一行代码实现圆形头像

效果图

在开发APP中，经常要实现圆形头像，那么该如何实现呢？

要裁剪吗，要重写draw函数吗？不用，只用一行代码就可以实现

Glide实现圆形图像

Glide.with(mContext)
                .load(R.drawable.iv_image_header)
                .error(R.drawable.ic_error_default)
                .transform(new GlideCircleTransform(mContext))
                .into(mImage);

其中load后为载入的图像，error后为出错时载入的图像，transform是对其修改，我们也是通过这个GlideCirTransForm来修改的,使用的话要把mContext替换为你自己的activty，mImage为图片载入的位置

使用之前的准备

1.添加项目依赖

compile ‘org.greenrobot:eventbus:3.0.0‘
compile ‘com.squareup.retrofit2:retrofit:2.0.2‘
compile ‘com.squareup.retrofit2:converter-gson:2.0.2‘
compile ‘com.github.bumptech.glide:glide:3.7.0‘
compile ‘org.jetbrains:annotations-java5:15.0‘
compile ‘in.srain.cube:ultra-ptr:1.0.11‘
compile ‘com.wang.avi:library:1.0.5‘

2.导入GlideCircleTransform.java文件

GlideCircleTransform.java代码如下：

package com.sina.weibo.sdk.demo.utils;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Paint;

import com.bumptech.glide.load.engine.bitmap_recycle.BitmapPool;
import com.bumptech.glide.load.resource.bitmap.BitmapTransformation;

public class GlideCircleTransform extends BitmapTransformation {

    public GlideCircleTransform(Context context) {
        super(context);
    }

    @Override
    protected Bitmap transform(BitmapPool pool, Bitmap toTransform, int outWidth, int outHeight) {
        return circleCrop(pool, toTransform);
    }

    private static Bitmap circleCrop(BitmapPool pool, Bitmap source) {
        if (source == null) return null;

        int size = Math.min(source.getWidth(), source.getHeight());
        int x = (source.getWidth() - size) / 2;
        int y = (source.getHeight() - size) / 2;

        Bitmap squared = Bitmap.createBitmap(source, x, y, size, size);

        Bitmap result = pool.get(size, size, Bitmap.Config.ARGB_8888);
        if (result == null) {
            result = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888);
        }

        Canvas canvas = new Canvas(result);
        Paint paint = new Paint();
        paint.setShader(new BitmapShader(squared, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP));
        paint.setAntiAlias(true);
        float r = size / 2f;
        canvas.drawCircle(r, r, r, paint);
        return result;
    }

    @Override
    public String getId() {
        return getClass().getName();
    }
}

完成这两步，你就可以使用那行代码完成你自己的圆形头像啦！