4

我想删除数组列表中的项目选择位置

我的代码是

    List<String> historylist = Arrays.asList(history);
    if (historylist.size()>=3){
        System.out.print("*************************************************");
        Log.i(MyContants.StoredHistory_TAG,"StoredHistory size========="+ String.valueOf(historylist.size()));
        String removePosition=historylist.get(2);
        historylist.remove(removePosition);
    }

但我得到了一个异常 UnsupportedOperationException

错误

    12-20 09:16:27.680: I/StoredHistory Class(5715): StoredHistory size=========3
    12-20 09:16:27.680: D/AndroidRuntime(5715): Shutting down VM
    12-20 09:16:27.684: W/dalvikvm(5715): threadid=1: thread exiting with uncaught exception (group=0x4001d7d0)
    12-20 09:16:27.688: E/AndroidRuntime(5715): FATAL EXCEPTION: main
    12-20 09:16:27.688: E/AndroidRuntime(5715): java.lang.RuntimeException: Unable to start activity ComponentInfo{****PACKAGE NAME*****}: java.lang.UnsupportedOperationException
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at android.app.ActivityThread.access$2300(ActivityThread.java:125)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at android.os.Handler.dispatchMessage(Handler.java:99)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at android.os.Looper.loop(Looper.java:123)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at android.app.ActivityThread.main(ActivityThread.java:4627)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at java.lang.reflect.Method.invokeNative(Native Method)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at java.lang.reflect.Method.invoke(Method.java:521)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at dalvik.system.NativeStart.main(Native Method)
    12-20 09:16:27.688: E/AndroidRuntime(5715): Caused by: java.lang.UnsupportedOperationException
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at java.util.AbstractList.remove(AbstractList.java:645)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at java.util.AbstractList$SimpleListIterator.remove(AbstractList.java:77)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at java.util.AbstractCollection.remove(AbstractCollection.java:230)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at ******.utills.StoredHistory.storedHistorylist(StoredHistory.java:24)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at *******.ScanResult.onCreate(ScanResult.java:53)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
    12-20 09:16:27.688: E/AndroidRuntime(5715):     ... 11 more

如何解决这个问题..提前谢谢老兄

4

4 回答 4

6

改变

List<String> historylist = Arrays.asList(history);

至

 List<String> historylist = new LinkedList (Arrays.asList(history));

并查看这篇文章为什么在 List 的情况下会发生此错误：

尝试从列表中删除元素时，为什么会收到 UnsupportedOperationException？

于 2012-12-20T04:04:49.153 回答
5

您不能从返回的列表中添加或删除元素，Arrays.asList因为该列表由原始数组支持。要创建可以修改的列表，您可以执行以下操作：

List<String> historylist = new ArrayList<String>(Arrays.asList(history));
于 2012-12-20T04:05:07.247 回答
1

我相信 Arrays.asList() 创建是固定长度的，因此不支持删除。

尝试使用支持像 ArrayList 之类的删除的实现。

于 2012-12-20T04:05:15.630 回答
0

尝试这个

 list.set(position,obj);
于 2015-05-27T17:52:43.523 回答