如果我要获取一个布局或者一个控件的宽高，但是在自定义View的构造方法中布局或者控件getMeasureHeight或者getHeight,什么的都是零，可是我自定义控件的时候一定要知道这个布局或者控件的宽高怎么办？以下测量一个布局为例子。
如class MyListView extends ListView{
public MyListView(Context context, AttributeSet attrs) {
LayoutInflater inflater = LayoutInflater.from(context);
LinearLayout headView = (LinearLayout) inflater.inflate(R.layout.head, null);
measureMyView(headView) ;//如果不添加该方法，以下宽高则都为零，加上此后能正确测量出该headView的宽高。
System.out.println("高度：" + headView.getMeasuredHeight()+" 宽度："+headView.getMeasuredWidth);
}
}
void measureMyView(View view) {
ViewGroup.LayoutParams params = view.getLayoutParams();
if (params == null) {
params = new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT,
ViewGroup.LayoutParams.WRAP_CONTENT);
}
int chidWidthSpec = ViewGroup.getChildMeasureSpec(0,0,params.width);
int lpHeight = params.height;
int childHeightSpec;
if (lpHeight > 0) {
childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY);
}else {
childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
}
view.measure(chidWidthSpec,childHeightSpec);
}