Android 7.0文件共享

1.指定一个FileProvider

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.myapp">
    <application>
        <provider
            android:name="android.support.v4.content.FileProvider"
            //标识,建议用“${applicationId}.fileprovider”命名
            android:authorities="com.example.myapp.fileprovider" 
            android:grantUriPermissions="true"
            android:exported="false">
            <meta-data
                //文件共享目录,位于res/xml/目录下
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/filepaths" />
        </provider>  
    </application>
</manifest>

可以创建一个类继承v4包下的FileProvider:

/**
不用实现任何方法
*/
public class MyFileProvider extends FileProvider{
}

2.指定共享路径

在res/xml/目录下创建一个名为filepaths.xml的文件:

<paths> 
//path:要访问的路径
//name:名称,生成uri时使用
<files-path path = “images /” name = “myimages” /> 
</paths>

files-path指的是应用程序内部存储的目录,比如我们要获取该目录下名为default_image.jpg的文件,生成的uri为:

content://com.example.myapp.fileprovider/myimages/default_image.jpg

3.开始使用

调用系统相机拍照:

private Intent requestFileIntent;
File requestFile = new File(filePath);
requestFileIntent = new Intent(Intent.ACTION_VIEW);
requestFileIntent.setType("image/jpg");
//构造uri
Uri fileUri=FileProvider.getUriForFile(this,"com.example.myapp.fileprovider",requestFile);
//授予权限
requestFileIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
//保存位置
intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);
startActivityForResult(requestFileIntent, 0);

4.paths说明与目录对应关系:

1. 说明:

• path:目录名称,不能为空,可以为“.或者/”
• name:生成uri需要,不能为空

path是指当前目录下的子文件夹,“.“或者”/”时代表根目录,”images“代表该目录下 images文件夹

2.格式:

<paths xmlns：android = “http://schemas.android.com/apk/res/android” > 
    <files-path name = “my_images” path = “images /” />  
    <files-path name = “my_docs” path = “docs /” />  
</paths>

3. 对应关系:

命名	目录	说明	路径
<files-path/>	Context.getFilesDir()	应用内部存储目录	/data/data/<application package>/files
<cache-path/>	getCacheDir()	应用内部缓存目录	/data/data/<application package>/cache
<external-path/>	Environment.getExternalStorageDirectory()	外部存储目录	/sdcard/
<external-files-path/>	Context.getExternalFilesDir(String)	应用外部存储目录	SDCard/Android/data/<application package>/files/
<external-cache-path/>	Context.getExternalCacheDir()	应用外部缓存目录	SDCard/Android/data/<application package>/cache/
<external-media-path/>	Context.getExternalMediaDirs()	应用外部媒体目录(api>=21)

MIME Type 对照表

格式	mimetype
.3gp	video/3gpp
.apk	application/vnd.android.package-archive
.asf	video/x-ms-asf
.avi	video/x-msvideo
.bin	application/octet-stream
.bmp	image/bmp
.c	text/plain
.cla	application/octet-stream
.con	text/plain
.cpp	text/plain
.doc	application/msword
.doc	application/vnd.openxmlformats-officedocument.wordprocessingml.document
.xls	application/vnd.ms-excel
.xls	application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
.exe	application/octet-stream
.gif	image/gif
.gta	application/x-gtar
.gz	application/x-gzip
.h	text/plain
.htm	text/html
.htm	text/html
.jar	application/java-archive
.jav	text/plain
.jpe	image/jpeg
.jpg	image/jpeg
.js	application/x-javascript
.log	text/plain
.m3u	audio/x-mpegurl
.m4a	audio/mp4a-latm
.m4b	audio/mp4a-latm
.m4p	audio/mp4a-latm
.m4u	video/vnd.mpegurl
.m4v	video/x-m4v
.mov	video/quicktime
.mp2	audio/x-mpeg
.mp3	audio/x-mpeg
.mp4	video/mp4
.mpc	application/vnd.mpohun.certificate
.mpe	video/mpeg
.mpe	video/mpeg
.mpg	video/mpeg
.mpg	video/mp4
.mpg	audio/mpeg
.msg	application/vnd.ms-outlook
.ogg	audio/ogg
.pdf	application/pdf
.png	image/png
.pps	application/vnd.ms-powerpoint
.ppt	application/vnd.ms-powerpoint
.ppt	application/vnd.openxmlformats-officedocument.presentationml.presentation
.pro	text/plain
.rc	text/plain
.rmv	audio/x-pn-realaudio
.rtf	application/rtf
.sh	text/plain
.tar	application/x-tar
.tgz	application/x-compressed
.txt	text/plain
.wav	audio/x-wav
.wma	audio/x-ms-wma
.wmv	audio/x-ms-wmv
.wps	application/vnd.ms-works
.xml	text/plain
.z	application/x-compress
.zip	application/x-zip-compressed
" "	*/*

参考

1. https://developer.android.google.cn/training/secure-file-sharing/request-file
2. https://developer.android.google.cn/training/secure-file-sharing/share-file
3. https://developer.android.google.cn/reference/androidx/core/content/FileProvider.html