自记android学习小tips:继承并更改UIL的RoundedBitmapDisplayer，实现自定义圆角图片

本文链接：https://blog.youkuaiyun.com/lwlizhe/article/details/51637242

UIL虽然提供了绘制圆角矩形的方法，但是今天遇到一个问题，我想实现只有2个圆角的圆角矩形，但是UIL的RoundedBitmapDisplayer，自动完成是四个角的圆角矩形，所以只能自己重写方法来改变RoundedBitmapDisplayer。

重新更正下，其实自定义shape完全能达到需求……like this:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="#0099CC" />
    <corners android:bottomRightRadius="0dp"
        android:bottomLeftRadius="0dp"
        android:topRightRadius="20dp"
        android:topLeftRadius="20dp"/>
    <stroke android:width="1dp" android:color="#000000"/>
</shape>

下面那些又臭又长的代码就当做拓展算了……

代码如下：

public class HalfCircleImageViewDisplayer extends RoundedBitmapDisplayer {

    public HalfCircleImageViewDisplayer(int cornerRadiusPixels) {
        super(cornerRadiusPixels);
    }

    public HalfCircleImageViewDisplayer(int cornerRadiusPixels, int marginPixels) {
        super(cornerRadiusPixels, marginPixels);
    }

    @Override
    public void display(Bitmap bitmap, ImageAware imageAware, LoadedFrom loadedFrom) {
        if(!(imageAware instanceof ImageViewAware)) {
            throw new IllegalArgumentException("ImageAware should wrap ImageView. ImageViewAware is expected.");
        } else {
            imageAware.setImageDrawable(new HalfCircleImageViewDisplayer.RoundedDrawable(bitmap, this.cornerRadius, this.margin));
        }
    }

    public static class RoundedDrawable extends Drawable {
        protected final float cornerRadius;
        protected final int margin;
        protected final RectF mRect = new RectF();
        protected final RectF mBitmapRect;
        protected final BitmapShader bitmapShader;
        protected final Paint paint;
        protected final ShapeDrawable mDrawables;

        public RoundedDrawable(Bitmap bitmap, int cornerRadius, int margin) {
            this.cornerRadius = (float)cornerRadius;
            this.margin = margin;
            float[] outerR = new float[]{cornerRadius, cornerRadius, cornerRadius, cornerRadius, 0, 0, 0, 0};
            RoundRectShape rectShape = new RoundRectShape(outerR, null, null);
            this.mDrawables = new ShapeDrawable(rectShape);
            this.bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
            this.mDrawables.setBounds(margin, margin, (bitmap.getWidth() - margin), (bitmap.getHeight() - margin));
            this.mBitmapRect = new RectF((float)margin, (float)margin, (float)(bitmap.getWidth() - margin), (float)(bitmap.getHeight() - margin));
            this.paint = mDrawables.getPaint();
            this.paint.setAntiAlias(true);
            this.paint.setShader(this.bitmapShader);
        }

        protected void onBoundsChange(Rect bounds) {
            super.onBoundsChange(bounds);
            this.mRect.set((float)this.margin, (float)this.margin, (float)(bounds.width() - this.margin), (float)(bounds.height() - this.margin));
            Matrix shaderMatrix = new Matrix();
            shaderMatrix.setRectToRect(this.mBitmapRect, this.mRect, Matrix.ScaleToFit.FILL);
            this.bitmapShader.setLocalMatrix(shaderMatrix);
            this.mDrawables.setBounds(this.margin, this.margin, (bounds.width() - this.margin), (bounds.width() - this.margin));
        }

        public void draw(Canvas canvas) {
            mDrawables.draw(canvas);
//            canvas.drawRoundRect(this.mRect, this.cornerRadius, this.cornerRadius, this.paint);
        }

        public int getOpacity() {
            return -3;
        }

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

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


}