这将为您提供所选文件夹的实际路径它仅适用于属于本地存储的文件/文件夹。
Uri treeUri = data.getData();
String path = FileUtil.getFullPathFromTreeUri(treeUri,this);
其中 FileUtil 是以下类
public final class FileUtil {
private static final String PRIMARY_VOLUME_NAME = "primary";
@Nullable
public static String getFullPathFromTreeUri(@Nullable final Uri treeUri, Context con) {
if (treeUri == null) return null;
String volumePath = getVolumePath(getVolumeIdFromTreeUri(treeUri),con);
if (volumePath == null) return File.separator;
if (volumePath.endsWith(File.separator))
volumePath = volumePath.substring(0, volumePath.length() - 1);
String documentPath = getDocumentPathFromTreeUri(treeUri);
if (documentPath.endsWith(File.separator))
documentPath = documentPath.substring(0, documentPath.length() - 1);
if (documentPath.length() > 0) {
if (documentPath.startsWith(File.separator))
return volumePath + documentPath;
else
return volumePath + File.separator + documentPath;
}
else return volumePath;
}
private static String getVolumePath(final String volumeId, Context context) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP)
return null;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R)
return getVolumePathForAndroid11AndAbove(volumeId, context);
else
return getVolumePathBeforeAndroid11(volumeId, context);
}
private static String getVolumePathBeforeAndroid11(final String volumeId, Context context){
try {
StorageManager mStorageManager = (StorageManager) context.getSystemService(Context.STORAGE_SERVICE);
Class<?> storageVolumeClazz = Class.forName("android.os.storage.StorageVolume");
Method getVolumeList = mStorageManager.getClass().getMethod("getVolumeList");
Method getUuid = storageVolumeClazz.getMethod("getUuid");
Method getPath = storageVolumeClazz.getMethod("getPath");
Method isPrimary = storageVolumeClazz.getMethod("isPrimary");
Object result = getVolumeList.invoke(mStorageManager);
final int length = Array.getLength(result);
for (int i = 0; i < length; i++) {
Object storageVolumeElement = Array.get(result, i);
String uuid = (String) getUuid.invoke(storageVolumeElement);
Boolean primary = (Boolean) isPrimary.invoke(storageVolumeElement);
if (primary && PRIMARY_VOLUME_NAME.equals(volumeId)) // primary volume?
return (String) getPath.invoke(storageVolumeElement);
if (uuid != null && uuid.equals(volumeId)) // other volumes?
return (String) getPath.invoke(storageVolumeElement);
}
// not found.
return null;
} catch (Exception ex) {
return null;
}
}
@TargetApi(Build.VERSION_CODES.R)
private static String getVolumePathForAndroid11AndAbove(final String volumeId, Context context) {
try {
StorageManager mStorageManager = (StorageManager) context.getSystemService(Context.STORAGE_SERVICE);
List<StorageVolume> storageVolumes = mStorageManager.getStorageVolumes();
for (StorageVolume storageVolume : storageVolumes) {
// primary volume?
if (storageVolume.isPrimary() && PRIMARY_VOLUME_NAME.equals(volumeId))
return storageVolume.getDirectory().getPath();
// other volumes?
String uuid = storageVolume.getUuid();
if (uuid != null && uuid.equals(volumeId))
return storageVolume.getDirectory().getPath();
}
// not found.
return null;
} catch (Exception ex) {
return null;
}
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private static String getVolumeIdFromTreeUri(final Uri treeUri) {
final String docId = DocumentsContract.getTreeDocumentId(treeUri);
final String[] split = docId.split(":");
if (split.length > 0) return split[0];
else return null;
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private static String getDocumentPathFromTreeUri(final Uri treeUri) {
final String docId = DocumentsContract.getTreeDocumentId(treeUri);
final String[] split = docId.split(":");
if ((split.length >= 2) && (split[1] != null)) return split[1];
else return File.separator;
}
}
更新：
要解决评论中提到的下载问题：如果您Downloads从默认 Android 文件选择器的左侧抽屉中选择，您实际上并没有选择目录。下载是一个提供者。一个普通的文件夹树 uri 看起来像这样：
content://com.android.externalstorage.documents/tree/primary%3ADCIM
下载的树 uri 是
content://com.android.providers.downloads.documents/tree/downloads
你可以看到一个说externalstorage，而另一个说providers。这就是为什么它不能与文件系统中的目录匹配的原因。因为它不是目录。
解决方案：您可以添加相等性检查，如果树 uri 等于该值，则返回默认下载文件夹路径，可以这样检索：
Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
如果您愿意，可以为所有提供商做类似的事情。我认为它会正常工作most of the time。但我想在某些极端情况下它不会。
感谢@DuhVir 支持 Android R 案例