超簡潔代碼實現CircleImageView
阿新 • • 發佈:2017-07-21
技術分享 length cti nds .config reset 緩存 類型 lines
效果圖:
頁面代碼:
public class CircleView extends ImageView {
private Paint mPaint = new Paint();
public CircleView(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onDraw(Canvas canvas) {
Drawable mDrawable = getDrawable();//獲取xml文件設置的圖片
if (null == mDrawable) super.onDraw(canvas);//假設為空,交給父類處理
Bitmap mBitmap = ((BitmapDrawable) mDrawable).getBitmap();//將圖片轉化成bitmap
int len = getWidth() < getHeight() ? getWidth() : getHeight();//獲取xml的長寬屬性值,選擇較小的
Bitmap tempBitmap = Bitmap.createBitmap(len, len, Bitmap.Config.ARGB_8888);//新建一個bitmap對象。作為緩存
Canvas mCanvas = new Canvas(tempBitmap);//新建畫布緩存bitmap對象
mPaint.setAntiAlias(true);//抗鋸齒
mCanvas.drawCircle(len / 2, len / 2, len / 2, mPaint);//畫一個圓
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));//設置畫筆的覆蓋類型
Matrix matrix = new Matrix(); // 初始化Matrix對象
matrix.setScale((float) len / mBitmap.getWidth(), (float) len / mBitmap.getHeight()); //設置縮放比例
mCanvas.drawBitmap(mBitmap, matrix, mPaint);//畫出縮放後的圖片
mPaint.reset();//重置畫筆
canvas.drawBitmap(tempBitmap, 0, 0, mPaint);//繪制緩存圖片
}
}
超簡潔代碼實現CircleImageView