Android 媒体文件读取

我正在尝试读取手机中图像的缩略图。下面的代码在Emulator中运行良好，但在Phone中同样失败。它给出count=0我手机中有很多照片：

String[] img = { MediaStore.Images.Thumbnails._ID };
cursor imagecursor = managedQuery(MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, img,   null,null, MediaStore.Images.Thumbnails.IMAGE_ID + "");
int image_column_index =  imagecursor.getColumnIndexOrThrow(MediaStore.Images.Thumbnails._ID);
count = imagecursor.getCount();
System.err.println("image_column_index= " + image_column_index);
System.err.println("count= " + count);

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嗨，谢谢你的信息。。请找到下面的日志…实际上这里的计数不应该是零

    06-16 15:17:28.360 W/System.err(10250): image_column_index= 0
    06-16 15:17:28.360 W/System.err(10250): count= 0
    06-16 15:17:28.370 W/dalvikvm(10250): threadid=1: thread exiting with uncaught exception (group=0x40020ac0)
    06-16 15:17:28.370 E/AndroidRuntime(10250): FATAL EXCEPTION: main
    06-16 15:17:28.370 E/AndroidRuntime(10250): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.test.imagegallery/com.test.imagegallery.LocalThumbnailActivity}: java.lang.ArrayIndexOutOfBoundsException
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at android.app.ActivityThread.access$2300(ActivityThread.java:125)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at android.os.Handler.dispatchMessage(Handler.java:99)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at android.os.Looper.loop(Looper.java:123)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at android.app.ActivityThread.main(ActivityThread.java:4627)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at java.lang.reflect.Method.invokeNative(Native Method)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at java.lang.reflect.Method.invoke(Method.java:521)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at dalvik.system.NativeStart.main(Native Method)
    06-16 15:17:28.370 E/AndroidRuntime(10250): Caused by: java.lang.ArrayIndexOutOfBoundsException
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at com.test.imagegallery.LocalThumbnailActivity.init_phone_image_grid(LocalThumbnailActivity.java:48)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at com.test.imagegallery.LocalThumbnailActivity.onCreate(LocalThumbnailActivity.java:29)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
    06-16 15:17:28.370 E/AndroidRuntime(10250):     ... 11 more
    06-16 15:17:28.380 W/ActivityManager( 1366):   Force finishing activity com.test.imagegallery/.LocalThumbnailActivity
    06-16 15:17:28.380 W/ActivityManager( 1366):   Force finishing activity com.test.imagegallery/.ImageGallery

这里要实例化的类称为Cursor，它是大写的

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此外，您还应该提供LogCat输出以及收到的任何异常或错误消息。

hi luckas，在这里写问题时，光标是一个打字错误。关于log cat，我在电话中看到了错误，因此我无法在此处复制错误。它显示活动的count=0，然后是ArrayOutOfBoundArray，所以您没有在虚拟设备上进行测试？如果是这样，你应该读一读。嗨，谢谢你提供的信息。。请找到下面的日志…实际上这里的计数不应该是零。count=0 W/dalvikvm 5413:threadid=1:thread退出时未捕获异常组=0x40020ac0 E/AndroidRuntime 5413:致命异常：main E/AndroidRuntime 5413:java.lang.RuntimeException:无法启动活动组件信息{com.ibm.imagegallery/com.ibm.imagegallery.LocalThumbnailActivity}：java.lang.ArrayIndexOutOfBoundsException E/AndroidRuntime 5413:at android.app.ActivityThread.performLaunchActivityActivityThread.jav。。无法显示完整的日志请编辑您的原始帖子并在代码标签中添加LogCat。

cursor imagecursor = managedQuery(...);