宽度会变的自定义LinearLayout

您可以创建一个自定义LinearLayout并覆盖onMeasure方法来实现宽度可变的效果。在这个方法中，您可以通过调整子视图的大小和位置来改变LinearLayout的大小。

以下是一个示例代码：

public class CustomLinearLayout extends LinearLayout {

    private int mMaxWidth = Integer.MAX_VALUE; // 默认最大宽度

    public CustomLinearLayout(Context context) {
        super(context);
    }

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

    public void setMaxWidth(int maxWidth) {
        mMaxWidth = maxWidth;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int measuredWidth = 0, measuredHeight = 0, childWidth, childHeight;
        int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        int heightMode = MeasureSpec.getMode(heightMeasureSpec);

        // 测量子视图
        measureChildren(widthMeasureSpec, heightMeasureSpec);

        // 计算子视图占用的空间
        int childCount = getChildCount();
        for (int i = 0; i < childCount; i++) {
            View child = getChildAt(i);
            MarginLayoutParams params = (MarginLayoutParams) child.getLayoutParams();
            childWidth = child.getMeasuredWidth() + params.leftMargin + params.rightMargin;
            childHeight = child.getMeasuredHeight() + params.topMargin + params.bottomMargin;
            measuredWidth += childWidth;
            measuredHeight = Math.max(measuredHeight, childHeight);
        }

        // 调整LinearLayout的大小
        if (widthMode == MeasureSpec.EXACTLY) {
            measuredWidth = Math.min(measuredWidth, MeasureSpec.getSize(widthMeasureSpec));
        }
        measuredWidth = Math.min(measuredWidth, mMaxWidth);
        setMeasuredDimension(measuredWidth, measuredHeight);
    }
}

您可以在布局文件中使用CustomLinearLayout并为其设置最大宽度：

<com.example.CustomLinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    app:maxWidth="500dp">

    <!-- 添加子视图 -->

</com.example.CustomLinearLayout>