原理 一 整体代码再后面
github地址：（完整demo，欢迎下载）
https://github.com/zhouxu88/SaveImgToGallery/tree/master
Adnroid中保存图片的方法可能有如下两种：
第一种是调用系统提供的插入图库的方法：
MediaStore.Images.Media.insertImage(getContentResolver(), bitmap, "title", "description");
调用以上系统自带的方法会把bitmap对象保存到系统图库中，但是这种方法无法指定保存的路径和名称，上述方法的title、description参数只是插入数据库中的字段，真实的图片名称系统会自动分配。
或者
MediaStore.Images.Media.insertImage(getContentResolver(), "image path", "title", "description");
但是发现，还是不能在相册中查看已经保存到的图片，结果发现需要刷新系统图库
更新系统图库的方法
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://"+ Environment.getExternalStorageDirectory())));上面那条广播是扫描整个sd卡的广播，如果你sd卡里面东西很多会扫描很久，在扫描当中我们是不能访问sd卡，所以这样子用户体现很不好，所以下面我们还有如下的方法：
sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(new File("your path"))););完整代码
1、保存Bitmap到本地指定路径下
2、通过广播，通知系统相册图库刷新数据
public class ImgUtils { //保存文件到指定路径
public static boolean saveImageToGallery(Context context, Bitmap bmp) { // 首先保存图片
String storePath = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "dearxy";
File appDir = new File(storePath); if (!appDir.exists()) {
appDir.mkdir();
}
String fileName = System.currentTimeMillis() + ".jpg";
File file = new File(appDir, fileName); try {
FileOutputStream fos = new FileOutputStream(file); //通过io流的方式来压缩保存图片
boolean isSuccess = bmp.compress(Bitmap.CompressFormat.JPEG, 60, fos);
fos.flush();
fos.close(); //把文件插入到系统图库
//MediaStore.Images.Media.insertImage(context.getContentResolver(), file.getAbsolutePath(), fileName, null);
//保存图片后发送广播通知更新数据库
Uri uri = Uri.fromFile(file);
context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, uri)); if (isSuccess) { return true;
} else { return false;
}
} catch (IOException e) {
e.printStackTrace();
} return false;
}
}注意：
1、别忘了权限
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
2、如果是6.0手机，记得先申请权限，拿到权限后，再保存，不然会失败，我就是在这里被坑了
作者：唠嗑008
链接：https://www.jianshu.com/p/8cede074ba5b
來源：简书
简书著作权归作者所有，任何形式的转载都请联系作者获得授权并注明出处。
整体代码
下载类，可以url下载，也可以本地的drawable下载到相册，记得在清单加权限，6.0代码动态加权限判断，下载图片要在子线程中下载，下载完后广播更新相册
代码下载地址：链接：https://pan.baidu.com/s/1dsjx2QCSw2SxRcUW0Z3Xqg
提取码：i8j2
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
package com.example.administrator.myimageload;
/**
* Created by Administrator on 2018/9/17.
*/
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.provider.MediaStore;
import android.text.TextUtils;
import android.util.Log;
import android.widget.Toast;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.UUID;
/**
* Created by vimi8 on 2017/6/9.
*/
public class ImgDonwloads {
private static String filePath;
private static Bitmap mBitmap;
private static String mFileName="sshs";
private static String mSaveMessage;
private final static String TAG = "ImageActivity";
private static Context context;
private static ProgressDialog mSaveDialog = null;
public static void donwloadImg(Context contexts,String filePaths){
context = contexts;
filePath = filePaths;
mSaveDialog = ProgressDialog.show(context, "保存二维码", "二维码图片正在保存中，请稍等...", true);
new Thread(saveFileRunnable).start();
}
private static Runnable saveFileRunnable = new Runnable(){
@Override
public void run() {
try {
// mBitmap = BitmapFactory.decodeStream(getImageStream(filePath));
if (!TextUtils.isEmpty(filePath)) { //网络图片
//对资源链接
URL url=new URL(filePath);
//打开输入流
InputStream inputStream=url.openStream();
//对网上资源进行下载转换位图图片
mBitmap= BitmapFactory.decodeStream(inputStream);
inputStream.close();
}
Bitmap bmp = BitmapFactory.decodeResource(context.getResources(),R.drawable.bg_guid_1 ); //本地的图片，根据自己情况
// saveFile(mBitmap, mFileName);
saveFile(bmp);
mSaveMessage = "图片保存成功！";
} catch (IOException e) {
mSaveMessage = "图片保存失败！";
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
messageHandler.sendMessage(messageHandler.obtainMessage());
}
};
private static Handler messageHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
mSaveDialog.dismiss();
Log.d(TAG, mSaveMessage);
Toast.makeText(context, mSaveMessage, Toast.LENGTH_SHORT).show();
}
};
/**
* Get image from newwork
* @param path The path of image
* @return InputStream
* @throws Exception
*/
public static InputStream getImageStream(String path) throws Exception{
URL url = new URL(path);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setConnectTimeout(5 * 1000);
conn.setRequestMethod("GET");
if(conn.getResponseCode() == HttpURLConnection.HTTP_OK){
return conn.getInputStream();
}
return null;
}
/**
* 保存文件
* @param bm
* @param fileName
* @throws IOException
*/
public static void saveFile(Bitmap bm, String fileName) throws IOException {
File dirFile = new File(Environment.getExternalStorageDirectory().getPath());
if(!dirFile.exists()){
dirFile.mkdir();
}
fileName = UUID.randomUUID().toString()+".jpg";
File myCaptureFile = new File(Environment.getExternalStorageDirectory().getPath() +"/DCIM/Camera/"+ fileName);
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(myCaptureFile));
bm.compress(Bitmap.CompressFormat.JPEG, 80, bos);
bos.flush();
bos.close();
//把图片保存后声明这个广播事件通知系统相册有新图片到来
Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
Uri uri = Uri.fromFile(myCaptureFile);
intent.setData(uri);
context.sendBroadcast(intent);
}
/**
* 保存图片到图库
* @param bmp
*/
public static void saveFile( Bitmap bmp) {
// 首先保存图片
File appDir = new File(Environment.getExternalStorageDirectory(),
"sshs");
if (!appDir.exists()) {
appDir.mkdir();
}
String fileName = System.currentTimeMillis() + ".jpg";
File file = new File(appDir, fileName);
try {
FileOutputStream fos = new FileOutputStream(file);
bmp.compress(Bitmap.CompressFormat.JPEG, 80, fos);
fos.flush();
fos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// 其次把文件插入到系统图库
try {
MediaStore.Images.Media.insertImage(context.getContentResolver(),
file.getAbsolutePath(), fileName, null);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
// 最后通知图库更新
context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE,
Uri.fromFile(new File(file.getPath()))));
}
}
MainActivity类
public class MainActivity extends AppCompatActivity {
private Bitmap bitmap;
private TextView tv ;
String iPath = "http://i.imgur.com/DvpvklR.png";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv = (TextView) findViewById(R.id.tv);
// download() ;
tv.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
List<String> permissionList = new ArrayList<>();
if (ContextCompat.checkSelfPermission(MainActivity.this,
Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
permissionList.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
}
if (!permissionList.isEmpty()) {
String[] permissions = permissionList.toArray(new String[permissionList.size()]);
ActivityCompat.requestPermissions(MainActivity.this, permissions, 1);
} else {
ImgDonwloads.donwloadImg(MainActivity.this,"");//iPath
}
}
});
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
switch (requestCode) {
case 1:
if (grantResults.length > 0) {
for (int result : grantResults) {
if (result != PackageManager.PERMISSION_GRANTED) {
Toast.makeText(this, "拒绝了权限", Toast.LENGTH_SHORT).show();
// finish();
return;
}
}
ImgDonwloads.donwloadImg(MainActivity.this,"");
} else {
Toast.makeText(this, "发生未知错误", Toast.LENGTH_SHORT).show();
// finish();
}
break;
default:
}
}
}
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作者：code_dream_wq
来源：CSDN
原文：https://blog.csdn.net/code_dream_wq/article/details/82771800
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