TextView高度= wrap_content不工作

<ScrollView
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="文本内容" />

</ScrollView>

public class WrapContentTextView extends TextView {

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

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

    public WrapContentTextView(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();
        setMeasuredDimension(width, height);
    }
}