创建RES / XML / filepaths.xml

 ＆LT; XML版本=1.0编码=UTF-8＆GT？;
＆LT;路径的xmlns：机器人=htt​​p://schemas.android.com/apk/res/android＆GT;
    ＆LT;缓存路径名=shared_images路径=图像//＆GT;
＆LT; /路径＆GT;
 

这告诉FileProvider何处获取文件共享（使用在这种情况下，高速缓存目录中）。

将图像保存到内部存储器

  //保存位图缓存目录
尝试 {

    文件cachePath =新的文件（context.getCacheDir（），图像）;
    cachePath.mkdirs（）; //不要忘了做目录
    的FileOutputStream流=新的FileOutputStream（cachePath +/image.png）; //每一次改写这个图片
    bitmap.com preSS（Bitmap.Com pressFormat.PNG，100，流）;
    stream.close（）;

}赶上（FileNotFoundException异常E）{
    e.printStackTrace（）;
}赶上（IOException异常E）{
    e.printStackTrace（）;
}
 

分享图片

 文件的ImagePath =新的文件（context.getCacheDir（），图像）;
文件NEWFILE =新的文件（的ImagePath，image.png）;
乌里contentUri = FileProvider.getUriForFile（背景下，com.example.app.fileprovider，NEWFILE）;

如果（contentUri！= NULL）{

    意图shareIntent =新意图（）;
    shareIntent.setAction（Intent.ACTION_SEND）;
    shareIntent.addFlags（Intent.FLAG_GRANT_READ_URI_PERMISSION）; //用于接收应用程序读取该文件的临时许可
    shareIntent.setDataAndType（contentUri，getContentResolver（）的getType（contentUri））;
    shareIntent.putExtra（Intent.EXTRA_STREAM，contentUri）;
    startActivity（Intent.createChooser（shareIntent，选择一个应用程序））;

}
 

进一步阅读

I try to export a bitmap from my app using share intent without saving a file for a temporal location. All the examples I found are two-step 1) save to SD Card and create Uri for that file 2) start the intent with this Uri

Is it possible to make it without requiring WRITE_EXTERNAL_STORAGE permission, saving the file [and removing it afterwards]? How to address devices without ExternalStorage?

I had this same problem. I didn't want to have to ask for the read and write external storage permissions. Also, sometimes there are problems when phones don't have SD cards or the cards get unmounted.

The following method uses a ContentProvider called FileProvider. Technically, you are still saving the bitmap (in internal storage) prior to sharing, but you don't need to request any permissions. Also, every time you share the bitmap the image file gets overwritten. And since it is in the internal cache, it will be deleted when the user uninstalls the app. So in my opinion, it is just as good as not saving the image. This method is also more secure than saving it to external storage.

The documentation is pretty good (see the Further Reading below), but some parts are a little tricky. Here is a summary that worked for me.

Set up the FileProvider in the Manifest

<manifest>
    ...
    <application>
        ...
        <provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="com.example.myapp.fileprovider"
            android:grantUriPermissions="true"
            android:exported="false">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/filepaths" />
        </provider>
        ...
    </application>
</manifest>

Replace com.example.myapp with your app package name.

Create res/xml/filepaths.xml

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <cache-path name="shared_images" path="images/"/>
</paths>

This tells the FileProvider where to get the files to share (using the cache directory in this case).

Save the image to internal storage

// save bitmap to cache directory
try {

    File cachePath = new File(context.getCacheDir(), "images");
    cachePath.mkdirs(); // don't forget to make the directory
    FileOutputStream stream = new FileOutputStream(cachePath + "/image.png"); // overwrites this image every time
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
    stream.close();

} catch (FileNotFoundException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
}

Share the image

File imagePath = new File(context.getCacheDir(), "images");
File newFile = new File(imagePath, "image.png");
Uri contentUri = FileProvider.getUriForFile(context, "com.example.app.fileprovider", newFile);

if (contentUri != null) {

    Intent shareIntent = new Intent();
    shareIntent.setAction(Intent.ACTION_SEND);
    shareIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION); // temp permission for receiving app to read this file
    shareIntent.setDataAndType(contentUri, getContentResolver().getType(contentUri));
    shareIntent.putExtra(Intent.EXTRA_STREAM, contentUri);
    startActivity(Intent.createChooser(shareIntent, "Choose an app"));

}

Further reading