什么是最简单的方法从android.net.Uri对象持有一个文件:类型转换为java.io.File对象在Android?
我尝试了下面的方法，但不管用:
File file = new File(Environment.getExternalStorageDirectory(), "read.me");
Uri uri = Uri.fromFile(file);
File auxFile = new File(uri.toString());
assertEquals(file.getAbsolutePath(), auxFile.getAbsolutePath());
当前回答
你可以使用这个函数从uri中获取文件在新的android和旧的
fun getFileFromUri(context: Context, uri: Uri?): File? {
uri ?: return null
uri.path ?: return null
var newUriString = uri.toString()
newUriString = newUriString.replace(
"content://com.android.providers.downloads.documents/",
"content://com.android.providers.media.documents/"
)
newUriString = newUriString.replace(
"/msf%3A", "/image%3A"
)
val newUri = Uri.parse(newUriString)
var realPath = String()
val databaseUri: Uri
val selection: String?
val selectionArgs: Array<String>?
if (newUri.path?.contains("/document/image:") == true) {
databaseUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
selection = "_id=?"
selectionArgs = arrayOf(DocumentsContract.getDocumentId(newUri).split(":")[1])
} else {
databaseUri = newUri
selection = null
selectionArgs = null
}
try {
val column = "_data"
val projection = arrayOf(column)
val cursor = context.contentResolver.query(
databaseUri,
projection,
selection,
selectionArgs,
null
)
cursor?.let {
if (it.moveToFirst()) {
val columnIndex = cursor.getColumnIndexOrThrow(column)
realPath = cursor.getString(columnIndex)
}
cursor.close()
}
} catch (e: Exception) {
Log.i("GetFileUri Exception:", e.message ?: "")
}
val path = realPath.ifEmpty {
when {
newUri.path?.contains("/document/raw:") == true -> newUri.path?.replace(
"/document/raw:",
""
)
newUri.path?.contains("/document/primary:") == true -> newUri.path?.replace(
"/document/primary:",
"/storage/emulated/0/"
)
else -> return null
}
}
return if (path.isNullOrEmpty()) null else File(path)
}
其他回答
在寻找了很长一段时间后，这对我来说是有效的:
File file = new File(getPath(uri));
public String getPath(Uri uri)
{
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
if (cursor == null) return null;
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
String s=cursor.getString(column_index);
cursor.close();
return s;
}
经过大量的搜索和尝试不同的方法，我发现这个方法适用于不同的Android版本: 首先复制这个函数:
fun getRealPathFromUri(context: Context, contentUri: Uri): String {
var cursor: Cursor? = null
try {
val proj: Array<String> = arrayOf(MediaStore.Images.Media.DATA)
cursor = context.contentResolver.query(contentUri, proj, null, null, null)
val columnIndex = cursor?.getColumnIndexOrThrow(MediaStore.Images.Media.DATA)
cursor?.moveToFirst()
return columnIndex?.let { cursor?.getString(it) } ?: ""
} finally {
cursor?.close()
}
}
然后，生成一个像这样的文件:
File(getRealPathFromUri(context, uri))
你想要的是…
new File(uri.getPath());
．.． ,而不是……
new File(uri.toString());
笔记
对于android.net.Uri对象，它被命名为uri并完全按照问题中创建，uri. tostring()返回一个“file:///mnt/sdcard/myPicture.jpg”格式的字符串，而uri. getpath()返回一个“/mnt/sdcard/myPicture.jpg”格式的字符串。 我知道在Android系统中文件存储有一些细微差别。在这个回答中，我的意图是准确地回答提问者所问的问题，而不是深究其中的细微差别。
你可以使用这个函数从uri中获取文件在新的android和旧的
fun getFileFromUri(context: Context, uri: Uri?): File? {
uri ?: return null
uri.path ?: return null
var newUriString = uri.toString()
newUriString = newUriString.replace(
"content://com.android.providers.downloads.documents/",
"content://com.android.providers.media.documents/"
)
newUriString = newUriString.replace(
"/msf%3A", "/image%3A"
)
val newUri = Uri.parse(newUriString)
var realPath = String()
val databaseUri: Uri
val selection: String?
val selectionArgs: Array<String>?
if (newUri.path?.contains("/document/image:") == true) {
databaseUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
selection = "_id=?"
selectionArgs = arrayOf(DocumentsContract.getDocumentId(newUri).split(":")[1])
} else {
databaseUri = newUri
selection = null
selectionArgs = null
}
try {
val column = "_data"
val projection = arrayOf(column)
val cursor = context.contentResolver.query(
databaseUri,
projection,
selection,
selectionArgs,
null
)
cursor?.let {
if (it.moveToFirst()) {
val columnIndex = cursor.getColumnIndexOrThrow(column)
realPath = cursor.getString(columnIndex)
}
cursor.close()
}
} catch (e: Exception) {
Log.i("GetFileUri Exception:", e.message ?: "")
}
val path = realPath.ifEmpty {
when {
newUri.path?.contains("/document/raw:") == true -> newUri.path?.replace(
"/document/raw:",
""
)
newUri.path?.contains("/document/primary:") == true -> newUri.path?.replace(
"/document/primary:",
"/storage/emulated/0/"
)
else -> return null
}
}
return if (path.isNullOrEmpty()) null else File(path)
}
public String getRealPathFromURI（Uri uri） {
String result;
Cursor cursor = getContentResolver().query(uri, null, null, null, null);
if (cursor == null) {
result = uri.getPath();
cursor.close();
return result;
}
cursor.moveToFirst();
int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
result = cursor.getString(idx);
cursor.close();
return result;
}
然后使用从URI中获取文件:
File finalFile = newFile(getRealPathFromURI(uri));
——希望能帮到你----
