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以下是我获取给定图像缩略图的代码。 截至目前,我得到的例外是'光标越界'使用ContentResolver和Cursor获取Android中图像的缩略图
我认为这可能是因为我没有在任何地方追加图像URL。我对于在哪里做到这一点有点困惑。 所以2个问题:1。 我在哪里可以使用图像的URL,其中我想获得一个缩略图 2. for循环这是应该打印的列名打印只按第一条语句“列名”
//get the corresponding thumbnail
String lastImageTakenPath = MyActivity.this.savedInstanceStateVariable.getString("lastImageTaken");
System.out.println("previous image is "+ lastImageTakenPath);
ContentResolver cr = getContentResolver();
if(cr != null){
String[] projection = { MediaStore.Images.Media._ID };
Cursor cursor = managedQuery(MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI,projection,null,null,null);
//Cursor cursor = cr.query(lastImageTakenURI, null, null, null, null);
//Activity.startManagingCursor(cursor);
if(cursor != null){
String[] columnNames = cursor.getColumnNames();
System.out.println("COLUMN NAMES");
for(int i=0;i<columnNames.length; i++){
System.out.println(columnNames[i]);
}
/* 1. get the id of the image
* 2. use this id in the call, getThumbnails on MediaStore.Images.Thumbnails to obtain the
thumbnail
3.set the imageview's src to this thumbnail */
int imageID = cursor.getInt(cursor.getColumnIndex(MediaStore.Images.Media._ID));
Uri uri = Uri.withAppendedPath(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, Integer.toString(imageID));
// Get original image ID
String url = uri.toString();
int originalImageId = Integer.parseInt(url.substring(url.lastIndexOf("/") + 1, url.length()));
// Get (or create upon demand) the micro thumbnail for the original image.
thumbnailLastImage = MediaStore.Images.Thumbnails.getThumbnail(cr, originalImageId, MediaStore.Images.Thumbnails.MICRO_KIND,null);
thumbnailImage.setImageBitmap(thumbnailLastImage);
}
else{
System.out.println("Cursor is NULL");
}
}
else{
Log.d(TAG,"ContentResolver is NULL");
}
我觉得managedQuery()中的URI应该像这样MediaStore.Images.Media.EXTERNAL_CONTENT_URI而不是MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI。 – Vamsi 2012-01-04 06:29:34