小米手机Attempt to invoke interface method 'boolean android.database.Cursor.moveToFirst()'

原文：http://blog.csdn.net/iamwutianbao/article/details/52459509

小米手机选择了图片之后，小米机会崩掉（别的机子，啥版本都没问题）。看异常信息，指示cursor.moveToFirst()，空指针异常。也就是说，cursor为空。是uri的问题，4.4之前，返回的是包含图片绝对路劲的，4.4之后，返回的不再是绝对路劲了，而是一个图片的编码。小米不论版本高低，小米机会崩掉，得到的只是一个图片编码。这时需要去转换为绝对路径，才能方便使用。下面方法是可以得到绝对路径的方法，是大神封装好了，封装成了一个pictureHelper工具类。

吐槽一下，除了小米，用ACTION_PICK，都能得到一个图片的绝对路径。如果是小米，用ACTION_PICK，就需要去转化了。但是，小米用ACTION_GET_CONTENT或者ACTION_OPEN_DOCUMENT，低版本，也能得到绝对路径。。最后统一的处理方法就是，用ACTION_GET_CONTENT，然后分版本处理，低版本还是旧的方法，高版本，用pictureHelper工具类处理得到绝对路径。

 package com.xxxe.utils;

 import android.annotation.SuppressLint;
 import android.content.ContentUris;
 import android.content.Context;
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Environment;
 import android.provider.DocumentsContract;
 import android.provider.MediaStore;

 /**
  *  小米手机获取本地相册图片出现空指针异常处理类
  * @author dec
  *
  */

 public class MiPictureHelper {



     @SuppressLint("NewApi")
     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];
                 }
             }
             // 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;

     }

     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;

     }

     public static boolean isExternalStorageDocument(Uri uri) {
         return "com.android.externalstorage.documents".equals(uri.getAuthority());
     }

     public static boolean isDownloadsDocument(Uri uri) {
         return "com.android.providers.downloads.documents".equals(uri.getAuthority());
     }

     public static boolean isMediaDocument(Uri uri) {
         return "com.android.providers.media.documents".equals(uri.getAuthority());
     }

     private static boolean isGooglePhotosUri(Uri uri) {
         return "com.google.android.apps.photos.content".equals(uri.getAuthority());
     }

 }

如果是想要获取相册中图片的路径，直接这样调用：

 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
     switch (requestCode) {
         case PICK_PICTURE:
         // 选取照片
         if(data!=null){
             try {
                 Uri uri = data.getData();
                 String pickPath = MiPictureHelper.getPath(mContext, uri);  // 获取图片路径的方法调用
                 System.out.println("图片路径 -->> " + pickPath);
                 }
             }
         }
     }
 }

====================== 我是一条分割线 ==========================

下面是其他开发者的处理方法

 * 解决小米手机上获取图片路径为null的情况
 * @param intent
 * @return
 */
 public Uri getPictureUri(android.content.Intent intent) {
        Uri uri = intent.getData();
        String type = intent.getType();
        if (uri.getScheme().equals("file") && (type.contains("image/"))) {
            String path = uri.getEncodedPath();
            if (path != null) {
                path = Uri.decode(path);
                ContentResolver cr = this.getContentResolver();
                StringBuffer buff = new StringBuffer();
                buff.append("(").append(Images.ImageColumns.DATA).append("=")
                        .append("'" + path + "'").append(")");
                Cursor cur = cr.query(Images.Media.EXTERNAL_CONTENT_URI,
                        new String[] { Images.ImageColumns._ID },
                        buff.toString(), null, null);
                int index = 0;
                for (cur.moveToFirst(); !cur.isAfterLast(); cur.moveToNext()) {
                    index = cur.getColumnIndex(Images.ImageColumns._ID);
                    // set _id value
                    index = cur.getInt(index);
                }
                if (index == 0) {
                    // do nothing
                } else {
                    Uri uri_temp = Uri
                            .parse("content://media/external/images/media/"
                                    + index);
                    if (uri_temp != null) {
                        uri = uri_temp;
                    }
                }
            }
        }
        return uri;
    }

他们这样调用方法：

 "white-space:pre">    if (data == null) {
         return;
     }
     uri = data.getData();
     uri = getPictureUri(data); // 方法调用
         String[] proj = { MediaStore.Images.Media.DATA };
         Cursor cursor = managedQuery(uri, proj, null, null, null);
         if(cursor!=null) {
         int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
                 cursor.moveToFirst();
                 String path = cursor.getString(column_index);// 图片在的路径
                 Intent intent3 = new Intent(this, SYClipActivity.class);
                 intent3.putExtra("path", path);
                 startActivityForResult(intent3, IMAGE_COMPLETE);
     }