4.4从图库选择图片,获取图片路径并裁剪

本文主要是介绍4.4从图库选择图片,获取图片路径并裁剪，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

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

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).
图片说明文字

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

Intent intent=new Intent(Intent.ACTION_GET_CONTENT);//ACTION_OPEN_DOCUMENT
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.setType("image/jpeg");
if(android.os.Build.VERSION.SDK_INT>=android.os.Build.VERSION_CODES.KITKAT){                startActivityForResult(intent, SELECT_PIC_KITKAT);  
}else{              startActivityForResult(intent, SELECT_PIC); 
}

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,

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

public static String getPath(final Context context, final Uri uri) {final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;// DocumentProviderif (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {// ExternalStorageProviderif (isExternalStorageDocument(uri)) {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];}// TODO handle non-primary volumes}// DownloadsProviderelse if (isDownloadsDocument(uri)) {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);}// MediaProviderelse if (isMediaDocument(uri)) {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);}}// MediaStore (and general)else if ("content".equalsIgnoreCase(uri.getScheme())) {// Return the remote addressif (isGooglePhotosUri(uri))return uri.getLastPathSegment();return getDataColumn(context, uri, null, null);}// Fileelse if ("file".equalsIgnoreCase(uri.getScheme())) {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 index = cursor.getColumnIndexOrThrow(column);return cursor.getString(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());
}/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is Google Photos.
 */
public static boolean isGooglePhotosUri(Uri uri) {return "com.google.android.apps.photos.content".equals(uri.getAuthority());
}

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

public static String selectImage(Context context,Intent data){Uri selectedImage = data.getData();
//      Log.e(TAG, selectedImage.toString());if(selectedImage!=null){            String uriStr=selectedImage.toString();String path=uriStr.substring(10,uriStr.length());if(path.startsWith("com.sec.android.gallery3d")){Log.e(TAG, "It's auto backup pic path:"+selectedImage.toString());return null;}}       String[] filePathColumn = { MediaStore.Images.Media.DATA };Cursor cursor = context.getContentResolver().query(selectedImage,filePathColumn, null, null, null);cursor.moveToFirst();int columnIndex = cursor.getColumnIndex(filePathColumn[0]);String picturePath = cursor.getString(columnIndex);cursor.close();return picturePath;     }