动态设置布局

设计图是这样的

下面的卡片需要占上面的背景的一半

以前都是把下面卡片的大小写死,然后设置一个负的marginTop

但是现在想这么写的时候,突然感觉有点low,所以就换了一种写法

layoutTop是上面的根布局

layoutMoney是下面卡片的根布局

mBackground是背景图片

/**
 * 设置背景高度
 */
private void refreshBackground() {
    //SDK大于16
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
        layoutTop.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                if (layoutTop != null) {
                    final int heightEv = layoutTop.getMeasuredHeight();
                    layoutMoney.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
                        @Override
                        public void onGlobalLayout() {
                            if (layoutMoney != null) {
                                int heightHeader = layoutMoney.getMeasuredHeight();
                                RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams
                                        (ViewGroup.LayoutParams.MATCH_PARENT, (int)
//卡片设置了marginTop  20dp,所以要加上这个marginTop的距离
 (heightEv + DeviceUtils.dip2px(getContext(), 20) + (heightHeader + 0f) / 2));
                                mBackground.setLayoutParams(params);
                            }
                            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                                if (layoutMoney != null) {
                                    layoutMoney.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                                }
                            }
                        }
                    });
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                        layoutTop.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                    }
                }

            }
        });
    } else {
        //SKD小于16的时候头布局背景为包裹内容
        RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        mBackground.setLayoutParams(params);
    }
}

最后在onResume()中调用就好了