android獲取view寬高的幾種方法

在onCreate方法中我們通過mView.getWidth()和mView.getHeight()獲取到的view的寬高都是0，那么下面幾種方法就可以在onCreate方法中獲取到view的寬高。

1、

        int w = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        int h = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        mTextView.measure(w, h);
        int height = mTextView.getMeasuredHeight();
        int width = mTextView.getMeasuredWidth();
        System.out.println("measure width=" + width + " height=" + height);

2、mViewTreeObserver = mTextView.getViewTreeObserver();

        mViewTreeObserver.addOnGlobalLayoutListener(new OnGlobalLayoutListener()
        {
            @Override
            public void onGlobalLayout()
            {
                // TODO Auto-generated method stub
                mTextView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
                System.out.println("onGlobalLayout width=" + mTextView.getWidth() + " height=" + mTextView.getHeight());
            }
        });

3、

        mViewTreeObserver.addOnPreDrawListener(new OnPreDrawListener()
        {
            @Override
            public boolean onPreDraw()
            {
                // TODO Auto-generated method stub
                mTextView.getViewTreeObserver().removeOnPreDrawListener(this);
                System.out.println("onPreDraw width=" + mTextView.getWidth() + " height=" + mTextView.getHeight());
                return true;
            }
        });

4、

    @Override
    public void onWindowFocusChanged(boolean hasFocus)
    {
        // TODO Auto-generated method stub
        super.onWindowFocusChanged(hasFocus);
        if (hasFocus)
        {
            System.out.println("onWindowFocusChanged width=" + mTextView.getWidth() + " height=" + mTextView.getHeight());
        }
    }

打印結果：