6

我制作了这个自定义可绘制对象，它应该将任何可绘制对象剪成圆形。但是在我的实现中，传递的可绘制对象是原始形式的输出，而不是圆形形式的输出。

public class CircularDrawable extends Drawable {
    Paint mPaint,xfermodePaint;
    Drawable mDrawable;
    int[] vinylCenter = new int[2];
    int radius;
    Bitmap src;
    PorterDuffXfermode xfermode;
    Rect rect;
    Canvas testCanvas;
    public CircularDrawable(Drawable drawable) {
        mDrawable = drawable;
        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaint.setColor(0xffffffff);
        mPaint.setStyle(Paint.Style.FILL);
        xfermodePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        xfermode=new PorterDuffXfermode(PorterDuff.Mode.SRC_IN);
        xfermodePaint.setXfermode(xfermode);
        testCanvas=new Canvas();
    }

    @Override
    public void setBounds(Rect bounds) {
        super.setBounds(bounds);
        mDrawable.setBounds(bounds);
    }

    @Override
    public void setBounds(int left, int top, int right, int bottom) {
        super.setBounds(left, top, right, bottom);
        mDrawable.setBounds(left, top, right, bottom);
    }

    @Override
    protected void onBoundsChange(Rect bounds) {
        super.onBoundsChange(bounds);
        vinylCenter[0] = bounds.width() / 2;
        vinylCenter[1] = bounds.height() / 2;
        radius = (bounds.right - bounds.left) / 2;
        src = Bitmap.createBitmap(bounds.width(), bounds.height(), Bitmap.Config.ARGB_8888);
        testCanvas.setBitmap(src);
    }


    @Override
    public void draw(Canvas canvas) {
        canvas.save();
        canvas.drawARGB(0, 0, 0, 0);
        canvas.drawCircle(vinylCenter[0],vinylCenter[1],radius,mPaint);
        mDrawable.draw(testCanvas);
        canvas.drawBitmap(src,0f,0f,xfermodePaint);
    }



    @Override
    public void setAlpha(int alpha) {/*ignored*/}

    @Override
    public void setColorFilter(ColorFilter colorFilter) {/*ignored*/}

    @Override
    public int getOpacity() {
        /*ignored*/
        return 0;
    }
}

我的错误是什么？

此外，我正在使用 SquareImageview 来显示这个仅在 onMeasure 中使视图呈正方形的可绘制对象。这个问题不适用于圆形图像视图。

4

6 回答 6

4

您已经在支持库 v4 中优化了圆形可绘制对象的实现：

谷歌参考

 /**
* A Drawable that wraps a bitmap and can be drawn with rounded corners. You can create a
* RoundedBitmapDrawable from a file path, an input stream, or from a
* {@link android.graphics.Bitmap} object.
* <p>
* Also see the {@link android.graphics.Bitmap} class, which handles the management and
* transformation of raw bitmap graphics, and should be used when drawing to a
* {@link android.graphics.Canvas}.
* </p>
*/
public abstract class RoundedBitmapDrawable extends Drawable ....
于 2015-12-10T13:55:26.753 回答
3 
For circular imageview use the below code

public class RoundedImageView extends ImageView {

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

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

    public RoundedImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        BitmapDrawable drawable = (BitmapDrawable) getDrawable();

        if (drawable == null) {
            return;
        }

        if (getWidth() == 0 || getHeight() == 0) {
            return;
        }

        Bitmap fullSizeBitmap = drawable.getBitmap();

        int scaledWidth = getMeasuredWidth();
        int scaledHeight = getMeasuredHeight();

        /*
         * scaledWidth = scaledWidth/2; scaledHeight = scaledHeight/2;
         */

        Bitmap mScaledBitmap;
        if (scaledWidth == fullSizeBitmap.getWidth()
                && scaledHeight == fullSizeBitmap.getHeight()) {
            mScaledBitmap = fullSizeBitmap;
        } else {
            mScaledBitmap = Bitmap.createScaledBitmap(fullSizeBitmap,
                    scaledWidth, scaledHeight, true /* filter */);
        }

        // Bitmap roundBitmap = getRoundedCornerBitmap(mScaledBitmap);

        // Bitmap roundBitmap = getRoundedCornerBitmap(getContext(),
        // mScaledBitmap, 10, scaledWidth, scaledHeight, false, false,
        // false, false);
        // canvas.drawBitmap(roundBitmap, 0, 0, null);

        Bitmap circleBitmap = getCircledBitmap(mScaledBitmap);

        canvas.drawBitmap(circleBitmap, 0, 0, null);

    }

    public Bitmap getRoundedCornerBitmap(Context context, Bitmap input,
            int pixels, int w, int h, boolean squareTL, boolean squareTR,
            boolean squareBL, boolean squareBR) {

        Bitmap output = Bitmap.createBitmap(w, h, Config.ARGB_8888);
        Canvas canvas = new Canvas(output);
        final float densityMultiplier = context.getResources()
                .getDisplayMetrics().density;

        final int color = 0xff424242;

        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, w, h);
        final RectF rectF = new RectF(rect);

        // make sure that our rounded corner is scaled appropriately
        final float roundPx = pixels * densityMultiplier;

        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(color);
        canvas.drawRoundRect(rectF, roundPx, roundPx, paint);

        // draw rectangles over the corners we want to be square
        if (squareTL) {
            canvas.drawRect(0, 0, w / 2, h / 2, paint);
        }
        if (squareTR) {
            canvas.drawRect(w / 2, 0, w, h / 2, paint);
        }
        if (squareBL) {
            canvas.drawRect(0, h / 2, w / 2, h, paint);
        }
        if (squareBR) {
            canvas.drawRect(w / 2, h / 2, w, h, paint);
        }

        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(input, 0, 0, paint);

        return output;
    }

    Bitmap getCircledBitmap(Bitmap bitmap) {

        Bitmap result = Bitmap.createBitmap(bitmap.getWidth(),
                bitmap.getHeight(), Bitmap.Config.ARGB_8888);

        Canvas canvas = new Canvas(result);

        int color = Color.BLUE;
        Paint paint = new Paint();
        Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());

        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(color);
        // canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
        canvas.drawCircle(bitmap.getWidth() / 2, bitmap.getHeight() / 2,
                bitmap.getHeight() / 2, paint);

        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        canvas.drawBitmap(bitmap, rect, rect, paint);

        return result;
    }

}
于 2015-12-11T05:07:55.870 回答
3

所以基本上我使用这种方法来获得圆角图像

public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, int pixels) {
    Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(output);

    final int color = 0xff424242;
    final Paint paint = new Paint();
    final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
    final RectF rectF = new RectF(rect);
    final float roundPx = pixels;

    paint.setAntiAlias(true);
    canvas.drawARGB(0, 0, 0, 0);
    paint.setColor(color);
    canvas.drawRoundRect(rectF, roundPx, roundPx, paint);

    paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
    canvas.drawBitmap(bitmap, rect, rect, paint);

    return output;

但是就像您指出的那样，有时它不起作用，它确实起作用，但是大多数时候发生的情况是您的 imageview 可能将其 scaletype 设置为centerCrop和其他类型，我要做的是首先将图像高度压缩到相同的高度和宽度作为我的图像视图，以便整个图像适合图像视图并且不会发生缩放，或者我只是根据高度使用此函数计算要舍入多少角高度

   private int calculatePercentage(int percentage, int target)
{
    int k = (int)(target*(percentage/100.0f));
    return k;

}

所以我使用我的代码，例如：new Bitmap(getRoundedCornerBitmap(bmp, calculatePercentage(5, bmp.getHeight()))); where 5 is 5图像高度这给了我所有图像相同的曲线，如果有些图像比其他图像大`

于 2015-12-08T01:54:06.187 回答
3 
For rounded imageview you can use this code 

    public class RoundedImageView extends ImageView {

    public RoundedImageView(Context context) {
        super(context);
        // TODO Auto-generated constructor stub
    }

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

    public RoundedImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onDraw(Canvas canvas) {

        Drawable drawable = getDrawable();

        if (drawable == null) {
            return;
        }

        if (getWidth() == 0 || getHeight() == 0) {
            return;
        }
        Bitmap b = ((BitmapDrawable) drawable).getBitmap();
        Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);

        int w = getWidth();//, h = getHeight();

        Bitmap roundBitmap = getCroppedBitmap(bitmap, w);
        canvas.drawBitmap(roundBitmap, 0, 0, null);

    }

    public static Bitmap getCroppedBitmap(Bitmap bmp, int radius)
    {
        Bitmap sbmp;
        if (bmp.getWidth() != radius || bmp.getHeight() != radius)
            sbmp = Bitmap.createScaledBitmap(bmp, radius, radius, false);
        else
            sbmp = bmp;
        Bitmap output = Bitmap.createBitmap(sbmp.getWidth(), sbmp.getHeight(),Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

//      final int color = 0xffa19774;
        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, sbmp.getWidth(), sbmp.getHeight());

        paint.setAntiAlias(true);
        paint.setFilterBitmap(true);
        paint.setDither(true);
        canvas.drawARGB(0, 0, 0, 0);
//      paint.setColor(Color.parseColor("#BAB399"));
        paint.setColor(Color.parseColor("#FF0000"));
        canvas.drawCircle(sbmp.getWidth() / 2 + 0.7f, sbmp.getHeight() / 2 + 0.7f, sbmp.getWidth() / 2 + 0.1f, paint);
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        canvas.drawBitmap(sbmp, rect, rect, paint);

        return output;
    }
}
于 2015-12-09T11:00:03.560 回答
3

使用 Porter/Duff xfermode 模式时，画布默认没有 alpha 通道（根据我在 android 中的经验）。这就是整个图像（src）作为输出的原因。Porter/Duff xfermode 基于 Alpha 通道。

在 Circular Drawable 2 Canvas 的许多实现中，采用了 RGB 图像位图，而另一个仅给出了带有圆形遮罩的 alpha 通道位图。应用 Porter/Duff xfermode 并将结果绘制在主画布上。

我的错误是我没有指定在使用画布上的图层进行 xfermode 时要考虑 alpha 通道的绘图函数画布。

绘图功能将变为

@Override
public void draw(Canvas canvas) {
    int sc = canvas.saveLayer(null, null,
                    Canvas.HAS_ALPHA_LAYER_SAVE_FLAG |
                    );
    canvas.drawCircle(vinylCenter[0],vinylCenter[1],radius,mPaint);
    mDrawable.draw(testCanvas);
    canvas.drawBitmap(src,0f,0f,xfermodePaint);
    canvas.restoreToCount(sc);
}

保存图层以使用标志指示 alpha 通道，然后使用 xfermode。最后将其恢复到其保存计数。

于 2015-12-06T16:36:17.967 回答
0

如果您正在使用，请尝试禁用硬件加速PorterDuffXfermode：

在整个活动的清单中：

<activity android:hardwareAccelerated="false" />

或者在您使用 xfermode 的特定视图上：

myView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
于 2015-12-13T15:37:35.743 回答