我尝试了一个解决方案（见下文）工作正常，但在Android 4.4中调用startActivityForResult()会调出一个名为“Open from”的活动，其中包含“Recent”，“Images”，“Downloads”以及几个可供挑选的应用程序。当我选择“图像”并尝试解析返回的内容URI（使用下面的代码）时，对cursor.getString()的调用将返回null。如果我使用Gallery应用程序选择完全相同的文件，cursor.getString()将返回文件路径。我只在API级别16和19中对此进行了测试。一切都按照预期的方式运行。至于19，我必须选择图库或其他应用程序，否则它不起作用。
private String getRealPathFromURI(Context context, Uri contentUri) {
Cursor cursor = null;
try {
String[] proj = { MediaStore.Images.Media.DATA };
cursor = context.getContentResolver().query(contentUri, proj, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
String path = cursor.getString(column_index);
return path;
} finally {
if (cursor != null) {
cursor.close();
}
}
}
答案 0 :(得分：89)
这将从MediaProvider，DownloadsProvider和ExternalStorageProvider获取文件路径，同时回退到您提到的非官方ContentProvider方法。
/**
* Get a file path from a Uri. This will get the the path for Storage Access
* Framework Documents, as well as the _data field for the MediaStore and
* other file-based ContentProviders.
*
* @param context The context.
* @param uri The Uri to query.
* @author paulburke
*/
public static String getPath(final Context context, final Uri uri) {
final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
// DocumentProvider
if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
// ExternalStorageProvider
if (isExternalStorageDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
if ("primary".equalsIgnoreCase(type)) {
return Environment.getExternalStorageDirectory() + "/" + split[1];
}
// TODO handle non-primary volumes
}
// DownloadsProvider
else if (isDownloadsDocument(uri)) {
final String id = DocumentsContract.getDocumentId(uri);
final Uri contentUri = ContentUris.withAppendedId(
Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
}
// MediaProvider
else if (isMediaDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = "_id=?";
final String[] selectionArgs = new String[] {
split[1]
};
return getDataColumn(context, contentUri, selection, selectionArgs);
}
}
// MediaStore (and general)
else if ("content".equalsIgnoreCase(uri.getScheme())) {
return getDataColumn(context, uri, null, null);
}
// File
else if ("file".equalsIgnoreCase(uri.getScheme())) {
return uri.getPath();
}
return null;
}
/**
* Get the value of the data column for this Uri. This is useful for
* MediaStore Uris, and other file-based ContentProviders.
*
* @param context The context.
* @param uri The Uri to query.
* @param selection (Optional) Filter used in the query.
* @param selectionArgs (Optional) Selection arguments used in the query.
* @return The value of the _data column, which is typically a file path.
*/
public static String getDataColumn(Context context, Uri uri, String selection,
String[] selectionArgs) {
Cursor cursor = null;
final String column = "_data";
final String[] projection = {
column
};
try {
cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
null);
if (cursor != null && cursor.moveToFirst()) {
final int column_index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(column_index);
}
} finally {
if (cursor != null)
cursor.close();
}
return null;
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is ExternalStorageProvider.
*/
public static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is DownloadsProvider.
*/
public static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is MediaProvider.
*/
public static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri.getAuthority());
}
答案 1 :(得分：43)
将内容：// URI转换为Android 4.4中的实际路径
在任何Android版本上都没有可靠的方法。 content:// Uri不必代表文件系统上的文件，更不用说您可以访问的文件了。
Android 4.4提供存储框架的更改只会增加您遇到content:// Uri值的频率。
如果您获得content:// Uri，请使用ContentResolver以及openInputStream()和openOutputStream()等方法使用它。
答案 2 :(得分：9)
我也一直面临这个问题，但在我的情况下，我想要做的是指定一个具体的Uri到画廊，以便我以后可以使用裁剪。看起来在KitKat的新文档浏览器中我们不能再这样做了，除非你在导航抽屉中选择galery，并且，就像你说的那样，直接从那里打开图像或文件。
在Uri的情况下，您仍然可以从文档浏览器打开时检索路径。
Intent dataIntent= new Intent(Intent.ACTION_GET_CONTENT);
dataIntent.setType("image/*"); //Or whatever type you need
然后在onActivityResult：
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == ACTIVITY_SELECT_IMAGE && resultCode == RESULT_OK) {
myUri = data.getData();
String path = myUri.getPath();
openPath(myUri);
}
}
如果您需要打开包含该路径的文件，您只需使用内容解析器：
public void openPath(Uri uri){
InputStream is = null;
try {
is = getContentResolver().openInputStream(uri);
//Convert your stream to data here
is.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
答案 3 :(得分：7)
在a Google API中介绍。你可以试试这个：
private Bitmap getBitmapFromUri(Uri uri) throws IOException {
ParcelFileDescriptor parcelFileDescriptor =
getContentResolver().openFileDescriptor(uri, "r");
FileDescriptor fileDescriptor = parcelFileDescriptor.getFileDescriptor();
Bitmap image = BitmapFactory.decodeFileDescriptor(fileDescriptor);
parcelFileDescriptor.close();
return image;
}
答案 4 :(得分：1)
如果您确实需要文件路径。首先，使用ContentResolver获取数据。然后，您可以将数据保存到临时文件并使用该路径。
（我必须在函数参数中使用带有File对象的库。）
答案 5 :(得分：0)
感谢@FireBear，我现在修改了答案，我们将获得媒体文件的路径
String filePath = saveBitmap（activity，getBitmapFromUri（imageUri），＆＃34; tmpFile＆＃34;）。getPath（）;
private Bitmap getBitmapFromUri(Context context, Uri uri) throws IOException {
ParcelFileDescriptor parcelFileDescriptor =
context.getContentResolver().openFileDescriptor(uri, "r");
FileDescriptor fileDescriptor = parcelFileDescriptor.getFileDescriptor();
Bitmap image = BitmapFactory.decodeFileDescriptor(fileDescriptor);
parcelFileDescriptor.close();
return image;
}
private File saveBitmap(Context context, Bitmap bitmap, String name) {
File filesDir = context.getFilesDir();
File imageFile = new File(filesDir, name + ".jpg");
OutputStream os;
try {
os = new FileOutputStream(imageFile);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, os);
os.flush();
os.close();
} catch (Exception e) {
//Log.e(getClass().getSimpleName(), "Error writing bitmap", e);
}
return imageFile;
}
答案 6 :(得分：0)
我知道它本身并不能回答问题，但正如@CommonsWare 难过的那样，SAF 并不打算使用这种方式。
可能的一种选择是在应用程序的外部文件目录中创建文件的副本，使用它然后将其删除。
public File createFileCopy(Context context, DocumentFile file) {
if (file == null || !file.exists() || file.getName() == null) {
throw new IllegalArgumentException("The file must no be null, and must exist, and must have a name.");
}
File fileCopy = new File(context.getExternalFilesDir(null).getAbsolutePath(), file.getName());
try {
android.os.FileUtils.copy(openFileInputStream(file), new FileOutputStream(fileCopy));
return fileCopy;
} catch (Exception e) {
// do whateveer you want with this exceeption
e.printStackTrace();
}
return null;
}
答案 7 :(得分：-2)
从Uri获取文件路径： - 我创建了一个Util类，它将获取 存储访问框架文档 的路径，以及 MediaStore 的_data字段以及其他 基于文件的ContentProviders 。
ConvertUriToFilePath： -
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
import android.support.annotation.RequiresApi;
public class ConvertUriToFilePath {
/**
* Get a file path from a Uri. This will get the the path for Storage Access
* Framework Documents, as well as the _data field for the MediaStore and
* other file-based ContentProviders.
*
* @param context The context.
* @param uri The Uri to query.
*/
@RequiresApi(api = Build.VERSION_CODES.KITKAT)
public static String getPathFromURI(final Context context, final Uri uri) {
final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
// DocumentProvider
if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
// ExternalStorageProvider
if (isExternalStorageDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
if ("primary".equalsIgnoreCase(type)) {
return Environment.getExternalStorageDirectory() + "/" + split[1];
}
// TODO handle non-primary volumes
}
// DownloadsProvider
else if (isDownloadsDocument(uri)) {
final String id = DocumentsContract.getDocumentId(uri);
final Uri contentUri = ContentUris.withAppendedId(
Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
}
// MediaProvider
else if (isMediaDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = "_id=?";
final String[] selectionArgs = new String[]{
split[1]
};
return getDataColumn(context, contentUri, selection, selectionArgs);
}
}
// MediaStore (and general)
else if ("content".equalsIgnoreCase(uri.getScheme())) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = "_id=?";
final String[] selectionArgs = new String[]{
split[1]
};
return getDataColumn(context, contentUri, selection, selectionArgs);
// return getDataColumn(context, uri, null, null);
}
// File
else if ("file".equalsIgnoreCase(uri.getScheme())) {
return uri.getPath();
}
return null;
}
/**
* Get the value of the data column for this Uri. This is useful for
* MediaStore Uris, and other file-based ContentProviders.
*
* @param context The context.
* @param uri The Uri to query.
* @param selection (Optional) Filter used in the query.
* @param selectionArgs (Optional) Selection arguments used in the query.
* @return The value of the _data column, which is typically a file path.
*/
public static String getDataColumn(Context context, Uri uri, String selection,
String[] selectionArgs) {
Cursor cursor = null;
final String column = "_data";
final String[] projection = {
column
};
try {
cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
null);
if (cursor != null && cursor.moveToFirst()) {
final int column_index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(column_index);
}
} finally {
if (cursor != null)
cursor.close();
}
return null;
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is ExternalStorageProvider.
*/
public static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is DownloadsProvider.
*/
public static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is MediaProvider.
*/
public static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri.getAuthority());
}
}
示例代码：
// Just call this function of ConvertUriToFilePath class and it will return full path of file URI.
String actualFilepath= ConvertUriToFilePath.getPathFromURI(activity,tempUri);