【Android】擷取控制項的寬和高

標籤：i++   string   ongl   append   getview   view   word   observer   pre   

      有時候我們須要在Activity的時候擷取控制項的寬和高來做一些操作，以下介紹三種擷取寬和高的方式：

1. onWindowFocusChanged

@Override    public void onWindowFocusChanged(boolean hasFocus)    {        super.onWindowFocusChanged(hasFocus);        if (hasFocus)        {            int width = image.getMeasuredWidth();            int height = image.getMeasuredHeight();            Toast.makeText(MainActivity.this, "width = " + width + "---height = " + height, Toast.LENGTH_SHORT).show();        }    }

2. post方式

 @Override    protected void onStart()    {        super.onStart();        image.post(new Runnable()        {            @Override            public void run()            {                int width = image.getMeasuredWidth();                int height = image.getMeasuredHeight();                Toast.makeText(MainActivity.this, "onstart--width = " + width + "---height = " + height, Toast.LENGTH_SHORT).show();            }        });    }

3. ViewTreeObserver

 ViewTreeObserver observer = image.getViewTreeObserver();        observer.addOnGlobalLayoutListener(new OnGlobalLayoutListener()        {            @Override            public void onGlobalLayout()            {                image.getViewTreeObserver().removeGlobalOnLayoutListener(this);                int width = image.getMeasuredWidth();                int height = image.getMeasuredHeight();                Toast.makeText(MainActivity.this, "onglobal--width = " + width + "---height = " + height, Toast.LENGTH_SHORT).show();            }        });

備忘：以上image是ImageView控制項

ImageView image = (ImageView)findViewById(R.id.image);

【Android】擷取控制項的寬和高