android 圆角ImageView类，可设置弧度

 1 public class RoundImageView extends ImageView {
  2     private Paint paint;
  3     private int roundWidth = 50;
  4     private int roundHeight = 50;
  5     private Paint paint2;
  6 
  7     public RoundImageView(Context context, AttributeSet attrs, int defStyle) {
  8         super(context, attrs, defStyle);
  9         init(context, attrs);
 10     }
 11 
 12     public RoundImageView(Context context, AttributeSet attrs) {
 13         super(context, attrs);
 14         init(context, attrs);
 15     }
 16 
 17     public void SetRoundValue(float roundValue) {
 18         roundWidth = (int) roundValue;
 19         roundHeight = (int) roundValue;
 20     }
 21 
 22     public RoundImageView(Context context) {
 23         super(context);
 24         init(context, null);
 25     }
 26 
 27     @SuppressLint("Recycle")
 28     private void init(Context context, AttributeSet attrs) {
 29 
 30         if (attrs != null) {
 31             TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.RoundAngleImageView);
 32             roundWidth = a.getDimensionPixelSize(R.styleable.RoundAngleImageView_roundWidth, roundWidth);
 33             roundHeight = a.getDimensionPixelSize(R.styleable.RoundAngleImageView_roundHeight, roundHeight);
 34         } else {
 35             float density = context.getResources().getDisplayMetrics().density;
 36             roundWidth = (int) (roundWidth * density);
 37             roundHeight = (int) (roundHeight * density);
 38         }
 39 
 40         paint = new Paint();
 41         paint.setColor(Color.WHITE);
 42         paint.setAntiAlias(true);
 43         paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
 44 
 45         paint2 = new Paint();
 46         paint2.setXfermode(null);
 47     }
 48 
 49     @Override
 50     public void draw(Canvas canvas) {
 51         Bitmap bitmap = Bitmap.createBitmap(getWidth(), getHeight(), Config.ARGB_8888);
 52         Canvas canvas2 = new Canvas(bitmap);
 53         super.draw(canvas2);
 54         drawLiftUp(canvas2);
 55         drawRightUp(canvas2);
 56         drawLiftDown(canvas2);
 57         drawRightDown(canvas2);
 58         canvas.drawBitmap(bitmap, 0, 0, paint2);
 59         bitmap.recycle();
 60         bitmap = null;
 61     }
 62 
 63     private void drawLiftUp(Canvas canvas) {
 64         Path path = new Path();
 65         path.moveTo(0, roundHeight);
 66         path.lineTo(0, 0);
 67         path.lineTo(roundWidth, 0);
 68         path.arcTo(new RectF(0, 0, roundWidth * 2, roundHeight * 2), -90, -90);
 69         path.close();
 70         canvas.drawPath(path, paint);
 71     }
 72 
 73     private void drawLiftDown(Canvas canvas) {
 74         Path path = new Path();
 75         path.moveTo(0, getHeight() - roundHeight);
 76         path.lineTo(0, getHeight());
 77         path.lineTo(roundWidth, getHeight());
 78         path.arcTo(new RectF(0, getHeight() - roundHeight * 2, 0 + roundWidth * 2, getWidth()), 90, 90);
 79         path.close();
 80         canvas.drawPath(path, paint);
 81     }
 82 
 83     private void drawRightDown(Canvas canvas) {
 84         Path path = new Path();
 85         path.moveTo(getWidth() - roundWidth, getHeight());
 86         path.lineTo(getWidth(), getHeight());
 87         path.lineTo(getWidth(), getHeight() - roundHeight);
 88         path.arcTo(new RectF(getWidth() - roundWidth * 2, getHeight() - roundHeight * 2, getWidth(), getHeight()), 0,
 89                 90);
 90         path.close();
 91         canvas.drawPath(path, paint);
 92     }
 93 
 94     private void drawRightUp(Canvas canvas) {
 95         Path path = new Path();
 96         path.moveTo(getWidth(), roundHeight);
 97         path.lineTo(getWidth(), 0);
 98         path.lineTo(getWidth() - roundWidth, 0);
 99         path.arcTo(new RectF(getWidth() - roundWidth * 2, 0, getWidth(), 0 + roundHeight * 2), -90, 90);
100         path.close();
101         canvas.drawPath(path, paint);
102     }
103 
104 }