void android.view.View.setMeasuredDimension(int measuredWidth, int measuredHeight)

void android.view.View.measure(int widthMeasureSpec, int heightMeasureSpec)

void android.view.View.onMeasure(int widthMeasureSpec, int heightMeasureSpec)

void android.view.ViewGroup.onLayout(boolean changed, int l, int t, int r, int b)

android.view.View.MeasureSpec

package net.loonggg.viewgroup; 
 
import android.content.Context; 
import android.util.AttributeSet; 
import android.view.View; 
import android.view.ViewGroup; 
 
public class MyViewGroup extends ViewGroup { 
 
  public MyViewGroup(Context context) { 
    super(context); 
  } 
 
  public MyViewGroup(Context context, AttributeSet attrs) { 
    super(context, attrs); 
  } 
 
  public MyViewGroup(Context context, AttributeSet attrs, int defStyle) { 
    super(context, attrs, defStyle); 
  } 
 
  /** 
   * 计算控件的大小 
   */ 
  @Override 
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 
    super.onMeasure(widthMeasureSpec, heightMeasureSpec); 
    int measureWidth = measureWidth(widthMeasureSpec); 
    int measureHeight = measureHeight(heightMeasureSpec); 
    // 计算自定义的ViewGroup中所有子控件的大小 
    measureChildren(widthMeasureSpec, heightMeasureSpec); 
    // 设置自定义的控件MyViewGroup的大小 
    setMeasuredDimension(measureWidth, measureHeight); 
  } 
 
  private int measureWidth(int pWidthMeasureSpec) { 
    int result = 0; 
    int widthMode = MeasureSpec.getMode(pWidthMeasureSpec);// 得到模式 
    int widthSize = MeasureSpec.getSize(pWidthMeasureSpec);// 得到尺寸 
 
    switch (widthMode) { 
    /** 
     * mode共有三种情况，取值分别为MeasureSpec.UNSPECIFIED, MeasureSpec.EXACTLY, 
     * MeasureSpec.AT_MOST。 
     * 
     * 
     * MeasureSpec.EXACTLY是精确尺寸， 
     * 当我们将控件的layout_width或layout_height指定为具体数值时如andorid 
     * :layout_width="50dip"，或者为FILL_PARENT是，都是控件大小已经确定的情况，都是精确尺寸。 
     * 
     * 
     * MeasureSpec.AT_MOST是最大尺寸， 
     * 当控件的layout_width或layout_height指定为WRAP_CONTENT时 
     * ，控件大小一般随着控件的子空间或内容进行变化，此时控件尺寸只要不超过父控件允许的最大尺寸即可 
     * 。因此，此时的mode是AT_MOST，size给出了父控件允许的最大尺寸。 
     * 
     * 
     * MeasureSpec.UNSPECIFIED是未指定尺寸，这种情况不多，一般都是父控件是AdapterView， 
     * 通过measure方法传入的模式。 
     */ 
    case MeasureSpec.AT_MOST: 
    case MeasureSpec.EXACTLY: 
      result = widthSize; 
      break; 
    } 
    return result; 
  } 
 
  private int measureHeight(int pHeightMeasureSpec) { 
    int result = 0; 
 
    int heightMode = MeasureSpec.getMode(pHeightMeasureSpec); 
    int heightSize = MeasureSpec.getSize(pHeightMeasureSpec); 
 
    switch (heightMode) { 
    case MeasureSpec.AT_MOST: 
    case MeasureSpec.EXACTLY: 
      result = heightSize; 
      break; 
    } 
    return result; 
  } 
 
  /** 
   * 覆写onLayout，其目的是为了指定视图的显示位置，方法执行的前后顺序是在onMeasure之后，因为视图肯定是只有知道大小的情况下， 
   * 才能确定怎么摆放 
   */ 
  @Override 
  protected void onLayout(boolean changed, int l, int t, int r, int b) { 
    // 记录总高度 
    int mTotalHeight = 0; 
    // 遍历所有子视图 
    int childCount = getChildCount(); 
    for (int i = 0; i < childCount; i++) { 
      View childView = getChildAt(i); 
 
      // 获取在onMeasure中计算的视图尺寸 
      int measureHeight = childView.getMeasuredHeight(); 
      int measuredWidth = childView.getMeasuredWidth(); 
 
      childView.layout(l, mTotalHeight, measuredWidth, mTotalHeight 
          + measureHeight); 
 
      mTotalHeight += measureHeight; 
 
    } 
  } 
 
} 

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
  xmlns:tools="http://schemas.android.com/tools" 
  android:layout_width="match_parent" 
  android:layout_height="match_parent" 
  android:background="#00f0f0" 
  tools:context=".MainActivity" > 
 
  <net.loonggg.viewgroup.MyViewGroup 
    android:id="@+id/myViewGroup" 
    android:layout_width="480dp" 
    android:layout_height="300dp" 
    android:background="#0f0f0f" > 
 
    <TextView 
      android:layout_width="200dp" 
      android:layout_height="100dp" 
      android:background="#000000" 
      android:gravity="center" 
      android:text="第一个TextView" /> 
 
    <TextView 
      android:layout_width="100dp" 
      android:layout_height="200dp" 
      android:background="#ffffff" 
      android:gravity="center" 
      android:text="第二个TextView" /> 
  </net.loonggg.viewgroup.MyViewGroup> 
 
</RelativeLayout> 

package net.loonggg.viewgroup; 
 
import android.os.Bundle; 
import android.app.Activity; 
 
public class MainActivity extends Activity { 
 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
  } 
 
}