获取图像缩略图文件路径

Question

我正在尝试获取thumnail路径，而不是位图对象
当我查询这些时，由于某种原因，一些缩略图路径为空。（我的设备中有1028个缩略图，光标长度确实是1028，但仍然返回null）我知道有1028张缩略图，因为我检查了。这是我的代码：

     String[] projection = {MediaStore.Images.Thumbnails._ID};
  // Create the cursor pointing to the SDCard
  cursor = this.getContentResolver().query( MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI,
          projection, // Which columns to return
          null,       // Return all rows
          null,
          MediaStore.Images.Thumbnails.IMAGE_ID);
  // Get the column index of the Thumbnails Image ID
  Log.d(Global.TAG, "BEFORE");
  columnIndex = cursor.getColumnIndex(MediaStore.Images.Thumbnails._ID);
  Log.d(Global.TAG, "AFTER1");
  for(int i =0;i<cursor.getCount();i++){
      cursor.moveToPosition(i);
      Log.d("MyTag","BBABA" + i +" : " + getThumbnailPathForLocalFile(cursor.getLong(columnIndex)));
  }
  cursor.close();

我的getThumbnailPathForLocalFile:

    String getThumbnailPathForLocalFile(long fileId)
 {
    // Log.d(Global., msg)
     Cursor thumbCursor = null;
     try
     {
         thumbCursor = this.getContentResolver().
                 query(MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI
                 , null
                 , MediaStore.Images.Thumbnails.IMAGE_ID + " = " + fileId+ " AND "
                   + MediaStore.Images.Thumbnails.KIND + " = "
                   + MediaStore.Images.Thumbnails.MINI_KIND , null, null);
         if(thumbCursor.moveToFirst())
         {
             // the path is stored in the DATA column
             int dataIndex = thumbCursor.getColumnIndexOrThrow( MediaStore.MediaColumns.DATA );
             String thumbnailPath = thumbCursor.getString(dataIndex);
             return thumbnailPath;
         }
     }
     finally
     {
         if(thumbCursor != null)
         {
             thumbCursor.close();
         }
     }
     return null;
 }

这是我的日志：http://pastebin.com/UZLZF9Pg

经过检查，我发现我发送的id就像for循环的索引一样。我甚至不确定我的代码是否应该工作，所以任何其他代码都会很棒。

Answer 1

您应该查询MediaStore.Images.Thumbnails.DATA。要修改您的示例，它看起来是这样的。

String[] projection = {MediaStore.Images.Thumbnails.DATA};
// Create the cursor pointing to the SDCard
    Cursor cursor = this.getContentResolver().query( MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI,
        projection, // Which columns to return
        null,       // Return all rows
        null,
        null);
// Get the column index of the Thumbnails Image ID
Log.d(TAG, "BEFORE");
int columnIndex = cursor.getColumnIndex(MediaStore.Images.Thumbnails.DATA);
Log.d(TAG, "AFTER1");
for(int i =0;i<cursor.getCount();i++){
    cursor.moveToPosition(i);
    Log.d("MyTag","BBABA" + i +" : " + cursor.getString(columnIndex));
}
cursor.close();

参考：如何从图像的缩略图路径中获取图像路径？