blocks|key|971994|text|在android中，视图只有在渲染完成时才会分配宽度和高度。所以，除非你的list至少呈现一次，否则你不会得到listItemHeight。问题的解决方案可能是设置列表项的最小高度，以便至少有一些东西可用，而不是硬编码高度和宽度。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|971995|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

In android a view is assigned Width and Height only when its rendering is complete. So unless you list is rendered atleast once you won't get listItemHeight. Solution to your problem could be that you set some min Height of list Item so that you have atleast something to work with instead of Hard Coding height and width.

blocks|key|972028|text|试试这个，它会对你有用的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|972029|private+static+final+int+UNBOUNDED+=+MeasureSpec.makeMeasureSpec(0,+MeasureSpec.UNSPECIFIED);

//+To+calculate+the+total+height+of+all+items+in+ListView+call+with+items+=+adapter.getCount()
public+static+int+getItemHeightofListView(ListView+listView,+int+items)+{
++++ListAdapter+adapter+=+listView.getAdapter();

++++int+grossElementHeight+=+0;
++++for+(int+i+=+0;+i+<+items;+i%2B%2B)+{
++++++++View+childView+=+adapter.getView(i,+null,+listView);
++++++++childView.measure(UNBOUNDED,+UNBOUNDED);
++++++++grossElementHeight+%2B=+childView.getMeasuredHeight();
++++}
++++return+grossElementHeight;
}|code-block|syntax|javascript|972030|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 this, it will work for you. 

<pre><code>private static final int UNBOUNDED = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);

// To calculate the total height of all items in ListView call with items = adapter.getCount()
public static int getItemHeightofListView(ListView listView, int items) {
 ListAdapter adapter = listView.getAdapter();

 int grossElementHeight = 0;
 for (int i = 0; i &lt; items; i++) {
 View childView = adapter.getView(i, null, listView);
 childView.measure(UNBOUNDED, UNBOUNDED);
 grossElementHeight += childView.getMeasuredHeight();
 }
 return grossElementHeight;
}
</code></pre>

blocks|key|972107|text|正如hariseldon78上面指出的，这些解决方案都不能解决真正的问题，即在呈现列表项之前确定列表项行的高度。我遇到了同样的问题，因为我想将一些图像缩放到ListView项目行的高度，而不想将它们缩放到固定值。如果主题导致行布局中其他部分的文本高度发生变化，那么我想要这个高度，以便在适配器的getView例程中可以相应地调整bmap的大小。我一直在努力解决getHeight和所有测量到的高度报告为零的问题，直到该行被呈现。FOr+me后来看到正确的高度已经太晚了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|972108|我的解决方案是第一次通过getView创建一个onLayoutChangedListener()，并且只针对第0行。侦听器将在第一个位置(0)的getView执行完成后立即触发，此时"bottom“参数将告诉您行的高度。我将其记录在一个自定义适配器类变量中，这样它就可以作为一个height参数使用，而不必再次获取height。|972109|侦听器将自身注销作为其执行的一部分。这为行1-N提供了适当的高度，但不为行0提供了适当的高度。对于第0排，我做了一些非常糟糕的事情。在设置了另一个自定义适配器类变量来控制递归之后，我让侦听器再次为行0调用getView。第二次运行getView(0)时，它不会设置侦听器，而是会找到一个有效的高度参数进行操作，一切都是正常的。|972110|代码如下--不需要告诉我这有多糟糕--如果android不是很难判断我创建的视图有多大，当我完成了基于表面渲染参数的视图填充时，我就不需要做这个丑陋的事情了，但它是有效的。如果代码格式很糟糕，很抱歉...|972111|int+mHeight+=+0;

@Override
public+View+getView(final+int+position,+View+convertView,+ViewGroup+parent)+{
...+usual+boiler+plate+stuff
++++//+JUST+THE+FIRST+TIME
++++if+(position+==+0+&&+mHeight+==+0)+{
++++++++final+View+ref+=+convertView;
++++++++convertView.addOnLayoutChangeListener(new+View.OnLayoutChangeListener()+{
++++++++++++public+void+onLayoutChange(View+v,+int+left,+int+top,+int+right,
+++++++++++++++++++int+bottom,+int+oldLeft,+int+oldTop,+int+oldRight,+int+oldBottom)+{
++++++++++++++++++++ref.removeOnLayoutChangeListener(this);
++++++++++++++++++++mHeight+=+bottom;
++++++++++++++++++++firstTime+=+false;

++++++++++++++++++++//++NOW+LETS+REGET+THE+FIRST+VIEW+WITH+THE+HEIGHT+CORRECT
++++++++++++++++++++int+visiblePosition+=+getListView().getFirstVisiblePosition();
++++++++++++++++++++View+view+=+getListView().getChildAt(0+-+visiblePosition);
++++++++++++++++++++getListAdapter().getView(0,+view,+getListView());
++++++++++++++++++++//+RECURSION+LOL
++++++++++++}
++++++++});
++++}

++++//+Configure+the+view+for+this+row
++++....

++++//+HOW+BIG+IS+THE+VIEW?
++++//+NOW+IF+NOT+FIRSTTIME+(MHEIGHT+!=+0)
++++if+(mHeight+!=+0)+{
++++++++//+DO+OUR+IMAGE+SETUP+HERE+CAUSE+mHeight+is+RIGHT!
++++++++Log.d(TAG,+"mHeight="+%2B+mHeight);
++++}

++++++++return+convertView;
}|code-block|syntax|javascript|972112|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|Q|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|R|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|S|8|@]|9|@]|A|$K|L]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

As hariseldon78 above points out none of these solutions fix the REAL problem which is determining the height of the list item row BEFORE it is rendered. I had the same problem as I wanted to scale some images to the height of my ListView item rows, and did not want to scale them to a fixed value. If the theme caused the text in other parts of my row layout to vary in height, I wanted the height so that in my getView routine of my adapter I could resize the bmap accordingly. I was struggling with the problem that getHeight and all the measured heights report zero until the row has been rendered. FOr me seeing the heights correct later was too late.

My solution is to create an onLayoutChangedListener() the first time through getView and only for row 0. The listener will trigger as soon as getView for the first position (0) completes executing, and at that time the "bottom" parameter will tell you the height of the row. I record this in a custom adapter class variable so it is available as a height parameter without having to fetch the height again.

The listener unregisters itself as part of its execution. This provides the proper height for rows 1-N but not for row zero. For row zero I did something really nasty. I had my listener call getView AGAIN for row 0 after setting another custom adapter class variable to control the recursion. The second time getView(0) runs it will not setup the listener, and will find a valid parameter for height to operate with and all is good.

Code is below - no need to tell me how AWFUL this is - if android didn't have to make it so freaking hard to tell how big the view I am creating is when I am done populating the view's based on the rendering parms for the surface I wouldn't have to do this ugliness but it works. Sorry if the code formatting is awful ...

<pre><code>int mHeight = 0;

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
... usual boiler plate stuff
 // JUST THE FIRST TIME
 if (position == 0 &amp;&amp; mHeight == 0) {
 final View ref = convertView;
 convertView.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
 public void onLayoutChange(View v, int left, int top, int right,
 int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
 ref.removeOnLayoutChangeListener(this);
 mHeight = bottom;
 firstTime = false;

 // NOW LETS REGET THE FIRST VIEW WITH THE HEIGHT CORRECT
 int visiblePosition = getListView().getFirstVisiblePosition();
 View view = getListView().getChildAt(0 - visiblePosition);
 getListAdapter().getView(0, view, getListView());
 // RECURSION LOL
 }
 });
 }

 // Configure the view for this row
 ....

 // HOW BIG IS THE VIEW?
 // NOW IF NOT FIRSTTIME (MHEIGHT != 0)
 if (mHeight != 0) {
 // DO OUR IMAGE SETUP HERE CAUSE mHeight is RIGHT!
 Log.d(TAG, "mHeight=" + mHeight);
 }

 return convertView;
}
</code></pre>

blocks|key|972144|text|Dwivedi+Ji代码的优化版本，带有分隔符高度，没有不必要的参数：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|972145|private+int+calculateHeight(ListView+list)+{

++++int+height+=+0;

++++for+(int+i+=+0;+i+<+list.getCount();+i%2B%2B)+{
++++++++View+childView+=+list.getAdapter().getView(i,+null,+list);
++++++++childView.measure(MeasureSpec.makeMeasureSpec(0,+MeasureSpec.UNSPECIFIED),+MeasureSpec.makeMeasureSpec(0,+MeasureSpec.UNSPECIFIED));
++++++++height%2B=+childView.getMeasuredHeight();
++++}

++++//dividers+height
++++height+%2B=+list.getDividerHeight()+*+list.getCount();

++++return+height;
}|code-block|syntax|javascript|972146|entityMap^0|0|A|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|$]]

optimized version of <code>Dwivedi Ji</code>'s code with dividers height and without unnecessary params:

<pre><code>private int calculateHeight(ListView list) {

 int height = 0;

 for (int i = 0; i &lt; list.getCount(); i++) {
 View childView = list.getAdapter().getView(i, null, list);
 childView.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
 height+= childView.getMeasuredHeight();
 }

 //dividers height
 height += list.getDividerHeight() * list.getCount();

 return height;
}
</code></pre>

Is there a way to get ListViewItem height in code, when there is no actual items in list?

My ListViewItem layout: 

<pre><code>&lt;LinearLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="?android:attr/listPreferredItemHeight"&gt;
...
&lt;/LinearLayout&gt; 
</code></pre>

I have tried to get it using Inflater: 

<pre><code>View convertView = LayoutInflater.from( this )
 .inflate( R.layout.mail_list_row, null );
int itemHeight = convertView.getHeight();
</code></pre>

But it's return 0;

Thanks!

Android - Get ListView item height?

当列表中没有实际的项目时，有没有办法在代码中获取ListViewItem的高度？我的ListViewItem布局：<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fi...

问安卓-获取ListView项目高度？
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