Android CircleImageView simple code

Android wants to use the ImageView circular image of avatar , you can define a CircleImageView to inherit the ImageView class, or use the Glide framework to load the ImageView circular image. The two forms are introduced below.

Method 1: Define CircleImageView, inherit the ImageView class

package com.android.presentation.app;

import android.annotation.Nullable;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Shader;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;


/**
 * desc：A simple and efficient circle image
 *
 */
public class CircleImageView extends ImageView {
    private float width;
    private float height;
    private float radius;
    private Paint paint;
    private Matrix matrix;

    public CircleImageView(Context context) {
        this(context, null);
    }

    public CircleImageView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public CircleImageView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        paint = new Paint();
        paint.setAntiAlias(true);   
        matrix = new Matrix();      
    }

    /**
     * 测量控件的宽高，并获取其内切圆的半径
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        width = getMeasuredWidth();
        height = getMeasuredHeight();
        radius = Math.min(width, height) / 2;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        Drawable drawable = getDrawable();
        if (drawable == null) {
            super.onDraw(canvas);
            return;
        }
        if (drawable instanceof BitmapDrawable) {
            BitmapShader bitmapShader = initBitmapShader((BitmapDrawable) drawable);
            if(bitmapShader!=null)
            {
                paint.setShader(bitmapShader);//将着色器设置给画笔
                canvas.drawCircle(width / 2, height / 2, radius, paint);
            }
            return;
        }
        super.onDraw(canvas);
    }

    /**
     * get bitmap from Imageview
     */
    private BitmapShader initBitmapShader(BitmapDrawable drawable) {
        Bitmap bitmap = drawable.getBitmap();
        if(bitmap==null)
        {
            return null;
        }
        BitmapShader bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
        float scale = Math.max(width / bitmap.getWidth(), height / bitmap.getHeight());
        matrix.setScale(scale, scale);
        bitmapShader.setLocalMatrix(matrix);
        return bitmapShader;
    }
}

use CircleImageView in xml

<com.android.presentation.app.CircleImageView
   android:layout_width="100px"
   android:layout_height="100px"
   android:scaleType="fitXY"
   android:layout_marginLeft="100px"
   android:layout_marginTop="100px"
   android:src="@drawable/aiqing"/>

Method 2: Use the Glide framework to load the circular avatar image

Glide.with(mContext)
.load(R.drawable.aiqing)
.apply(RequestOptions.circleCropTransform())
.into(headImg);

The effect as follow: