/**  *  * 自定義一個4*3的撥打電話的布局控件,  *  *  */ public class MyPhoneCard extends ViewGroup{      private static final int COLUMNS = 3;   private static final int ROWS = 4;   private static final int NUM_BUTTON = COLUMNS*ROWS;      private View[] mButtons = new View[NUM_BUTTON];      private int mButtonWidth;   private int mButtonHeight;   private int mPaddingLeft;   private int mPaddingRight;   private int mPaddingTop;   private int mPaddingBottom;   private int mWidthInc;   private int mHeightInc;   private int mWidth;   private int mHeight;    public MyPhoneCard(Context context) {     super(context);   }      public MyPhoneCard(Context context, AttributeSet attrs){     super(context,attrs);   }      public MyPhoneCard(Context context, AttributeSet attrs, int defStyle){     super(context,attrs,defStyle);   }      /**    * 當從xml將所有的控件都調入內存后，觸發的動作    * 在這里獲取控件的大小，并計算整個ViewGroup需要的總的寬和高    */   @Override   protected void onFinishInflate(){     super.onFinishInflate();     final View[] btns = mButtons;          for(int i=0; i<NUM_BUTTON; i++){       btns[i] = this.getChildAt(i);       btns[i].measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);     }          //緩存大小     final View child = btns[0];     mButtonWidth = child.getMeasuredWidth();     mButtonHeight = child.getMeasuredHeight();     mPaddingLeft = this.getPaddingLeft();     mPaddingRight = this.getPaddingRight();     mPaddingTop = this.getPaddingTop();     mPaddingBottom = this.getPaddingBottom();     mWidthInc = mButtonWidth + mPaddingLeft + mPaddingRight;     mHeightInc = mButtonHeight + mPaddingTop + mPaddingBottom;          mWidth = mWidthInc*COLUMNS;     mHeight = mHeightInc*ROWS;          Log.v("Finish Inflate:", "btnWidth="+mButtonWidth+",btnHeight="+mButtonHeight+",padding:"+mPaddingLeft+","+mPaddingTop+","+mPaddingRight+","+mPaddingBottom);              }      /**    * 這個方法在onFinishInflate之后，onLayout之前調用。這個方面調用兩次    */   @Override   protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){     super.onMeasure(widthMeasureSpec, heightMeasureSpec);     Log.v("ViewGroup SIZE：width=", mWidth+"");     Log.v("ViewGroup SIZE: height=",mHeight+"");     final int width = resolveSize(mWidth, widthMeasureSpec);//傳入我們希望得到的寬度，得到測量后的寬度     final int height = resolveSize(mHeight,heightMeasureSpec);//傳入我們希望得到的高度，得到測量后的高度     Log.v("ViewGroup Measured SIZE: width=", width+"");     Log.v("ViewGroup Measured SIZE: height=", height+"");     //重新計算后的結果，需要設置。下面這個方法必須調用     setMeasuredDimension(width, height);   }    /**    * 這個方法在onMeasure之后執行，這個自定義控件中含有12個子控件（每個小鍵），所以，重寫這個方法，    * 調用每個鍵的layout，將他們一個一個布局好    * 就是4*3的放置，很簡單，一個嵌套循環搞定    */   @Override   protected void onLayout(boolean changed, int left, int top, int right, int bottom) {     final View[] buttons = mButtons;     int i = 0;     Log.v("BOTTOM:", bottom+"");     Log.v("TOP", top+"");          int y = (bottom - top) - mHeight + mPaddingTop;//這里其實bottom-top=mHeight,所以y=mPaddingTop     Log.v("Y=", y+"");     for(int row=0; row<ROWS; row++){       int x = mPaddingLeft;       for(int col = 0; col < COLUMNS; col++){         buttons[i].layout(x, y, x+mButtonWidth, y+mButtonHeight);         x = x + mWidthInc;         i++;       }       y = y + mHeightInc;     }   }  } 

<?xml version="1.0" encoding="utf-8"?> <demo.phone.card.MyPhoneCard  xmlns:android="http://schemas.android.com/apk/res/android"   android:id = "@+id/dialpad"   android:paddingLeft="7dp"   android:paddingRight="7dp"   android:paddingTop="6dp"   android:paddingBottom="6dp"   android:layout_gravity="center"   android:layout_width="wrap_content"  android:layout_height="wrap_content"   android:layout_marginBottom="5dp">     <ImageButton android:id="@+id/one"      android:src="@drawable/dial_num_1_no_vm"      style="@style/dial_btn_style"      />        <ImageButton android:id="@+id/two"      android:src="@drawable/dial_num_2"      style="@style/dial_btn_style"/>         <ImageButton android:id="@+id/three"      android:src="@drawable/dial_num_3"      style="@style/dial_btn_style"/>         <ImageButton android:id="@+id/four"      android:src="@drawable/dial_num_4"      style="@style/dial_btn_style"/>         <ImageButton android:id="@+id/five"      android:src="@drawable/dial_num_5"      style="@style/dial_btn_style"/>        <ImageButton android:id="@+id/six"      android:src="@drawable/dial_num_6"      style="@style/dial_btn_style"/>         <ImageButton android:id="@+id/seven"      android:src="@drawable/dial_num_7"      style="@style/dial_btn_style"/>        <ImageButton android:id="@+id/eight"      android:src="@drawable/dial_num_8"      style="@style/dial_btn_style"/>        <ImageButton android:id="@+id/nine"      android:src="@drawable/dial_num_9"      style="@style/dial_btn_style"/>         <ImageButton android:id="@+id/star"      android:src="@drawable/dial_num_star"      style="@style/dial_btn_style"/>          <ImageButton android:id="@+id/zero"      android:src="@drawable/dial_num_0"      style="@style/dial_btn_style"/>          <ImageButton android:id="@+id/pound"      android:src="@drawable/dial_num_pound"      style="@style/dial_btn_style"/>                                                       </demo.phone.card.MyPhoneCard>