环境(Linux/Eclipse Dev for Xoom Tablet 运行 HoneyComb 3.0.1)
在我的应用程序中,我使用相机 (startIntentForResult()) 拍照。拍照后,我得到 onActivityResult() 回调,并且能够使用通过“拍照” Intent 传递的 Uri 加载位图。那时我的 Activity 恢复了,尝试将图像重新加载到图库时出现错误:
FATAL EXCEPTION: main
ERROR/AndroidRuntime(4148): java.lang.RuntimeException: Unable to resume activity {...}:
java.lang.IllegalStateException: trying to requery an already closed cursor
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2243)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1019)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:126)
at android.app.ActivityThread.main(ActivityThread.java:3997)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:491)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalStateException: trying to requery an already closed cursor
at android.app.Activity.performRestart(Activity.java:4337)
at android.app.Activity.performResume(Activity.java:4360)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2205)
... 10 more
我使用的唯一光标逻辑是,在拍摄图像后,我使用以下逻辑将 Uri 转换为文件
String [] projection = {
MediaStore.Images.Media._ID,
MediaStore.Images.ImageColumns.ORIENTATION,
MediaStore.Images.Media.DATA
};
Cursor cursor = activity.managedQuery(
uri,
projection, // Which columns to return
null, // WHERE clause; which rows to return (all rows)
null, // WHERE clause selection arguments (none)
null); // Order-by clause (ascending by name)
int fileColumnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
if (cursor.moveToFirst()) {
return new File(cursor.getString(fileColumnIndex));
}
return null;
任何想法我做错了什么?
最佳答案
在 Honeycomb API 中似乎不推荐使用 managedQuery() 调用。
managedQuery() 的文档内容如下:
This method is deprecated.
Use CursorLoader instead.
Wrapper around query(android.net.Uri, String[], String, String[], String)
that the resulting Cursor to call startManagingCursor(Cursor) so that the
activity will manage its lifecycle for you. **If you are targeting HONEYCOMB
or later, consider instead using LoaderManager instead, available via
getLoaderManager()**.
我还注意到我在查询后调用 cursor.close(),我猜这是一个禁忌。找到这个 really helpful link也是。经过一番阅读,我想出了这个似乎可行的改变。
// causes problem with the cursor in Honeycomb
Cursor cursor = activity.managedQuery(
uri,
projection, // Which columns to return
null, // WHERE clause; which rows to return (all rows)
null, // WHERE clause selection arguments (none)
null); // Order-by clause (ascending by name)
// -------------------------------------------------------------------
// works in Honeycomb
String selection = null;
String[] selectionArgs = null;
String sortOrder = null;
CursorLoader cursorLoader = new CursorLoader(
activity,
uri,
projection,
selection,
selectionArgs,
sortOrder);
Cursor cursor = cursorLoader.loadInBackground();
关于Android 错误 : java. lang.IllegalStateException:试图重新查询已经关闭的游标,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/5915597/