Android -- 擷取View寬高

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在activity中可以調用View.getWidth、View.getHeight()、View.getMeasuredWidth() 、View.getgetMeasuredHeight()來獲得某個view的寬度或高度，但是在onCreate()、onStrart()、onResume()方法中會返回0，這是應為當前activity所代表的介面還沒顯示出來沒有添加到WindowPhone的DecorView上或要擷取的view沒有被添加到DecorView上或者該View的visibility屬性為gone 或者該view的width或height真的為0 ，所以只有上述條件都不成立時才能得到非0的width和height。

View的事件回調裡使用

這時候該view已經被顯示即被添加到DecorView上  如點擊事件  觸摸事件   焦時間點事件等

View view=findViewById(R.id.tv);      view.setOnClickListener(new OnClickListener() {                    @Override          public void onClick(View v) {              int width = v.getWidth();          }      });

onWindowFocusChanged() 回調

在activity被顯示出來時即添加到了DecorView上時擷取寬和高如onWindowFocusChanged() 回調方法

@Override  public void onWindowFocusChanged(boolean hasFocus) {      View iv1 = findViewById(R.id.iv1);      View iv2=findViewById(R.id.iv2);      String msg1="iv1‘ width:"+iv1.getWidth()+" height:"+iv1.getHeight()+"      measuredWidth:"+iv1.getMeasuredWidth()+"measuredHeight:"+iv1.getMeasuredHeight();      String msg2="iv2‘ width:"+iv2.getWidth()+" height:"+iv2.getHeight()+"      measuredWidth:"+iv2.getMeasuredWidth()+"measuredHeight:"+iv2.getMeasuredHeight();      Log.i("onWindowFocusChanged() "+msg1);      Log.i("onWindowFocusChanged() "+msg2);      super.onWindowFocusChanged(hasFocus);  }

延時

在onResume方法最後開線程300毫秒左右後擷取寬和高   因為onResume執行完後300毫秒後，介面就顯示出來了。

view.postDelayed(new Runnable() {                            @Override              public void run() {                  View iv1 = findViewById(R.id.iv1);                  View iv2=findViewById(R.id.iv2);                  String msg1="iv1‘ width:"+iv1.getWidth()+" height:"+iv1.getHeight()+"  measuredWidth:"+iv1.getMeasuredWidth()+"measuredHeight:"+iv1.getMeasuredHeight();                  String msg2="iv2‘ width:"+iv2.getWidth()+" height:"+iv2.getHeight()+"  measuredWidth:"+iv2.getMeasuredWidth()+"measuredHeight:"+iv2.getMeasuredHeight();                  Log.i("onWindowFocusChanged() "+msg1);                  Log.i("onWindowFocusChanged() "+msg2);              }          }, 300);

在onCreate()或onResume()等方法中需要

getViewTreeObserver().addOnGlobalLayoutListener()來添為view加回調在回調裡獲得寬度或者高度擷取完後讓view刪除該回調

view.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {                    @Override          public void onGlobalLayout() {              view.postDelayed(new Runnable() {                                    @Override                  public void run() {                      View iv1 = findViewById(R.id.iv1);                      View iv2=findViewById(R.id.iv2);                      String msg1="iv1‘ width:"+iv1.getWidth()+" height:"+iv1.getHeight()+"  measuredWidth:"+iv1.getMeasuredWidth()+"measuredHeight:"+iv1.getMeasuredHeight();                      String msg2="iv2‘ width:"+iv2.getWidth()+" height:"+iv2.getHeight()+"  measuredWidth:"+iv2.getMeasuredWidth()+"measuredHeight:"+iv2.getMeasuredHeight();                      Log.i("onWindowFocusChanged() "+msg1);                      Log.i("onWindowFocusChanged() "+msg2);                  }              }, 300);          }      });

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參考：http://blog.csdn.net/nailsoul/article/details/25909313

Android -- 擷取View寬高