Android 使用Glide下载网络图片并加载

首先要在项目中集成一下Glide,在build.gradle如图：

implementation 'com.github.bumptech.glide:glide:3.7.0'

下载的工具类：

import android.content.Context;
import android.os.Environment;
import android.widget.Toast;

import com.bumptech.glide.Glide;
import com.bumptech.glide.request.animation.GlideAnimation;
import com.bumptech.glide.request.target.SimpleTarget;

import java.io.File;
import java.io.FileOutputStream;

public class SDFileHelper {

    private Context context;

    public SDFileHelper() {
    }

    public SDFileHelper(Context context) {
        super();
        this.context = context;
    }

    //Glide保存图片
    public void savePicture(final String fileName, String url){
        Glide.with(context).load(url).asBitmap().toBytes().into(new SimpleTarget<byte[]>() {
            @Override
            public void onResourceReady(byte[] bytes, GlideAnimation<? super byte[]> glideAnimation) {
                try {
                    savaFileToSD(fileName,bytes);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
    //往SD卡写入文件的方法
    public void savaFileToSD(String filename, byte[] bytes) throws Exception {
        //如果手机已插入sd卡,且app具有读写sd卡的权限
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            String filePath = Environment.getExternalStorageDirectory().getCanonicalPath()+"/budejie";
            File dir1 = new File(filePath);
            if (!dir1.exists()){
                dir1.mkdirs();
            }
            filename = filePath+ "/" + filename;
            //这里就不要用openFileOutput了,那个是往手机内存中写数据的
            FileOutputStream output = new FileOutputStream(filename);
            output.write(bytes);
            //将bytes写入到输出流中
            output.close();
            //关闭输出流
            Toast.makeText(context, "图片已成功保存到"+filePath, Toast.LENGTH_SHORT).show();
            SharePrefUtil.saveString(context,"filePath",filePath);
        } else Toast.makeText(context, "SD卡不存在或者不可读写", Toast.LENGTH_SHORT).show();
    }




}

使用：

SDFileHelper helper = new SDFileHelper(WxLoginActivity.this);
String url = "http://imgcache.qq.com/qzone/space_item/pre/0/66768.gif";
helper.savePicture("bg.jpg",url);
String filePath = SharePrefUtil.getString(WxLoginActivity.this,"filePath","")+"/bg.jpg";
 Glide
         .with(WxLoginActivity.this)
         .load(filePath)
         .placeholder(R.mipmap.ic_launcher) // can also be a drawable
         .into(mWxLogin);