在奇巧(或新画廊)之前，意图。ACTION_GET_CONTENT返回一个这样的URI
内容:/ /媒体/外部/图片/媒体/ 3951。
使用ContentResolver并查询 media . data返回文件URL。
然而，在奇巧，画廊返回一个URI(通过“Last”)像这样:
内容:/ / com.android.providers.media.documents /文档/图片:3951
我该怎么处理呢?
当前回答
我相信已经发布的回复应该会让人们朝着正确的方向前进。然而，以下是我所做的对我正在更新的遗留代码有意义的事情。遗留代码使用图库中的URI来更改和保存图像。
在4.4之前(和谷歌驱动器)，uri看起来是这样的: 内容:/ /媒体/外部/图片/媒体/ 41
正如问题中所述，它们通常是这样的: 内容:/ / com.android.providers.media.documents /文档/图片:3951
因为我需要保存图像的能力，而不打扰已经存在的代码，我只是从图库中复制URI到应用程序的数据文件夹中。然后从数据文件夹中保存的图像文件中产生一个新的URI。
这个想法是这样的:
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
startActivityForResult(intent), CHOOSE_IMAGE_REQUEST);
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
File tempFile = new File(this.getFilesDir().getAbsolutePath(), "temp_image");
//Copy URI contents into temporary file.
try {
tempFile.createNewFile();
copyAndClose(this.getContentResolver().openInputStream(data.getData()),new FileOutputStream(tempFile));
}
catch (IOException e) {
//Log Error
}
//Now fetch the new URI
Uri newUri = Uri.fromFile(tempFile);
/* Use new URI object just like you used to */
}
注意- copyAndClose()只是执行文件I/O，将InputStream复制到FileOutputStream。代码没有被发布。
其他回答
试试这个:
if (Build.VERSION.SDK_INT <19){
Intent intent = new Intent();
intent.setType("image/jpeg");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, getResources().getString(R.string.select_picture)),GALLERY_INTENT_CALLED);
} else {
Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.setType("image/jpeg");
startActivityForResult(intent, GALLERY_KITKAT_INTENT_CALLED);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode != Activity.RESULT_OK) return;
if (null == data) return;
Uri originalUri = null;
if (requestCode == GALLERY_INTENT_CALLED) {
originalUri = data.getData();
} else if (requestCode == GALLERY_KITKAT_INTENT_CALLED) {
originalUri = data.getData();
final int takeFlags = data.getFlags()
& (Intent.FLAG_GRANT_READ_URI_PERMISSION
| Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
// Check for the freshest data.
getContentResolver().takePersistableUriPermission(originalUri, takeFlags);
}
loadSomeStreamAsynkTask(originalUri);
}
可能需要
@SuppressLint（“NewApi”）
for
takePersistableUriPermission
问题
如何从URI中获得实际的文件路径
回答
据我所知，我们不需要从URI获取文件路径，因为对于大多数情况，我们可以直接使用URI来完成我们的工作(如1。获取位图2。向服务器发送文件，等等)
1. 发送到服务器
我们可以直接使用URI将文件发送到服务器。
使用URI，我们可以获得InputStream，我们可以使用MultiPartEntity直接将其发送到服务器。
例子
/**
* Used to form Multi Entity for a URI (URI pointing to some file, which we got from other application).
*
* @param uri URI.
* @param context Context.
* @return Multi Part Entity.
*/
public MultipartEntity formMultiPartEntityForUri(final Uri uri, final Context context) {
MultipartEntity multipartEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE, null, Charset.forName("UTF-8"));
try {
InputStream inputStream = mContext.getContentResolver().openInputStream(uri);
if (inputStream != null) {
ContentBody contentBody = new InputStreamBody(inputStream, getFileNameFromUri(uri, context));
multipartEntity.addPart("[YOUR_KEY]", contentBody);
}
}
catch (Exception exp) {
Log.e("TAG", exp.getMessage());
}
return multipartEntity;
}
/**
* Used to get a file name from a URI.
*
* @param uri URI.
* @param context Context.
* @return File name from URI.
*/
public String getFileNameFromUri(final Uri uri, final Context context) {
String fileName = null;
if (uri != null) {
// Get file name.
// File Scheme.
if (ContentResolver.SCHEME_FILE.equals(uri.getScheme())) {
File file = new File(uri.getPath());
fileName = file.getName();
}
// Content Scheme.
else if (ContentResolver.SCHEME_CONTENT.equals(uri.getScheme())) {
Cursor returnCursor =
context.getContentResolver().query(uri, null, null, null, null);
if (returnCursor != null && returnCursor.moveToFirst()) {
int nameIndex = returnCursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
fileName = returnCursor.getString(nameIndex);
returnCursor.close();
}
}
}
return fileName;
}
2. 从URI中获取位图
如果URI指向图像，我们将得到位图，否则为null:
/**
* Used to create bitmap for the given URI.
* <p>
* 1. Convert the given URI to bitmap.
* 2. Calculate ratio (depending on bitmap size) on how much we need to subSample the original bitmap.
* 3. Create bitmap bitmap depending on the ration from URI.
* 4. Reference - http://stackoverflow.com/questions/3879992/how-to-get-bitmap-from-an-uri
*
* @param context Context.
* @param uri URI to the file.
* @param bitmapSize Bitmap size required in PX.
* @return Bitmap bitmap created for the given URI.
* @throws IOException
*/
public static Bitmap createBitmapFromUri(final Context context, Uri uri, final int bitmapSize) throws IOException {
// 1. Convert the given URI to bitmap.
InputStream input = context.getContentResolver().openInputStream(uri);
BitmapFactory.Options onlyBoundsOptions = new BitmapFactory.Options();
onlyBoundsOptions.inJustDecodeBounds = true;
onlyBoundsOptions.inDither = true;//optional
onlyBoundsOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;//optional
BitmapFactory.decodeStream(input, null, onlyBoundsOptions);
input.close();
if ((onlyBoundsOptions.outWidth == -1) || (onlyBoundsOptions.outHeight == -1)) {
return null;
}
// 2. Calculate ratio.
int originalSize = (onlyBoundsOptions.outHeight > onlyBoundsOptions.outWidth) ? onlyBoundsOptions.outHeight : onlyBoundsOptions.outWidth;
double ratio = (originalSize > bitmapSize) ? (originalSize / bitmapSize) : 1.0;
// 3. Create bitmap.
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.inSampleSize = getPowerOfTwoForSampleRatio(ratio);
bitmapOptions.inDither = true;//optional
bitmapOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;//optional
input = context.getContentResolver().openInputStream(uri);
Bitmap bitmap = BitmapFactory.decodeStream(input, null, bitmapOptions);
input.close();
return bitmap;
}
/**
* For Bitmap option inSampleSize - We need to give value in power of two.
*
* @param ratio Ratio to be rounded of to power of two.
* @return Ratio rounded of to nearest power of two.
*/
private static int getPowerOfTwoForSampleRatio(final double ratio) {
int k = Integer.highestOneBit((int) Math.floor(ratio));
if (k == 0) return 1;
else return k;
}
评论
Android没有提供任何从URI获取文件路径的方法，在上面的大多数答案中，我们都硬编码了一些常量，这可能会在功能发布中中断(对不起，我可能错了)。 在直接从URI获取文件路径的解决方案之前，尝试是否可以用URI和Android默认方法解决您的用例。
参考
https://developer.android.com/guide/topics/providers/content-provider-basics.html https://developer.android.com/reference/android/content/ContentResolver.html https://hc.apache.org/httpcomponents-client-ga/httpmime/apidocs/org/apache/http/entity/mime/content/InputStreamBody.html
正如commonware提到的，你不应该假设，你通过ContentResolver得到的流可以转换成文件。
你真正应该做的是从ContentProvider打开InputStream，然后从中创建一个位图。而且它在4.4和更早的版本上也可以工作，不需要反射。
//cxt -> current context
InputStream input;
Bitmap bmp;
try {
input = cxt.getContentResolver().openInputStream(fileUri);
bmp = BitmapFactory.decodeStream(input);
} catch (FileNotFoundException e1) {
}
当然，如果你处理大图片，你应该用适当的inSampleSize: http://developer.android.com/training/displaying-bitmaps/load-bitmap.html加载它们。但那是另一个话题了。
对于这种类型的uri 内容:/ / % 3 a19298 com.android.providers.media.documents /文件/文档 或者uri.getAuthority()是这些中的任何一个
"com.google.android.apps.docs.storage".equals(uri.getAuthority()) || "com.google.android.apps.docs.storage.legacy".equals(uri.getAuthority());
使用这个函数
private static String getDriveFilePath(Uri uri, Context context) {
Uri returnUri = uri;
Cursor returnCursor = context.getContentResolver().query(returnUri, null, null, null, null);
int nameIndex = returnCursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
int sizeIndex = returnCursor.getColumnIndex(OpenableColumns.SIZE);
returnCursor.moveToFirst();
String name = (returnCursor.getString(nameIndex));
String size = (Long.toString(returnCursor.getLong(sizeIndex)));
File file = new File(context.getCacheDir(), name);
try {
InputStream inputStream = context.getContentResolver().openInputStream(uri);
FileOutputStream outputStream = new FileOutputStream(file);
int read = 0;
int maxBufferSize = 1 * 1024 * 1024;
int bytesAvailable = inputStream.available();
//int bufferSize = 1024;
int bufferSize = Math.min(bytesAvailable, maxBufferSize);
final byte[] buffers = new byte[bufferSize];
while ((read = inputStream.read(buffers)) != -1) {
outputStream.write(buffers, 0, read);
}
Log.e("File Size", "Size " + file.length());
inputStream.close();
outputStream.close();
Log.e("File Path", "Path " + file.getPath());
Log.e("File Size", "Size " + file.length());
} catch (Exception e) {
Log.e("Exception", e.getMessage());
}
return file.getPath();
}
请尽量避免使用takePersistableUriPermission方法，因为它会为我引发运行时异常。 ／** 从图库中选择。 * /
public void selectFromGallery() {
if (Build.VERSION.SDK_INT < AppConstants.KITKAT_API_VERSION) {
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
((Activity)mCalledContext).startActivityForResult(intent,AppConstants.GALLERY_INTENT_CALLED);
} else {
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
((Activity)mCalledContext).startActivityForResult(intent, AppConstants.GALLERY_AFTER_KITKAT_INTENT_CALLED);
}
}
OnActivity的结果处理图像数据:
@Override onActivityResult(int requestCode, int resultCode, Intent data) {
//gallery intent result handling before kit-kat version
if(requestCode==AppConstants.GALLERY_INTENT_CALLED
&& resultCode == RESULT_OK) {
Uri selectedImage = data.getData();
String[] filePathColumn = {MediaStore.Images.Media.DATA};
Cursor cursor = getContentResolver().query(selectedImage,filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String filePath = cursor.getString(columnIndex);
cursor.close();
photoFile = new File(filePath);
mImgCropping.startCropImage(photoFile,AppConstants.REQUEST_IMAGE_CROP);
}
//gallery intent result handling after kit-kat version
else if (requestCode == AppConstants.GALLERY_AFTER_KITKAT_INTENT_CALLED
&& resultCode == RESULT_OK) {
Uri selectedImage = data.getData();
InputStream input = null;
OutputStream output = null;
try {
//converting the input stream into file to crop the
//selected image from sd-card.
input = getApplicationContext().getContentResolver().openInputStream(selectedImage);
try {
photoFile = mImgCropping.createImageFile();
} catch (IOException e) {
e.printStackTrace();
}catch(Exception e) {
e.printStackTrace();
}
output = new FileOutputStream(photoFile);
int read = 0;
byte[] bytes = new byte[1024];
while ((read = input.read(bytes)) != -1) {
try {
output.write(bytes, 0, read);
} catch (IOException e) {
e.printStackTrace();
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
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