|Y|8|@]|9|@]|A|$O|P]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

The adapter does not perform filtering initially. 
When the filtering is not performed, the dropdown list is empty. 
so you might have to get the filtering going initially. 

To do so, you can invoke <code>filter()</code> after you finish adding the entries: 

<pre><code>adapter.add("a1");
adapter.add("a2");
adapter.add("a3");
adapter.getFilter().filter(null);
</code></pre>

blocks|key|1134856|text|试试看|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1134857|++++searchAutoComplete.setThreshold(0);
++++searchAutoComplete.addTextChangedListener(new+TextWatcher()+{
++++++++++++++++@Override
++++++++++++++++public+void+beforeTextChanged(CharSequence+charSequence,+int+i,+int+i1,+int+i2)+{
++++++++++++++++}

++++++++++++++++@Override
++++++++++++++++public+void+onTextChanged(CharSequence+charSequence,+int+i,+int+i1,+int+i2)+{//cut+last+probel
++++++++++++++++++++if+(charSequence.length()+>+1)+{
++++++++++++++++++++++++if+(charSequence.charAt(charSequence.length()+-+1)+==+'+')+{
++++++++++++++++++++++++++++searchAutoComplete.setText(charSequence.subSequence(0,+charSequence.length()+-+1));
++++++++++++++++++++++++++++searchAutoComplete.setSelection(charSequence.length()+-+1);
++++++++++++++++++++++++}
++++++++++++++++++++}
+++++++++++++++++++}


++++++++++++++++@Override
++++++++++++++++public+void+afterTextChanged(Editable+editable)+{
++++++++++++++++}
++++++++++++});


++++//when+clicked+in+autocomplete+text+view
++++++++@Override
++++++++public+void+onClick(View+view)+{
++++++++++++switch+(view.getId())+{
++++++++++++++case+R.id.header_search_etv:
++++++++++++++++++++if+(searchAutoComplete.getText().toString().length()+==+0)+{
++++++++++++++++++++++++searchAutoComplete.setText("+");
++++++++++++++++++++}
+++++++++++++break;
++++++++++++}
++++++++}):|code-block|syntax|javascript|1134858|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|$]]

try it 

<pre><code> searchAutoComplete.setThreshold(0);
 searchAutoComplete.addTextChangedListener(new TextWatcher() {
 @Override
 public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
 }

 @Override
 public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {//cut last probel
 if (charSequence.length() &gt; 1) {
 if (charSequence.charAt(charSequence.length() - 1) == ' ') {
 searchAutoComplete.setText(charSequence.subSequence(0, charSequence.length() - 1));
 searchAutoComplete.setSelection(charSequence.length() - 1);
 }
 }
 }


 @Override
 public void afterTextChanged(Editable editable) {
 }
 });


 //when clicked in autocomplete text view
 @Override
 public void onClick(View view) {
 switch (view.getId()) {
 case R.id.header_search_etv:
 if (searchAutoComplete.getText().toString().length() == 0) {
 searchAutoComplete.setText(" ");
 }
 break;
 }
 }):
</code></pre>

blocks|key|1350274|text|只需在autoCompleteTextView的触摸或单击事件上或在您想要的任何地方调用此方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1350275|autoCompleteTextView.showDropDown()|code-block|syntax|javascript|1350276|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|$]]

Just call this method on touch or click event of autoCompleteTextView or where you want.

<pre><code>autoCompleteTextView.showDropDown()
</code></pre>

blocks|key|1135006|text|只需将此代码粘贴到Java语言的onCreate方法中|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1135007|final+ArrayAdapter<String>+arrayAdapter+=+new+ArrayAdapter<>(
++++++++++++this,+android.R.layout.simple_spinner_dropdown_item,
++++++++++++getResources().getStringArray(R.array.Loc_names));

++++textView1+=(AutoCompleteTextView)+findViewById(R.id.acT1);
++++textView1.setAdapter(arrayAdapter);

++++textView1.setOnClickListener(new+View.OnClickListener()+{

++++++++@Override
++++++++public+void+onClick(final+View+arg0)+{
++++++++++++textView1.setMaxLines(5);
++++++++++++textView1.showDropDown();

++++++++}
++++});|code-block|syntax|javascript|1135008|这是你的Xml文件..。|1135009|<AutoCompleteTextView
++++++++++++android:layout_width="200dp"
++++++++++++android:layout_height="30dp"
++++++++++++android:hint="@string/select_location"
++++++++++++android:id="@%2Bid/acT1"
++++++++++++android:textAlignment="center"/>|1135010|并在string.xml中的Values下创建一个数组...|1135011|<string-array+name="Loc_names">

++++++++<item>Pakistan</item>
++++++++<item>Germany</item>
++++++++<item>Russia/NCR</item>
++++++++<item>China</item>
++++++++<item>India</item>
++++++++<item>Sweden</item>
++++++++<item>Australia</item>
++++</string-array>|1135012|你就可以走了。|1135013|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|W|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|Y|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

Just paste this to your onCreate Method in Java

<pre><code>final ArrayAdapter&lt;String&gt; arrayAdapter = new ArrayAdapter&lt;&gt;(
 this, android.R.layout.simple_spinner_dropdown_item,
 getResources().getStringArray(R.array.Loc_names));

 textView1 =(AutoCompleteTextView) findViewById(R.id.acT1);
 textView1.setAdapter(arrayAdapter);

 textView1.setOnClickListener(new View.OnClickListener() {

 @Override
 public void onClick(final View arg0) {
 textView1.setMaxLines(5);
 textView1.showDropDown();

 }
 });
</code></pre>

And this to your Xml file...

<pre><code>&lt;AutoCompleteTextView
 android:layout_width="200dp"
 android:layout_height="30dp"
 android:hint="@string/select_location"
 android:id="@+id/acT1"
 android:textAlignment="center"/&gt;
</code></pre>

And create an Array in string.xml under Values...

<pre><code>&lt;string-array name="Loc_names"&gt;

 &lt;item&gt;Pakistan&lt;/item&gt;
 &lt;item&gt;Germany&lt;/item&gt;
 &lt;item&gt;Russia/NCR&lt;/item&gt;
 &lt;item&gt;China&lt;/item&gt;
 &lt;item&gt;India&lt;/item&gt;
 &lt;item&gt;Sweden&lt;/item&gt;
 &lt;item&gt;Australia&lt;/item&gt;
 &lt;/string-array&gt;
</code></pre>

And you are good to go.

blocks|key|1350390|text|七年后，伙计们，问题依然存在。这里有一个类，它有一个函数，可以强制那个愚蠢的弹出窗口在任何情况下显示自己。您所需要做的就是为AutoCompleteTextView设置一个适配器，向其中添加一些数据，并随时调用showDropdownNow()函数。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1350391|致谢@David+Vávra。这是基于他的代码。|1350392|import+android.content.Context
import+android.util.AttributeSet
import+android.widget.AutoCompleteTextView

class+InstantAutoCompleteTextView+:+AutoCompleteTextView+{

++++constructor(context:+Context)+:+super(context)

++++constructor(context:+Context?,+attrs:+AttributeSet?)+:+super(context,+attrs)

++++constructor(context:+Context?,+attrs:+AttributeSet?,+defStyleAttr:+Int)+:+super(context,+attrs,+defStyleAttr)

++++override+fun+enoughToFilter():+Boolean+{
++++++++return+true
++++}

++++fun+showDropdownNow()+{
++++++++if+(adapter+!=+null)+{
++++++++++++//+Remember+a+current+text
++++++++++++val+savedText+=+text

++++++++++++//+Set+empty+text+and+perform+filtering.+As+the+result+we+restore+all+items+inside+of
++++++++++++//+a+filter's+internal+item+collection.
++++++++++++setText(null,+true)

++++++++++++//+Set+back+the+saved+text+and+DO+NOT+perform+filtering.+As+the+result+of+these+steps
++++++++++++//+we+have+a+text+shown+in+UI,+and+what+is+more+important+we+have+items+not+filtered
++++++++++++setText(savedText,+false)

++++++++++++//+Move+cursor+to+the+end+of+a+text
++++++++++++setSelection(text.length)

++++++++++++//+Now+we+can+show+a+dropdown+with+full+list+of+options+not+filtered+by+displayed+text
++++++++++++performFiltering(null,+0)
++++++++}
++++}
}|code-block|syntax|javascript|1350393|entityMap^0|2X|H|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|R|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|S|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|N|$]]

Seven years later, guys, the problem stays the same. Here's a class with a function which forces that stupid pop-up to show itself in any conditions. All you need to do is to set an adapter to your AutoCompleteTextView, add some data into it, and call <code>showDropdownNow()</code> function anytime.

Credits to @David Vávra. It's based on his code.

<pre><code>import android.content.Context
import android.util.AttributeSet
import android.widget.AutoCompleteTextView

class InstantAutoCompleteTextView : AutoCompleteTextView {

 constructor(context: Context) : super(context)

 constructor(context: Context?, attrs: AttributeSet?) : super(context, attrs)

 constructor(context: Context?, attrs: AttributeSet?, defStyleAttr: Int) : super(context, attrs, defStyleAttr)

 override fun enoughToFilter(): Boolean {
 return true
 }

 fun showDropdownNow() {
 if (adapter != null) {
 // Remember a current text
 val savedText = text

 // Set empty text and perform filtering. As the result we restore all items inside of
 // a filter's internal item collection.
 setText(null, true)

 // Set back the saved text and DO NOT perform filtering. As the result of these steps
 // we have a text shown in UI, and what is more important we have items not filtered
 setText(savedText, false)

 // Move cursor to the end of a text
 setSelection(text.length)

 // Now we can show a dropdown with full list of options not filtered by displayed text
 performFiltering(null, 0)
 }
 }
}
</code></pre>

blocks|key|1350478|text|在FocusChangeListener上，选中|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1350479|if+(hasFocus)+{
++++++++++++tvAutoComplete.setText("+")|code-block|syntax|javascript|1350480|在您的过滤器中，只需修剪此值：|1350481|filter+{+it.contains(constraint.trim(),+true)+}|1350482|当您关注此视图时，它将显示所有建议。|1350483|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

on FocusChangeListener, check
<pre><code>if (hasFocus) {
 tvAutoComplete.setText(&quot; &quot;)
</code></pre>
in your filter, just trim this value:
<pre><code>filter { it.contains(constraint.trim(), true) }
</code></pre>
and it will show all suggestion when you focus on this view.

blocks|key|1135303|text|对我来说，它是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1135304|+autoCompleteText.setThreshold(0);|code-block|syntax|javascript|1135305|做这个把戏吧。|1135306|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|$]]

For me, It is :
<pre><code> autoCompleteText.setThreshold(0);
</code></pre>
do the trick.

I am using <code>AutoCompleteTextView</code>, when the user clicks on it, I want to show suggestions even if it has no text - but <code>setThreshold(0)</code> works exactly the same as <code>setThreshold(1)</code> - so the user has to enter at least 1 character to show the suggestions.

Android: AutoCompleteTextView show suggestions when no text entered

我使用的是AutoCompleteTextView，当用户点击它时，我想要显示建议，即使它没有文本-但setThreshold(0)的工作原理与setThreshold(1)完全相同-所以用户必须输入至少1个字符才能显示建议。

问Android: AutoCompleteTextView在未输入文本时显示建议
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问Android: AutoCompleteTextView在未输入文本时显示建议
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