<intent-filter>getIntent()獲取action、數(shù)據(jù)，并進行處理FileProvider完成<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myapp">
<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><meta-data>指定描述要分享的目錄的xml文件<paths>
<files-path path="images/" name="myimages" />
</paths><paths>標簽可以有多個子標簽，<files-path>指定app的files目錄下的分享目錄名，<external-path>指定外部存儲（Environment.getExternalStorageDirectory()）的分享目錄名，<cache-path>指定app的cache目錄下的分享目錄名；分享路徑只能在xml中描述；content://com.example.myapp.fileprovider/myimages/default_image.jpgACTION_PICK
<activity
android:name=".FileSelectActivity"
android:label="@"File Selector" >
<intent-filter>
<action
android:name="android.intent.action.PICK"/>
<category
android:name="android.intent.category.DEFAULT"/>
<category
android:name="android.intent.category.OPENABLE"/>
<data android:mimeType="text/plain"/>
<data android:mimeType="image/*"/>
</intent-filter>
</activity>startActivityForResult()和onActivityResult()中發(fā)起請求、處理結果 File requestFile = new File(mImageFilename[position]);
// Use the FileProvider to get a content URI
try {
fileUri = FileProvider.getUriForFile(
MainActivity.this,
"com.example.myapp.fileprovider",
requestFile);
} catch (IllegalArgumentException e) {
Log.e("File Selector",
"The selected file can't be shared: " +
clickedFilename);
} mResultIntent = new Intent("com.example.myapp.ACTION_RETURN_FILE");
if (fileUri != null) {
// Grant temporary read permission to the content URI
mResultIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
}setFlags()賦予臨時訪問權限更安全，Context.grantUriPermission()賦予的權限只有手動調(diào)用Context.revokeUriPermission()才會被移除 mResultIntent.setDataAndType(
fileUri,
getContentResolver().getType(fileUri));
// Set the result
MainActivity.this.setResult(Activity.RESULT_OK,
mResultIntent);
finish(); mRequestFileIntent = new Intent(Intent.ACTION_PICK);
mRequestFileIntent.setType("image/jpg");
startActivityForResult(mRequestFileIntent, 0); @Override
public void onActivityResult(int requestCode, int resultCode,
Intent returnIntent) {
// If the selection didn't work
if (resultCode != RESULT_OK) {
// Exit without doing anything else
return;
} else {
// Get the file's content URI from the incoming Intent
Uri returnUri = returnIntent.getData();
/*
* Try to open the file for "read" access using the
* returned URI. If the file isn't found, write to the
* error log and return.
*/
try {
/*
* Get the content resolver instance for this context, and use it
* to get a ParcelFileDescriptor for the file.
*/
mInputPFD = getContentResolver().openFileDescriptor(returnUri, "r");
} catch (FileNotFoundException e) {
e.printStackTrace();
Log.e("MainActivity", "File not found.");
return;
}
// Get a regular file descriptor for the file
FileDescriptor fd = mInputPFD.getFileDescriptor();
...
}
}Uri returnUri = returnIntent.getData();
String mimeType = getContentResolver().getType(returnUri);Uri returnUri = returnIntent.getData();
Cursor returnCursor =
getContentResolver().query(returnUri, null, null, null, null);
int nameIndex = returnCursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
int sizeIndex = returnCursor.getColumnIndex(OpenableColumns.SIZE);
nameView.setText(returnCursor.getString(nameIndex));
sizeView.setText(Long.toString(returnCursor.getLong(sizeIndex)));Sharing Files with NFC
發(fā)送文件
<uses-permission android:name="android.permission.NFC" />，<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /><uses-feature android:name="android.hardware.nfc" android:required="true" /> if (PackageManager.hasSystemFeature(PackageManager.FEATURE_NFC) &&
Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
}創(chuàng)建提供文件的回調(diào)
// List of URIs to provide to Android Beam
private Uri[] mFileUris = new Uri[10];
...
/**
* Callback that Android Beam file transfer calls to get
* files to share
*/
private class FileUriCallback implements
NfcAdapter.CreateBeamUrisCallback {
public FileUriCallback() {
}
/**
* Create content URIs as needed to share with another device
*/
@Override
public Uri[] createBeamUris(NfcEvent event) {
return mFileUris;
}
}
...
// Android Beam file transfer is available, continue
...
mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
/*
* Instantiate a new FileUriCallback to handle requests for
* URIs
*/
mFileUriCallback = new FileUriCallback();
// Set the dynamic callback for URI requests.
mNfcAdapter.setBeamPushUrisCallback(mFileUriCallback,this);
... /*
* Create a list of URIs, get a File,
* and set its permissions
*/
private Uri[] mFileUris = new Uri[10];
String transferFile = "transferimage.jpg";
File extDir = getExternalFilesDir(null);
File requestFile = new File(extDir, transferFile);
requestFile.setReadable(true, false);
// Get a URI for the File and add it to the list of URIs
fileUri = Uri.fromFile(requestFile);
if (fileUri != null) {
mFileUris[0] = fileUri;
} else {
Log.e("My Activity", "No File URI available for file.");
} <activity
android:name="com.example.android.nfctransfer.ViewActivity"
android:label="Android Beam Viewer" >
...
<intent-filter>
<action android:name="android.intent.action.VIEW"/>
<category android:name="android.intent.category.DEFAULT"/>
...
</intent-filter>
</activity><uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> // Get the Intent action
mIntent = getIntent();
String action = mIntent.getAction();
/*
* For ACTION_VIEW, the Activity is being asked to display data.
* Get the URI.
*/
if (TextUtils.equals(action, Intent.ACTION_VIEW)) {
// Get the URI from the Intent
Uri beamUri = mIntent.getData();
/*
* Test for the type of URI, by getting its scheme value
*/
if (TextUtils.equals(beamUri.getScheme(), "file")) {
mParentPath = handleFileUri(beamUri);
} else if (TextUtils.equals(
beamUri.getScheme(), "content")) {
mParentPath = handleContentUri(beamUri);
}
} String fileName = beamUri.getPath();
File copiedFile = new File(fileName); ...
public String handleContentUri(Uri beamUri) {
// Position of the filename in the query Cursor
int filenameIndex;
// File object for the filename
File copiedFile;
// The filename stored in MediaStore
String fileName;
// Test the authority of the URI
if (!TextUtils.equals(beamUri.getAuthority(), MediaStore.AUTHORITY)) {
/*
* Handle content URIs for other content providers
*/
// For a MediaStore content URI
} else {
// Get the column that contains the file name
String[] projection = { MediaStore.MediaColumns.DATA };
Cursor pathCursor =
getContentResolver().query(beamUri, projection,
null, null, null);
// Check for a valid cursor
if (pathCursor != null &&
pathCursor.moveToFirst()) {
// Get the column index in the Cursor
filenameIndex = pathCursor.getColumnIndex(
MediaStore.MediaColumns.DATA);
// Get the full file name including path
fileName = pathCursor.getString(filenameIndex);
// Create a File object for the filename
copiedFile = new File(fileName);
// Return the parent directory of the file
return new File(copiedFile.getParent());
} else {
// The query didn't work; return null
return null;
}
}
}
...
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