自定義圓角ImageVIew，支持加載網絡圖片

坑爹的UI出了一套列表效果圖，圖片要圓角顯示，在網上隨便找了圓角demo,加載本地圖片資源沒問題，但是當用xutils加載時，就蛋疼了，沒效果，去看了下demo里的源碼，2000多行，又是反射，又是雜七雜八的。干脆自己寫一個
直接上碼

package himan.xiao.yu.view;
import himan.xiao.yu.R;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.RectF;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;
/**

 * 圖片圓角實現，支持xUtils
 * 
 * @author Himan
 */
public class CustomImageView extends ImageView {
    private Paint paint;
    private Paint paintBorder;
    /** 圓角的幅度 **/
    private float mRadius;
    /** 是否是圓形 **/
    private boolean mIsCircle;
public CustomImageView(final Context context) {
    this(context, null);
}

public CustomImageView(Context context, AttributeSet attrs) {
    this(context, attrs, R.attr.customImageViewStyle);
}

public CustomImageView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    this.setScaleType(ScaleType.FIT_XY);
    // 獲取自定屬性配置
    TypedArray ta = context.obtainStyledAttributes(attrs,
            R.styleable.CustomImageView, defStyle, 0);
    mRadius = ta.getDimension(R.styleable.CustomImageView_radius, 0);
    mIsCircle = ta.getBoolean(R.styleable.CustomImageView_circle, false);
    ta.recycle();
    paint = new Paint();
    paint.setAntiAlias(true);
    paintBorder = new Paint();
    paintBorder.setAntiAlias(true);
}





@Override
public void onDraw(Canvas canvas) {
    // 去點padding值
    int width = canvas.getWidth() - getPaddingLeft() - getPaddingRight();
    int height = canvas.getHeight() - getPaddingTop() - getPaddingBottom();
    // 獲取iamgeView 中的drawable 并轉成bitmap
    Bitmap image = drawableToBitmap(getDrawable());
    // 對獲取到的bitmap 按照當前imageView的寬高進行縮放
    Bitmap reSizeImage = reSizeImage(image, width, height);
    // 判斷當前需要繪制圓角還是圓
    if (mIsCircle) {
        canvas.drawBitmap(createCircleImage(reSizeImage, width, height),
            getPaddingLeft(), getPaddingTop(), null);

} else {
    canvas.drawBitmap(createRoundImage(reSizeImage, width, height),
            getPaddingLeft(), getPaddingTop(), null);
}

}
/ 繪制圓角 /
private Bitmap createRoundImage(Bitmap source, int width, int height) {
    final Paint paint = new Paint();
    paint.setAntiAlias(true);
    Bitmap target = Bitmap.createBitmap(width, height, Config.ARGB_8888);
    Canvas canvas = new Canvas(target);
    RectF rect = new RectF(0, 0, width, height);
    canvas.drawRoundRect(rect, mRadius, mRadius, paint);
    // 關鍵代碼 設置畫筆的Mode 設置為獲取交集 
    paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
    canvas.drawBitmap(source, 0, 0, paint);
    return target;
}
private Bitmap createCircleImage(Bitmap source, int width, int height) {
    final Paint paint = new Paint();
    paint.setAntiAlias(true);
    Bitmap target = Bitmap.createBitmap(width, height, Config.ARGB_8888);
    Canvas canvas = new Canvas(target);
    canvas.drawCircle(width / 2, height / 2, Math.min(width, height) / 2,
            paint);
    paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
    canvas.drawBitmap(source, 0, 0, paint);
    return target;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    int width = MeasureSpec.getSize(widthMeasureSpec);
    int height = MeasureSpec.getSize(heightMeasureSpec);
    setMeasuredDimension(width, height);
}
/**

drawable轉bitmap

@param drawable
@return
*/
private Bitmap drawableToBitmap(Drawable drawable) {
 if (drawable == null) {
 return null;

 } else if (drawable instanceof BitmapDrawable) {
 return ((BitmapDrawable) drawable).getBitmap();

 }
 Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicHeight(),
     drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);

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

/**

重設Bitmap的寬高

@param bitmap
@param newWidth
@param newHeight
@return
*/
private Bitmap reSizeImage(Bitmap bitmap, int newWidth, int newHeight) {
 int width = bitmap.getWidth();
 int height = bitmap.getHeight();
 // 計算出縮放比
 float scaleWidth = ((float) newWidth) / width;
 float scaleHeight = ((float) newHeight) / height;
 // 矩陣縮放bitmap
 Matrix matrix = new Matrix();
 matrix.postScale(scaleWidth, scaleHeight);
 return Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);
 }

}</pre> 
attr中的resources


<declare-styleable name="Theme">
    <attr name="customImageViewStyle" format="reference" />
</declare-styleable>
<declare-styleable name="CustomImageView">
    <attr name="circle" format="boolean" />
    <attr name="radius" format="dimension" />
</declare-styleable>
 


源碼