android在OnCreate中擷取控制項的寬度和高度

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一個demo，在xml布局中，某一行的高度為其他行的一半。之前用layout_weight，得出的效果也不太理想。

<?xml version="1.0" encoding="UTF-8"?>  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"       android:layout_width="match_parent"       android:layout_height="match_parent"     android:orientation="vertical" >           <LinearLayout         android:layout_width="match_parent"        android:layout_height="wrap_content"        android:background="#ff0000"        android:layout_weight="2"        >        <TextView           android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="1"        android:textColor="@android:color/white"        />    </LinearLayout>        <LinearLayout         android:layout_width="match_parent"        android:layout_height="wrap_content"android:background="#cccccc"        android:layout_weight="2"        >        <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="2"        android:textColor="@android:color/black" />    </LinearLayout>        <LinearLayout         android:layout_width="match_parent"        android:layout_height="wrap_content"android:background="#ddaacc"        android:layout_weight="1"        >        <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="3"        android:textColor="@android:color/black"         />    </LinearLayout>         <LinearLayout         android:layout_width="match_parent"        android:layout_height="wrap_content"android:background="#000"        android:layout_weight="1"        >        <TextView           android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="4"        android:textColor="@android:color/white"          />     </LinearLayout>     </LinearLayout> 

儘管有效果了，但是如果裡面的內容過多的話，這個布局就不起作用了。所以我們根據手機螢幕的大小  動態設定它的高度。

<pre name="code" class="java">public class HomeActivity extends Activity{private LinearLayout homelayout; //父private LinearLayout home1;private LinearLayout home2;private LinearLayout home3;private LinearLayout home4;boolean hasMeasured = false;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_home);home1 = (LinearLayout)findViewById(R.id.home_content_section1);home2 = (LinearLayout)findViewById(R.id.home_content_section2);home3 = (LinearLayout)findViewById(R.id.home_content_section3);home4 = (LinearLayout)findViewById(R.id.home_content_section4);homelayout = (LinearLayout)findViewById(R.id.home_content);ViewTreeObserver vto = homelayout.getViewTreeObserver();vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {@Overridepublic boolean onPreDraw() {if (hasMeasured == false)                {//擷取homelayout的寬度和高度                int height = homelayout.getMeasuredHeight();                //int width = homelayout.getMeasuredWidth();                android.view.ViewGroup.LayoutParams lp1 =home1.getLayoutParams();                lp1.height=height*2/7;                android.view.ViewGroup.LayoutParams lp2 =home2.getLayoutParams();                lp2.height=height*2/7;                android.view.ViewGroup.LayoutParams lp3 =home3.getLayoutParams();                lp3.height=height*1/7;                android.view.ViewGroup.LayoutParams lp4 =home4.getLayoutParams();                lp4.height=height*2/7;                hasMeasured = true;                }return true;}});}

android在OnCreate中擷取控制項的寬度和高度