自定义 SquareView - children 与 match_parent 不一致 || wrap_content

Question

所以我需要一个始终为正方形的视图，因此我编写了以下自定义 class

public class SquareView extends LinearLayoutCompat
{
    public SquareView(Context context)
    {
        super(context);
    }

    public SquareView(Context context, AttributeSet attrs)
    {
        super(context, attrs);
    }

    public SquareView(Context context, AttributeSet attrs, int defStyleAttr)
    {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
    {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        int width  = getMeasuredWidth();
        int height = getMeasuredHeight();

        if (width > height)
        {
            setMeasuredDimension(width, width);
        }
        else
        {
            setMeasuredDimension(height, height);
        }
    }
}

但是，使用 match_parent 和 wrap_content 的视图的 children 不再正确运行

我该如何解决这个问题？

Answer 1

这是对更大问题的回答，而不是修复自定义视图的方法。

ConstraintLayout 支持调整子项的大小以具有特定的纵横比。如果你想要一个方形的 LinearLayout，你可以把它放在一个 ConstraintLayout 中并强制执行 1:1 纵横比。

https://developer.android.com/training/constraint-layout/index.html#adjust-the-view-size

Set size as a ratio

You can set the view size to a ratio such as 16:9 if at least one of the view dimensions is set to "match constraints" (0dp). To enable the ratio, click Toggle Aspect Ratio Constraint (callout 1 in figure 10), and then enter the width:height ratio in the input that appears.

If both the width and height are set to match constraints, you can click Toggle Aspect Ratio Constraint to select which dimension is based on a ratio of the other. The view inspector indicates which is set as a ratio by connecting the corresponding edges with a solid line.

For example, if you set both sides to "match constraints", click Toggle Aspect Ratio Constraint twice to set the width be a ratio of the height. Now the entire size is dictated by the height of the view (which can be defined in any way) as shown in figure 11.

自定义 SquareView - children 与 match_parent 不一致 || wrap_content

Custom SquareView - children not behaving with match_parent || wrap_content

android

android-layout

android-view

Set size as a ratio