我有一个Android应用程序，允许用户如下选择个人资料照片：
public void pickImage(View view) {
Intent getIntent = new Intent(Intent.ACTION_GET_CONTENT);
getIntent.setType("image/*");
Intent pickIntent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
pickIntent.setType("image/*");
Intent chooserIntent = Intent.createChooser(getIntent, "Select Image");
chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Intent[] {pickIntent});
startActivityForResult(chooserIntent, 1);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
Context context = getApplicationContext();
if (requestCode == 1 && resultCode == Activity.RESULT_OK) {
if (data == null) {
//Display an error
return;
}
try {
ImageView im = findViewById(R.id.circularImageView);
uri = data.getData();
im.setImageURI(uri);
String image = uri.toString();
Log.d("ImageS", image);
SqlHelper db = new SqlHelper(this);
Intent i = getIntent();
String userid = i.getStringExtra("Name");
db.updateImage(userid, image);
}catch (Exception e){
}
//Now you can do whatever you want with your inpustream, save it as file, upload to a server, decode a bitmap...
}
}
在重新启动应用程序之前，一切正常。在这里，我想从数据库中检索图像，一切正常：
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ActionBar actionBar = getActionBar();
actionBar.hide();
setContentView(R.layout.activity_main);
String[] permissions = {Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.MANAGE_DOCUMENTS};
for(String permission: permissions){
if (ContextCompat.checkSelfPermission(this, permission)
!= PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
permission)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
} else {
// No explanation needed; request the permission
ActivityCompat.requestPermissions(this,
permissions, 0);
// MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
// app-defined int constant. The callback method gets the
// result of the request.
}
}
}
mGoogleApiClient = new GoogleApiClient.Builder(this).addApi(LocationServices.API).addConnectionCallbacks(this).addOnConnectionFailedListener(this).build();
ImageView logo = findViewById(R.id.imageView4);
logo.setImageResource(R.drawable.logo);
SqlHelper db = new SqlHelper(this);
//Add some locations for the users
a.setLatitude(Latitude[0]);
a.setLongitude(Longitude[0]);
b.setLatitude(Latitude[1]);
b.setLongitude(Longitude[1]);
Intent intentR = getIntent();
String name = intentR.getStringExtra("Name");
// Check for the freshest data.
ImageView im1 = findViewById(R.id.circularImageView2);
im1.setImageURI(null);
String iS = db.getImage(name);
Log.d("ImageR", iS);
//
// Uri uri = Uri.parse(image);
//Log.d("Equals", String.valueOf(iS.equals(String.valueOf(R.drawable.imageuser))));
if(iS.equals(String.valueOf(R.drawable.imageuser))){
im1.setImageResource(Integer.parseInt(iS));
}else{
Uri uri = Uri.parse(iS);
ContentResolver contentResolver= getContentResolver();
ParcelFileDescriptor parcelFileDescriptor = null;
try {
//HERE COMES THE PROBLEM//
parcelFileDescriptor = contentResolver.openFileDescriptor(uri, "r"); /
} catch (FileNotFoundException e) {
e.printStackTrace();
}
FileDescriptor fileDescriptor = parcelFileDescriptor.getFileDescriptor();
Bitmap image = BitmapFactory.decodeFileDescriptor(fileDescriptor);
try {
parcelFileDescriptor.close();
} catch (IOException e) {
e.printStackTrace();
}
im1.setImageBitmap(image);
}
ArrayList<String> notifications = db.getNotifications(name);
if(notifications.size()>0) {
ImageView im = findViewById(R.id.bell);
ImageView c = findViewById(R.id.circleN);
TextView tx = findViewById(R.id.nNot);
im.setVisibility(View.VISIBLE);
c.setVisibility(View.VISIBLE);
tx.setVisibility(View.VISIBLE);
tx.setText(String.valueOf(notifications.size()));
}
// db.addUser(new User("Babouche", "Babouche", location[1]), this);
// db.addUser(new User("Arturo", "Arturo", location[0]), this);
}`
问题是，当我重新启动应用程序时，进入用户更改图像的活动时，出现以下错误：
FATAL EXCEPTION: main
Process: com.example.arturopavon.finalproject, PID: 1445
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.arturopavon.finalproject/com.example.arturopavon.finalproject.MainActivity} : java.lang.SecurityException: Permission Denial: opening provider com.android.providers.media.MediaDocumentsProvider from ProcessRecord{47cb71a 1445:com.example.arturopavon.finalproject/u0a294} (pid=1445, uid=10294) requires that you obtain access using ACTION_OPEN_DOCUMENT or related APIs
我已经为我的应用设置了读取内部存储的权限，但是重启后好像无法使用。
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.arturopavon.finalproject">
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission
android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission
android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission
android:name="android.permission.MANAGE_DOCUMENTS"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="BiteME"
android:roundIcon="@drawable/logo"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".LoginActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".MainActivity" />
<activity android:name=".UserActivity" />
<activity android:name=".UserPreferences" />
<activity android:name=".SignUp" />
<activity android:name=".Notifications" />
</application>
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.login);
String[] permissions = {Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.MANAGE_DOCUMENTS};
for(String permission: permissions){
if (ContextCompat.checkSelfPermission(this, permission)
!= PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
permission)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
} else {
// No explanation needed; request the permission
ActivityCompat.requestPermissions(this,
permissions, 0);
// MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
// app-defined int constant. The callback method gets the
// result of the request.
}
}
}
}
关于如何解决这个问题的任何想法？
参考方案
如SAF Storage Access Framework (SAF)中所述：
如果您希望您的应用仅读取/导入数据，请使用ACTION_GET_CONTENT。通过这种方法，应用程序可以导入数据的副本，例如图像文件。
如果您希望您的应用对文件提供者拥有的文件具有长期，持久的访问权限，请使用ACTION_OPEN_DOCUMENT。
看来您有第二个用例。
所以代替：Intent getIntent = new Intent(Intent.ACTION_GET_CONTENT);
尝试Intent getIntent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
该文档提供了一个sample来使用它。
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