背景
我有一个自定义的ViewGroup子类,它旋转并镜像它的子视图。这样做的目的是正确地display traditional Mongolian text
我可以把任何东西都放到这个ViewGroup,但对于我当前的项目,我正在把一个EditText放进去。(I was never successful直接旋转和镜像EditText。但是,将其包装在此自定义视图组中确实有效。)
问题
我的问题是,当我试图以编程方式调整ViewGroup的大小时,它的子视图并没有随它一起正确地调整大小。我希望EditText与父ViewGroup的大小匹配,以便它看起来是单个视图。
MCVE
我做了一个新项目来说明这个问题。该按钮增加视图组的宽度(显示为红色)。图像显示项目开始(一切正常)和两个宽度增量。EditText为白色,即使宽度和高度设置为match_parent也不会调整大小。
android - 在自定义ViewGroup子类中调整旋转后的 subview 的大小-LMLPHP
完整的项目代码如下。
mongolviewgroup.java(旋转和镜像其内容的自定义viewgroup)

public class MongolViewGroup extends ViewGroup {

    private int angle = 90;
    private final Matrix rotateMatrix = new Matrix();
    private final Rect viewRectRotated = new Rect();
    private final RectF tempRectF1 = new RectF();
    private final RectF tempRectF2 = new RectF();
    private final float[] viewTouchPoint = new float[2];
    private final float[] childTouchPoint = new float[2];
    private boolean angleChanged = true;

    public MongolViewGroup(Context context) {
        this(context, null);
    }

    public MongolViewGroup(Context context, AttributeSet attrs) {
        super(context, attrs);
        setWillNotDraw(false);
    }

    public View getView() {
        return getChildAt(0);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        final View view = getView();
        if (view != null) {
            measureChild(view, heightMeasureSpec, widthMeasureSpec);
            setMeasuredDimension(resolveSize(view.getMeasuredHeight(), widthMeasureSpec),
                    resolveSize(view.getMeasuredWidth(), heightMeasureSpec));
        } else {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        if (angleChanged) {
            final RectF layoutRect = tempRectF1;
            final RectF layoutRectRotated = tempRectF2;
            layoutRect.set(0, 0, right - left, bottom - top);
            rotateMatrix.setRotate(angle, layoutRect.centerX(), layoutRect.centerY());
            rotateMatrix.postScale(-1, 1);
            rotateMatrix.mapRect(layoutRectRotated, layoutRect);
            layoutRectRotated.round(viewRectRotated);
            angleChanged = false;
        }
        final View view = getView();
        if (view != null) {
            view.layout(viewRectRotated.left, viewRectRotated.top, viewRectRotated.right,
                    viewRectRotated.bottom);
        }
    }


    @Override
    protected void dispatchDraw(Canvas canvas) {

        canvas.save();
        canvas.rotate(-angle, getWidth() / 2f, getHeight() / 2f);
        canvas.scale(-1, 1);
        super.dispatchDraw(canvas);
        canvas.restore();
    }

    @Override
    public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
        invalidate();
        return super.invalidateChildInParent(location, dirty);
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent event) {
        viewTouchPoint[0] = event.getX();
        viewTouchPoint[1] = event.getY();
        rotateMatrix.mapPoints(childTouchPoint, viewTouchPoint);
        event.setLocation(childTouchPoint[0], childTouchPoint[1]);
        boolean result = super.dispatchTouchEvent(event);
        event.setLocation(viewTouchPoint[0], viewTouchPoint[1]);
        return result;
    }

}

main活动.java
public class MainActivity extends AppCompatActivity {

    MongolViewGroup viewGroup;
    EditText editText;
    int newWidth = 300;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        viewGroup = (MongolViewGroup) findViewById(R.id.viewGroup);
        editText = (EditText) findViewById(R.id.editText);
    }

    public void buttonClicked(View view) {

        newWidth += 200;
        ViewGroup.LayoutParams params = viewGroup.getLayoutParams();
        params.width=newWidth;
        viewGroup.setLayoutParams(params);
    }
}

活动\主.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.mongolviewgrouptest.MainActivity">

    <com.example.mongolviewgrouptest.MongolViewGroup
        android:id="@+id/viewGroup"
        android:layout_width="100dp"
        android:layout_height="200dp"
        android:background="@color/colorAccent">

        <EditText
            android:id="@+id/editText"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:textColor="@android:color/black"
            android:background="@android:color/white"/>

    </com.example.mongolviewgrouptest.MongolViewGroup>

    <Button
        android:text="Button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/button"
        android:onClick="buttonClicked"
        android:layout_alignParentTop="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"/>


</RelativeLayout>

最佳答案


再次调用viewgroup的viewRectRotated方法。
由于在您的viewgroups first layout之后onLayout(...)被设置为false(并且永远不会更改),那么计算edittext的angleChangedleftrighttop值的部分
在第一次查看组时跳过
请求布局(更改其高度或宽度时)。
因此,您的edittext仍然使用相同的bottomleftright
以及最初列出的值。
去掉top就可以了。就像这样:

@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
    final RectF layoutRect = tempRectF1;
    final RectF layoutRectRotated = tempRectF2;
    layoutRect.set(0, 0, right - left, bottom - top);
    rotateMatrix.setRotate(angle, layoutRect.centerX(), layoutRect.centerY());
    rotateMatrix.postScale(-1, 1);
    rotateMatrix.mapRect(layoutRectRotated, layoutRect);
    layoutRectRotated.round(viewRectRotated);
    final View view = getView();
    if (view != null) {
        view.layout(viewRectRotated.left, viewRectRotated.top, viewRectRotated.right,
                viewRectRotated.bottom);
    }
}

我已经测试过了,这样做很好。
如果您出于任何原因需要bottom,那么只需确保它在您的视图组的angleChanged方法中更改回angleChanged,以便再次重新计算true。不过,我不建议这么做。

10-07 19:15
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