开启文件管理时 URI获取文件路径为null的解决方法

最近做Android图片相关的开发，通过intent 得到 URI获取的文件路径为null，正好这篇文章解决了我的问题，mark一下

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原文：

今天调用系统自带的FileChooser后，根据Intent返回的uri获取路径的时一直返回null。

这个问题很奇怪，最后发现验证用的华为P7是Android 4.4系统。

先看下4.4之前的uri的形式：

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Uri ： content://media/extenral/images/media/17766

是不是很熟悉？再看4.4及以后的Uri形式：

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content://com.android.providers.media.documents/document/image%2706

日志一打印出来我就明白是什么原因啦。这什么东西在Android 4.4前后不一样，4.4之前content后面是文件全路径，4.4之后不再直接表示路径啦。这就好办啦，翻了翻API后发现4.4以后的Uri还不唯一，并不是统一的一种格式，所以就来个通用解决办法好啦：

4.4以前通过Uri获取路径：data是Uri，filename是一个String的字符串，用来保存路径。

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public static String getPathByUri(Context context, Uri data) {

String filename=null;

if (data.getScheme().toString().compareTo("content") == 0) {

Cursor cursor = context.getContentResolver().query(data, new String[] { "_data" }, null, null, null);

if (cursor.moveToFirst()) {

filename = cursor.getString(0);

}

} else if (data.getScheme().toString().compareTo("file") == 0) {// file:///开头的uri

filename = data.toString();

filename = data.toString().replace("file://", "");// 替换file://

if (!filename.startsWith("/mnt")) {// 加上"/mnt"头

filename += "/mnt";

}

}

return filename;

}

4.4以后根据Uri获取路径：

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// 专为Android4.4设计的从Uri获取文件绝对路径，以前的方法已不好使

@SuppressLint("NewApi")

public static String getPathByUri4kitkat(final Context context, final Uri uri) {

final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

// DocumentProvider

if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {

if (isExternalStorageDocument(uri)) {// ExternalStorageProvider

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];

}

} else if (isDownloadsDocument(uri)) {// DownloadsProvider

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);

} else if (isMediaDocument(uri)) {// MediaProvider

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);

}

} else if ("content".equalsIgnoreCase(uri.getScheme())) {// MediaStore

// (and

// general)

return getDataColumn(context, uri, null, null);

} else if ("file".equalsIgnoreCase(uri.getScheme())) {// File

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());

}

安卓2.3.3 & 4.0.4 & 4.4 &
5.1.1 & 6.0真机亲测都正常，欢迎拷贝！

最后，附上一个Video项目用到的相关函数供参考：

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//return the id of URI

public static int getVideoUriByPath(Uri resultUri, Activity activity, String path){

resultUri= null;

int id=-1;

if(activity==null || path==null)

return id;

Uri preUri = Uri.parse("content://media/external/video/media/");

@SuppressWarnings("deprecation")

Cursor cursor = activity.managedQuery(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, null, null, null, MediaStore.Video.Media.DEFAULT_SORT_ORDER);

cursor.moveToFirst();

while (!cursor.isAfterLast()) {

String data = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Video.Media.DATA));

if (path.equals(data)) {

id = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Video.Media._ID));

resultUri = Uri.withAppendedPath(preUri, "" + id);

break;

}

cursor.moveToNext();

}

return id;

}

我的启动方法

Intent intent = new Intent();

intent.setType("image/*");

intent.setAction(Intent.ACTION_GET_CONTENT);

// CODE = 0

mcontext.startActivityForResult(intent, 0);

// 使用圖庫添加相片

if (requestCode == 0) {

if (resultCode == getActivity().RESULT_OK) {

ContentResolver cr = getActivity().getContentResolver();

Uri uri = data.getData();

Log.e("uri", " === " + uri);

Log.e("uri", "uri getAuthority= " + uri.getAuthority());

Cursor c = cr.query(uri,

new String[] { MediaStore.Images.Media.DATA }, null,

null, null);

String imgPath;

// 说明不是选的相册文件

if (null == c) {

imgPath = uri.getPath();

} else {

c.moveToFirst();

imgPath = c.getString(c

.getColumnIndex(MediaStore.Images.Media.DATA));

Log.e("path", "path = " + imgPath);

if (null == imgPath) {

imgPath = getPathByUri4kitkat(getActivity(), uri);

}

}

Log.e("path", "path = " + imgPath);

dealImg(imgPath);//处理文件的方法

}