1.Android4.4以上版本的呼叫程式碼：

    public static String getPath(final Context context, final Uri uri) {  
      
        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;  
      
        // DocumentProvider  
        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {  
            // ExternalStorageProvider  
            if (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  
            }  
            // DownloadsProvider  
            else 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);  
            }  
            // MediaProvider  
            else 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 address  
            if (isGooglePhotosUri(uri))  
                return uri.getLastPathSegment();  
      
            return getDataColumn(context, uri, null, null);  
        }  
        // File  
        else 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());  
    }  
 

2.Android 4.4以下版本需要呼叫的方法：

    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;       
        }  
 

3.將路徑轉為正常的Uri

• 如果我們需要在獲取了圖片的系統路徑後呼叫系統的裁剪去裁剪圖片的話，需要將路徑轉為Uri,這裡貼出程式碼

• 	/**
  	 * 路徑轉uri,需要真實的路徑
  	 */
  	public static Uri pathToUri(String path){
  		Uri uri = Uri.fromFile(new File(path));
  		if (uri!=null) {
  			return uri;
  		}
  		return null;
  	}

4.怎樣判斷手機系統的版本，什麼時候使用新的載入獲取路徑方法

/**
		 * 判斷是不是舊的方式
		 * 4.4以後新特徵  
		 */
		//這裡是android版本的判斷
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {  
        	//這裡如果是false，就是舊版本的uri
        	if (DocumentsContract.isDocumentUri(this, uri)) {
    			String path = ImageService.getPath(this, uri);
    			uri = FileUtils.pathToUri(path);
    		}
        } else {
        	/**
        	 * 這裡selectImage需要傳的data是onActivityResult的返回,
        	 * 當然你也可以在這裡不做處理，這裡會採用系統預設的uri ,並不會
        	 * 轉義,我實際專案中沒有做這裡的else判斷，使用預設的uri,即返回的
        	 * data.getData()
        	 */
			String path = ImageService.selectImage(this, data);
			uri = FileUtils.pathToUri(path);
		}