[AndroidLayout] getWidth() and getHeight() return 0

getWidth()
取得 view 的實際所佔寬度。

getMeasuredWidth()
view 在 parent 估計會佔的寬度，是最近一次在 measure() 中計算的值。

Solution1

final TextView tv = (TextView)findViewById(R.id.image_test);
ViewTreeObserver vto = tv.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

    @Override
    public void onGlobalLayout() {
        LayerDrawable ld = (LayerDrawable)tv.getBackground();
        ld.setLayerInset(1, 0, tv.getHeight() / 2, 0, 0);
        ViewTreeObserver obs = tv.getViewTreeObserver();
        obs.removeGlobalOnLayoutListener(this);
    }
});

Solution2
[AndroidLayout] getWidth() and getHeight()


* Reference
- getWidth和getMeasuredWidth的正解 - rui313的专栏 - 博客频道 - CSDN.NET
- android - How do you to retrieve dimensions of a view? Getheight() and Getwidth() always return zero - Stack Overflow
- Android初级教程_获取Android控件的宽和高 **