通过MeasuerSpec获取View的宽度和高度

    在onCreate中无法通过getHeight方法获取View的宽高。我们可以通过MeasureSpec实现。

int w = View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED);  

int h = View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED);  

textView.measure(w, h);  

int width =textView.getMeasuredWidth();  

int height =textView.getMeasuredHeight();  

MeasureSpec类详解