获取view的高和宽

在有些地方，如onCreate或者listAdapter的getView里，view未绘制，那么无法通过调用getHeight或者getHeight来获取view的尺寸。view在显示之前需要经过measure和requestLayout的步骤，也就是在显示前需要被测量。因此可以通过如下方法来获得view尺寸：

public static int getWidth(View v){int width = View.MeasureSpec.makeMeasureSpec(0,        View.MeasureSpec.UNSPECIFIED);int height = View.MeasureSpec.makeMeasureSpec(0,        View.MeasureSpec.UNSPECIFIED);v.measure(width, height);return v.getMeasuredWidth();}public static int getHeight(View v){int width = View.MeasureSpec.makeMeasureSpec(0,        View.MeasureSpec.UNSPECIFIED);int height = View.MeasureSpec.makeMeasureSpec(0,        View.MeasureSpec.UNSPECIFIED);v.measure(width, height);return v.getMeasuredHeight();}