安卓零碎知识集中（2）

1、获取标题栏的高度

		Rect frame = new Rect();
			getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);
			int statusBarHeight = frame.top;

			int contentTop = getWindow().findViewById(Window.ID_ANDROID_CONTENT)
					.getTop();
			int titleBarHeight = contentTop - statusBarHeight;
			textView.setText("statusBarHeight" + statusBarHeight + ";contentTop="
					+ contentTop + ";titleBarHeight" + titleBarHeight);
			

注：该类必须继承ActivityGroup

LocalActivityManager activityManager;
activityManager = getLocalActivityManager();
View view2 = activityManager.startActivity("act2",new Intent(this, Act2.class)).getDecorView();
linearLayout.addView(view2, new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));

		View view = getWindow().getDecorView();
		Bitmap bitmap = Bitmap.createBitmap(view.getWidth(),
		view.getHeight(), Config.RGB_565);  
                view.draw(new Canvas(bitmap));
              	imageView.setImageBitmap(bitmap);

4、android 获取组件尺寸大小

在oncreate()中利用view.getWidth()或是view.getHeiht()来获取view的宽和高，看似没有问题，其实他们去得值是0，并不是你想要的结果？

这是为什么呢？

在调用oncreate()方法时，界面处于不可见状态，内存加载组件还没有绘制出来，你是无法获取他的尺寸。

那如何在绘制组件之前能获取到该组件的尺寸大小呢？

这里有三种方法，经过验证的：

（1）

int width =View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED); 
int height =View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED); 
view.measure(width,height); 
int height=view.getMeasuredHeight(); 
int width=view.getMeasuredWidth();

//增加组件绘制之前的监听
ViewTreeObserver vto =view.getViewTreeObserver(); 
vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() { 
   @Override
    public booleanonPreDraw() { 
       int height =view.getMeasuredHeight(); 
       int width =view.getMeasuredWidth();     
   } 
}); 

//增加整体布局监听
ViewTreeObserver vto = view.getViewTreeObserver();  
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener(){ 
    @Override 
    public voidonGlobalLayout() { 
      view.getViewTreeObserver().removeGlobalOnLayoutListener(this);      
    int height =view.getMeasuredHeight(); 
     int width =view.getMeasuredWidth();  
    }  
});

安卓零碎知识集中（2）

原文：http://blog.csdn.net/scboyhj__/article/details/40212181