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StackOverflow 文件
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Android 教程
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意圖
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顯示檔案選擇器並讀取結果
啟動檔案選擇器活動
public void showFileChooser() {
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
// Update with mime types
intent.setType("*/*");
// Update with additional mime types here using a String[].
intent.putExtra(Intent.EXTRA_MIME_TYPES, mimeTypes);
// Only pick openable and local files. Theoretically we could pull files from google drive
// or other applications that have networked files, but that's unnecessary for this example.
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.putExtra(Intent.EXTRA_LOCAL_ONLY, true);
// REQUEST_CODE = <some-integer>
startActivityForResult(intent, REQUEST_CODE);
}
讀取結果
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// If the user doesn't pick a file just return
if (requestCode != REQUEST_CODE || resultCode != RESULT_OK) {
return;
}
// Import the file
importFile(data.getData());
}
public void importFile(Uri uri) {
String fileName = getFileName(uri);
// The temp file could be whatever you want
File fileCopy = copyToTempFile(uri, File tempFile)
// Done!
}
/**
* Obtains the file name for a URI using content resolvers. Taken from the following link
* https://developer.android.com/training/secure-file-sharing/retrieve-info.html#RetrieveFileInfo
*
* @param uri a uri to query
* @return the file name with no path
* @throws IllegalArgumentException if the query is null, empty, or the column doesn't exist
*/
private String getFileName(Uri uri) throws IllegalArgumentException {
// Obtain a cursor with information regarding this uri
Cursor cursor = getContentResolver().query(uri, null, null, null, null);
if (cursor.getCount() <= 0) {
cursor.close();
throw new IllegalArgumentException("Can't obtain file name, cursor is empty");
}
cursor.moveToFirst();
String fileName = cursor.getString(cursor.getColumnIndexOrThrow(OpenableColumns.DISPLAY_NAME));
cursor.close();
return fileName;
}
/**
* Copies a uri reference to a temporary file
*
* @param uri the uri used as the input stream
* @param tempFile the file used as an output stream
* @return the input tempFile for convenience
* @throws IOException if an error occurs
*/
private File copyToTempFile(Uri uri, File tempFile) throws IOException {
// Obtain an input stream from the uri
InputStream inputStream = getContentResolver().openInputStream(uri);
if (inputStream == null) {
throw new IOException("Unable to obtain input stream from URI");
}
// Copy the stream to the temp file
FileUtils.copyInputStreamToFile(inputStream, tempFile);
return tempFile;
}