Corners ImgeView适合在CardView内部没有半径像CardView在Android中的角落

我正在开发一个 Android应用程序.在我的应用程序中,我一起使用CardView和ImageView.但我在设计CardView内部的ImageView时遇到了问题.问题在于ImageView的圆角半径半径.请参阅下面的我的场景.

I have xml layout for adapter item like this.

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_marginTop="5dp"
    android:layout_marginLeft="5dp"
    android:layout_marginRight="5dp"
    card_view:cardCornerRadius="5dp"
    android:layout_width="match_parent"
    android:id="@+id/di_card_container"
    android:layout_height="wrap_content">

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <ImageView
            android:id="@+id/di_iv_image"
            android:scaleType="centerCrop"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

        <RelativeLayout
            android:padding="10dp"
            android:layout_below="@id/di_iv_image"
            android:layout_alignParentLeft="true"
            android:layout_alignParentBottom="true"
            android:id="@+id/di_name_container"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">
            <TextView
                android:textSize="15dp"
                android:textColor="@color/textColorPrimary"
                android:id="@+id/di_tv_name"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" />
        </RelativeLayout>
    </RelativeLayout>
</android.support.v7.widget.CardView>

正如您所看到的那样,我将CardView的圆角半径设置为5dp,而ImageView with则适合其父CardView的宽度.问题是ImageView的顶角不像其父CardView的角落那样弯曲.

This is the screenshot

通常,CardView的子视图角会自动弯曲,如果它适合父CardView.对？那么为什么我的ImageView不工作？请问我的代码有什么问题？我该怎么办呢？

解决方法

所以这是前棒棒糖的常见行为.以下是修复它的步骤：

第1步：将以下属性添加到您的cardView

card_view:cardUseCompatPadding="true"
card_view:cardPreventCornerOverlap="false"
card_view:cardCornerRadius="10dp"

第2步：使用围绕其顶部边框的自定义ImageView：

public class RoundedTopImageView extends ImageView {
private Paint                       mPaint;
private Path                        mPath;
private Bitmap                      mBitmap;
private Matrix                      mMatrix;
private int                         mRadius = displayUtils.convertDpToPixel(10);
private int                         mWidth;
private int                         mHeight;
private Drawable                    mDrawable;

public RoundedTopImageView(Context context) {
    super(context);
    init();
}

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

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

private void init() {
    mPaint = new Paint();
    mPaint.setColor(Color.WHITE);

    mPath = new Path();
}

@Override
public void setimageDrawable(Drawable drawable) {
    mDrawable = drawable;
    if (drawable == null) {
        return;
    }
    mBitmap = drawabletoBitmap(drawable);

    int bDIWidth = mBitmap.getWidth();
    int bDIHeight = mBitmap.getHeight();

    //Fit to screen.
    float scale;
    if ((mHeight / (float)bDIHeight) >= (mWidth / (float)bDIWidth)){
        scale =  mHeight / (float)bDIHeight;
    } else {
        scale = mWidth / (float)bDIWidth;
    }

    float borderLeft = (mWidth - (bDIWidth * scale)) / 2;
    float borderTop = (mHeight - (bDIHeight * scale)) / 2;

    mMatrix = getimageMatrix();
    RectF drawableRect = new RectF(0,bDIWidth,bDIHeight);
    RectF viewRect = new RectF(borderLeft,borderTop,(bDIWidth * scale) + borderLeft,(bDIHeight * scale) + borderTop);
    mMatrix.setRectToRect(drawableRect,viewRect,Matrix.ScaletoFit.CENTER);
    invalidate();
}

private Bitmap drawabletoBitmap(Drawable drawable) {
    Bitmap bitmap;

    if (drawable instanceof BitmapDrawable) {
        BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
        if(bitmapDrawable.getBitmap() != null) {
            return bitmapDrawable.getBitmap();
        }
    }

    if(drawable.getIntrinsicWidth() <= 0 || drawable.getIntrinsicHeight() <= 0) {
        bitmap = Bitmap.createBitmap(1,1,Bitmap.Config.ARGB_8888); // Single color bitmap will be created of 1x1 pixel
    } else {
        bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(),drawable.getIntrinsicHeight(),Bitmap.Config.ARGB_8888);
    }

    Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0,canvas.getWidth(),canvas.getHeight());
    drawable.draw(canvas);
    return bitmap;
}

@Override
protected void onMeasure(int widthMeasureSpec,int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec,heightMeasureSpec);
    mWidth = MeasureSpec.getSize(widthMeasureSpec);
    mHeight = MeasureSpec.getSize(heightMeasureSpec);
    if ((mDrawable != null) && (mHeight > 0) && (mWidth > 0)) {
        setimageDrawable(mDrawable);
    }
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);

    if (mBitmap == null) {
        return;
    }

    canvas.drawColor(Color.TRANSPARENT);

    mPath.reset();
    mPath.moveto(0,mRadius);
    mPath.lineto(0,canvas.getHeight());
    mPath.lineto(canvas.getWidth(),mRadius);
    mPath.quadTo(canvas.getWidth(),canvas.getWidth() - mRadius,0);
    mPath.lineto(mRadius,0);
    mPath.quadTo(0,mRadius);


    canvas.drawPath(mPath,mPaint);
    canvas.clipPath(mPath);
    canvas.drawBitmap(mBitmap,mMatrix,mPaint);
}

}

第3步：只需使用RoundedTopImageView替换xml中的ImageView

第4步：在代码中将其用作常规imageView,例如使用Picasso：

RoundedTopImageView image = (RoundedTopImageView) findViewById(R.id.di_iv_image);
Picasso.with(context)
                    .load("Some cool Url")
                    .into(image);

编辑：添加了convertDpToPixel函数

抱歉,我忘了添加这个,这是一个Util类的一部分,你可以在任何你想要的地方添加(在我的displayUtils类中)：

public static int convertDpToPixel(int dp) {
    displayMetrics displayMetrics = Resources.getSystem().getdisplayMetrics();
    return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,dp,displayMetrics);
}