Android百分比布局(PercentRelativeLayout)嵌套NavigationView自定义宽度

因为NavigationView必须嵌套在DrawerLayout里，当DrawerLayout不是根布局时，就没办法用match_parent等定义宽高，会报错。所以要重写DrawerLayout的onMeasure()方法：

public class MyDrawerLayout extends DrawerLayout {
    public MyDrawerLayout(@NonNull Context context) {
        super(context);
    }

    public MyDrawerLayout(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public MyDrawerLayout(@NonNull Context context, @Nullable AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        widthMeasureSpec = MeasureSpec.makeMeasureSpec(
                MeasureSpec.getSize(widthMeasureSpec), MeasureSpec.EXACTLY);
        heightMeasureSpec = MeasureSpec.makeMeasureSpec(
                MeasureSpec.getSize(heightMeasureSpec), MeasureSpec.EXACTLY);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
}

（以上代码copy的）

然后进行嵌套布局：

但是吧，NavigationView的宽度要比DrawerLayout小一点，待补充。