Context.managedQuery()和context.getContentResolver()获取Cursor关闭注意事项

时间:2022-06-02 20:38:07

  在获取图片缩略图时,获取游标并进行相关的操作。

Cursor cursor = context.getContentResolver().query(MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI,
THUMBNAIL_STORE_IMAGE,
MediaStore.Images.Thumbnails.IMAGE_ID + " = ?",
new String[]{id + ""},
null);

  出现如下异常:

07-06 09:40:14.945 26649-26671/com.xxx.xxx E/ContentResolver: Cursor leak detected, query params: uri=content://media/external/images/thumbnails, projection=[Ljava.lang.String;@4214bca8, selection=image_id = ?, selectionArgs=[Ljava.lang.String;@421d05f8, sortOrder=null
07-06 09:40:14.945 26649-26671/com.xxx.xxx E/AndroidRuntime: FATAL EXCEPTION: Thread-1075
java.lang.IllegalStateException: Process 26649 exceeded cursor quota 100, will kill it
at android.os.Parcel.readException(Parcel.java:1433)
at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:188)
at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:140)
at android.content.ContentProviderProxy.query(ContentProviderNative.java:366)
at android.content.ContentResolver.query(ContentResolver.java:411)
at android.content.ContentResolver.query(ContentResolver.java:354)
at com.xxx.xxx.utils.localalbum.common.LocalImageHelper.getThumbnail(LocalImageHelper.java:179)
at com.xxx.xxx.utils.localalbum.common.LocalImageHelper.initImage(LocalImageHelper.java:139)
at com.xxx.xxx.utils.localalbum.common.LocalImageHelper$1.run(LocalImageHelper.java:92)
at java.lang.Thread.run(Thread.java:856)

  这是由于游标没有关闭导致的问题。在finnally里面对cursor进行关闭即可。

Cursor cursor = context.getContentResolver().query(MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI,
THUMBNAIL_STORE_IMAGE,
MediaStore.Images.Thumbnails.IMAGE_ID + " = ?",
new String[]{id + ""},
null);
try{
...
}finally {
if(null != cursor){
cursor.close();
}
}

  然而,如果使用Context.managedQuery(),如果在android4.0以上,如果使用了Cursor.close()方法;则会报如下异常:

E/AndroidRuntime(31184): Caused by: android.database.StaleDataException: Attempted to access a cursor after it has been closed.

  在android 4.0及其以上的版本中,Cursor会自动关闭,不需要用户自己关闭。

  解决办法:

if(VERSION.SDK_INT < 14) {
cursor.close();
}