原文章地址：Android 4.4从图库选择图片,获取图片路径并裁剪
最近在做一个从图库选择图片或拍照,然后裁剪的功能.本来是没问题的,一直在用
[java] view plaincopy在CODE上查看代码片派生到我的代码片
01. Intent intent=new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
的方式来做,是调用系统图库来做,但是发现如果有图片是同步到google相册的话,图库里面能看到一个auto backup的目录,点进去选图片的话是无法获取到图片的路径的.因为那些图片根本就不存在于手机上.然后看到无论是百度贴吧,Instagram,或者还有些会选取图片做修改的app,都是用一个很漂亮的图片选择器(4.4以上,4.3的还是用系统旧的图库).
而这个图片选择器可以屏蔽掉那个auto backup的目录.所以就开始打算用这个图片选择器来选图片了.
这个方法就是
[java] view plaincopy在CODE上查看代码片派生到我的代码片
01. Intent intent=new Intent(Intent.ACTION_GET_CONTENT);//ACTION_OPEN_DOCUMENT
02. intent.addCategory(Intent.CATEGORY_OPENABLE);
03. intent.setType("image/jpeg");
04. if(android.os.Build.VERSION.SDK_INT>=android.os.Build.VERSION_CODES.KITKAT){
05. startActivityForResult(intent, SELECT_PIC_KITKAT);
06. }else{
07. startActivityForResult(intent, SELECT_PIC);
08. }
为什么要分开不同版本呢?其实在4.3或以下可以直接用ACTION_GET_CONTENT的,在4.4或以上,官方建议用ACTION_OPEN_DOCUMENT,但其实都不算太大区别,区别是他们返回的Uri,那个才叫大区别.这就是困扰了我一整天的问题所在了.
4.3或以下,选了图片之后,根据Uri来做处理,很多帖子都有了,我就不详细说了.主要是4.4,如果使用上面pick的原生方法来选图,返回的uri还是正常的,但如果用ACTION_GET_CONTENT的方法,返回的uri跟4.3是完全不一样的,4.3返回的是带文件路径的,而4.4返回的却是content://com.Android.providers.media.documents/document/image:3951这样的,没有路径,只有图片编号的uri.这就导致接下来无法根据图片路径来裁剪的步骤了.
还好找了很多方法,包括加权限啊什么的,中间还试过用一些方法,自己的app没崩溃,倒是让系统图库崩溃了,引发了Java.lang.SecurityException.
[java] view plaincopy在CODE上查看代码片派生到我的代码片
01. Caused by: java.lang.SecurityException: Permission Denial: opening provider com.android.providers.media.MediaDocumentsProvider from ProcessRecord{437b5d88 9494:com.google.android.gallery3d/u0a20} (pid=9494, uid=10020) requires android.permission.MANAGE_DOCUMENTS or android.permission.MANAGE_DOCUMENTS
看来4.4的系统还是有些bug.重点来了,4.4得到的uri,需要以下方法来获取文件的路径
[java] view plaincopy在CODE上查看代码片派生到我的代码片
01. public static String getPath(final Context context, final Uri uri) {
02.
03. final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
04.
05. // DocumentProvider
06. if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
07. // ExternalStorageProvider
08. if (isExternalStorageDocument(uri)) {
09. final String docId = DocumentsContract.getDocumentId(uri);
10. final String[] split = docId.split(":");
11. final String type = split[0];
12.
13. if ("primary".equalsIgnoreCase(type)) {
14. return Environment.getExternalStorageDirectory() + "/" + split[1];
15. }
16.
17. // TODO handle non-primary volumes
18. }
19. // DownloadsProvider
20. else if (isDownloadsDocument(uri)) {
21.
22. final String id = DocumentsContract.getDocumentId(uri);
23. final Uri contentUri = ContentUris.withAppendedId(
24. Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
25.
26. return getDataColumn(context, contentUri, null, null);
27. }
28. // MediaProvider
29. else if (isMediaDocument(uri)) {
30. final String docId = DocumentsContract.getDocumentId(uri);
31. final String[] split = docId.split(":");
32. final String type = split[0];
33.
34. Uri contentUri = null;
35. if ("image".equals(type)) {
36. contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
37. } else if ("video".equals(type)) {
38. contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
39. } else if ("audio".equals(type)) {
40. contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
41. }
42.
43. final String selection = "_id=?";
44. final String[] selectionArgs = new String[] {
45. split[1]
46. };
47.
48. return getDataColumn(context, contentUri, selection, selectionArgs);
49. }
50. }
51. // MediaStore (and general)
52. else if ("content".equalsIgnoreCase(uri.getScheme())) {
53.
54. // Return the remote address
55. if (isGooglePhotosUri(uri))
56. return uri.getLastPathSegment();
57.
58. return getDataColumn(context, uri, null, null);
59. }
60. // File
61. else if ("file".equalsIgnoreCase(uri.getScheme())) {
62. return uri.getPath();
63. }
64.
65. return null;
66. }
67.
68. /**
69. * Get the value of the data column for this Uri. This is useful for
70. * MediaStore Uris, and other file-based ContentProviders.
71. *
72. * @param context The context.
73. * @param uri The Uri to query.
74. * @param selection (Optional) Filter used in the query.
75. * @param selectionArgs (Optional) Selection arguments used in the query.
76. * @return The value of the _data column, which is typically a file path.
77. */
78. public static String getDataColumn(Context context, Uri uri, String selection,
79. String[] selectionArgs) {
80.
81. Cursor cursor = null;
82. final String column = "_data";
83. final String[] projection = {
84. column
85. };
86.
87. try {
88. cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
89. null);
90. if (cursor != null && cursor.moveToFirst()) {
91. final int index = cursor.getColumnIndexOrThrow(column);
92. return cursor.getString(index);
93. }
94. } finally {
95. if (cursor != null)
96. cursor.close();
97. }
98. return null;
99. }
100.
101.
102. /**
103. * @param uri The Uri to check.
104. * @return Whether the Uri authority is ExternalStorageProvider.
105. */
106. public static boolean isExternalStorageDocument(Uri uri) {
107. return "com.android.externalstorage.documents".equals(uri.getAuthority());
108. }
109.
110. /**
111. * @param uri The Uri to check.
112. * @return Whether the Uri authority is DownloadsProvider.
113. */
114. public static boolean isDownloadsDocument(Uri uri) {
115. return "com.android.providers.downloads.documents".equals(uri.getAuthority());
116. }
117.
118. /**
119. * @param uri The Uri to check.
120. * @return Whether the Uri authority is MediaProvider.
121. */
122. public static boolean isMediaDocument(Uri uri) {
123. return "com.android.providers.media.documents".equals(uri.getAuthority());
124. }
125.
126. /**
127. * @param uri The Uri to check.
128. * @return Whether the Uri authority is Google Photos.
129. */
130. public static boolean isGooglePhotosUri(Uri uri) {
131. return "com.google.android.apps.photos.content".equals(uri.getAuthority());
132. }
这样,就可以在4.4上用漂亮的图片选择器,选到我们想要的文件,又不会出问题了.
昨天发现了个bug,如果在4.4上面不用"图片"来选,用"图库"来选,就会无法读取到图片路径,所以只需要加个判断,如果是用旧方式来选,就用旧方式来读,就是如果
DocumentsContract.isDocumentUri(context, uri) 返回false的话,就用旧的方式
[java] view plaincopy在CODE上查看代码片派生到我的代码片
01. public static String selectImage(Context context,Intent data){
02. Uri selectedImage = data.getData();
03. // Log.e(TAG, selectedImage.toString());
04. if(selectedImage!=null){
05. String uriStr=selectedImage.toString();
06. String path=uriStr.substring(10,uriStr.length());
07. if(path.startsWith("com.sec.android.gallery3d")){
08. Log.e(TAG, "It's auto backup pic path:"+selectedImage.toString());
09. return null;
10. }
11. }
12. String[] filePathColumn = { MediaStore.Images.Media.DATA };
13. Cursor cursor = context.getContentResolver().query(selectedImage,filePathColumn, null, null, null);
14. cursor.moveToFirst();
15. int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
16. String picturePath = cursor.getString(columnIndex);
17. cursor.close();
18. return picturePath;
19. }
这样就OK的了
