RoundedBitmapDrawable 简单方式实现圆角图片

//开始写布局啦啦啦啦啦

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.example.apple.Custom.Matrix.DrawableActivity">

    <ImageView
        android:id="@+id/im_01"
        android:layout_width="150dp"
        android:layout_height="150dp" />

    <ImageView
        android:id="@+id/im_02"
        android:layout_width="150dp"
        android:layout_height="150dp" />

    <ImageView
        android:id="@+id/im_03"
        android:layout_width="150dp"
        android:layout_height="150dp" />

</LinearLayout>

  //初始化控件
  
  ImageView mm1 = (ImageView) findViewById(R.id.im_01);
  ImageView mm2 = (ImageView) findViewById(R.id.im_02);
  ImageView mm3 = (ImageView) findViewById(R.id.im_03);

  RoundedBitmapDrawable roundedBitmapDrawable1 = RoundedBitmapDrawableFactory.create(getResources(), BitmapFactory.decodeResource(getResources(), R.drawable.ns2));
  RoundedBitmapDrawable roundedBitmapDrawable2 = RoundedBitmapDrawableFactory.create(getResources(), BitmapFactory.decodeResource(getResources(), R.drawable.ns2));
  RoundedBitmapDrawable roundedBitmapDrawable3 = RoundedBitmapDrawableFactory.create(getResources(), BitmapFactory.decodeResource(getResources(), R.drawable.ns2));
  //设置为圆形
  roundedBitmapDrawable1.setCircular(true);
  mm1.setImageDrawable(roundedBitmapDrawable1);
  //设置圆角为150度
  roundedBitmapDrawable2.setCornerRadius(150);
  mm2.setImageDrawable(roundedBitmapDrawable2);
  //设置圆角为30度
  roundedBitmapDrawable3.setCornerRadius(30);
  mm3.setImageDrawable(roundedBitmapDrawable3);

//会发现女神脸变短了，谁干的，还我女神。。其实你去查看下源码不难发现这是由于系统通过矩阵对我们的图片进行了缩放处理，系统吧图片缩放成了正方形，所以图片就有了这种效果，解决办法有多种 
第一种，最简单的方法，上传图片的时候直接传正方形就ok，这个。。。有点鸡肋，这样处理非得把人累死。。我还想再活五百年 
第二种，不管你传的是啥，代码给你加工，不会累死你了，只是我会少活一年 囧 ，好,看大招

private Drawable createRoundImageWithBorder(Bitmap bitmap){
        //原图宽度
        int bitmapWidth = bitmap.getWidth();
        //原图高度
        int bitmapHeight = bitmap.getHeight();
        //边框宽度 pixel
        int borderWidthHalf = 20;

        //转换为正方形后的宽高
        int bitmapSquareWidth = Math.min(bitmapWidth,bitmapHeight);

        //最终图像的宽高
        int newBitmapSquareWidth = bitmapSquareWidth+borderWidthHalf;

        Bitmap roundedBitmap = Bitmap.createBitmap(newBitmapSquareWidth,newBitmapSquareWidth,Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(roundedBitmap);
        int x = borderWidthHalf + bitmapSquareWidth - bitmapWidth;
        int y = borderWidthHalf + bitmapSquareWidth - bitmapHeight;

        //裁剪后图像,注意X,Y要除以2 来进行一个中心裁剪
        canvas.drawBitmap(bitmap, x/2, y/2, null);
        Paint borderPaint = new Paint();
        borderPaint.setStyle(Paint.Style.STROKE);
        borderPaint.setStrokeWidth(borderWidthHalf);
        borderPaint.setColor(Color.WHITE);

        //添加边框
        canvas.drawCircle(canvas.getWidth()/2, canvas.getWidth()/2, newBitmapSquareWidth/2, borderPaint);

        RoundedBitmapDrawable roundedBitmapDrawable = RoundedBitmapDrawableFactory.create(getResources(),roundedBitmap);
        roundedBitmapDrawable.setGravity(Gravity.CENTER);
        roundedBitmapDrawable.setCircular(true);
        return roundedBitmapDrawable;
    }

https://blog.youkuaiyun.com/kiecool/article/details/78252071