Android程序设计-圆形图片的实现

在android中，google只提供了对图形的圆形操作，而没有实现对图片的圆形操作，所以我们无法实现上述操作，在此我们将使用框架进行设计（下述框架为as编写）：

https://github.com/monsterLin/RoundedImageView

https://github.com/pungrue26/SelectableRoundedImageView
https://github.com/hdodenhof/CircleImageView
https://github.com/MostafaGazar/CustomShapeImageView
https://github.com/siyamed/android-shape-imageview

下面我们通过使用RoundedImageView来是实现这种效果：

首先我们在项目中导入开源框架：

导入成功后-

第一种方式：直接书写xml文件：

<com.makeramen.roundedimageview.RoundedImageView
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/imageView1"
        android:layout_width="40dp"
        android:layout_height="40dp"
        android:src="@drawable/photo"
        app:riv_corner_radius="30dip"
        app:riv_border_width="2dip"
        app:riv_border_color="#333333"
        app:riv_mutate_background="true"
        app:riv_oval="true" />

第二种方式：通过代码实现：

public static class RoundedDrawable extends Drawable {

        protected final float cornerRadius;
        protected final int margin;

        protected final RectF mRect = new RectF(),
                mBitmapRect;
        protected final BitmapShader bitmapShader;
        protected final Paint paint;

        public RoundedDrawable(Bitmap bitmap, int cornerRadius, int margin) {
            this.cornerRadius = cornerRadius;
            this.margin = margin;

            bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
            mBitmapRect = new RectF (margin, margin, bitmap.getWidth() - margin, bitmap.getHeight() - margin);
            
            paint = new Paint();
            paint.setAntiAlias(true);
            paint.setShader(bitmapShader);
        }

        @Override
        protected void onBoundsChange(Rect bounds) {
            super.onBoundsChange(bounds);
            mRect.set(margin, margin, bounds.width() - margin, bounds.height() - margin);
            
            // Resize the original bitmap to fit the new bound
            Matrix shaderMatrix = new Matrix();
            shaderMatrix.setRectToRect(mBitmapRect, mRect, Matrix.ScaleToFit.FILL);
            bitmapShader.setLocalMatrix(shaderMatrix);
            
        }

        @Override
        public void draw(Canvas canvas) {
            canvas.drawRoundRect(mRect, cornerRadius, cornerRadius, paint);
        }

        @Override
        public int getOpacity() {
            return PixelFormat.TRANSLUCENT;
        }

        @Override
        public void setAlpha(int alpha) {
            paint.setAlpha(alpha);
        }

        @Override
        public void setColorFilter(ColorFilter cf) {
            paint.setColorFilter(cf);
        }
    }



imageAware.setImageDrawable(new RoundedDrawable(bitmap, cornerRadius, margin));

附录：

eclipse的开源框架：http://files.cnblogs.com/files/boy1025/roundedimageview.zip