Android实现圆角图片

<&＃63;xml version="1.0" encoding="utf-8"&＃63;>


  

  

  

public class MainActivity extends AppCompatActivity {

  private ImageView ivRectImg, ivCircleImg;

  private Bitmap bitmap;
  private int width;
  private int height;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    ivRectImg = findViewById(R.id.iv_rect_img);
    ivCircleImg = findViewById(R.id.iv_circle_img);

    bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.image_bg);
    width = bitmap.getWidth();
    height = bitmap.getHeight();

    rectRoundBitmap();
    circleBitmap();
  }

 // 圆角矩形
  private void rectRoundBitmap() {
    RoundedBitmapDrawable bitmapDrawable = RoundedBitmapDrawableFactory.create(getResources(), bitmap);
    bitmapDrawable.setAntiAlias(true);
    bitmapDrawable.setCornerRadius(50);
    ivRectImg.setImageDrawable(bitmapDrawable);
  }

  // 把bitmap图片进行剪切成正方形， 然后再设置圆角半径为正方形边长的一半即可
  private void circleBitmap() {
    Bitmap circle = null;
    int min = Math.min(width, height);
    int max = Math.max(width, height);
    if (width == height) {
      circle = Bitmap.createBitmap(bitmap, 0, 0, width, height);
    } else {
      // 居中裁剪
      if (width > height) {
        circle = Bitmap.createBitmap(bitmap, (max - min) / 2, 0, min, min);
      } else {
        circle = Bitmap.createBitmap(bitmap, 0, (max - min) / 2, min, min);
      }
    }
    RoundedBitmapDrawable bitmapDrawable = RoundedBitmapDrawableFactory.create(getResources(), circle);
    bitmapDrawable.setCornerRadius(min / 2);
    bitmapDrawable.setAntiAlias(true);
    ivCircleImg.setImageDrawable(bitmapDrawable);
  }
}