我制作了这个自定义Drawable，它应该将任何Drawable夹在圆圈中。但在我的实现中，传递的drawable是原始形式的输出，而不是循环形式的输出
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;
}
}
我犯了什么错？
此外，我正在使用SquareImageview来显示这个可绘制的视图，它只会使视图在onMeasure中呈正方形。此问题不适用于Circular imageview。
您已经在支持库v4:中优化了循环可绘制的实现
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 ....
使用Porter/Duff xfermode模式时，画布默认不打开alpha通道（根据我在android中的经验）。这就是输出整个图像（src）的原因。Porter/Duff xfermode以Alpha频道为基础。
在许多Circular Drawable 2 Canvas的实现中，一个是给定的RGB图像位图，另一个是仅给定具有圆形掩码的alpha通道位图。Porter/Duff xfermodeis应用，结果绘制在主画布上。
我的错误是，我没有指定draw函数的画布，即在使用xfermode画布上的层时要考虑alpha通道。
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Layer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。
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;
但正如你所指出的，有时它不起作用，它确实起作用，但大多数时候发生的情况是，你的imageview可能将其scaletype设置为centerCrop和其他类型，我所做的是首先将我的图像高度压缩到与图像视图相同的高度和宽度，这样整个图像将适合图像视图，并且不会发生缩放，或者我只是根据高度计算使用该函数圆角的高度
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，比如：图像高度的new Bitmap(getRoundedCornerBitmap(bmp, calculatePercentage(5, bmp.getHeight()))); where 5 is 5，这给了我所有图像相同的曲线，即使有些图像比其他图像大`
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;
}
}
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;
}
}
如果使用PorterDuffXfermode:，请尝试禁用硬件加速
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);