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如何使用 onSaveInstanceState() 和 onRestoreInstanceState() 保存和恢复多维数组？

我正在使用 ExpandableListView。我有以下团体和孩子。

public static String[] groups = new String[] { "New York", "California",
        "Washington", "Florida", "Iowa"};
public static String[][] children = new String[][] { { } };

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
  .........................

  if(condition){
  children = populateChildren();
  }

  .........................
  }


  @Override
public void onSaveInstanceState(Bundle savedInstanceState) {
    if (groups != null && children != null) {
        savedInstanceState.putStringArray("Groups", groups);
        savedInstanceState.putSerializable("Children", children);       
    }
    super.onSaveInstanceState(savedInstanceState);
}

  @Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
    if (savedInstanceState != null) {
        groups = savedInstanceState.getStringArray("Groups");
        children = (String[][]) savedInstanceState
                .getSerializable("Children");
    }
    super.onRestoreInstanceState(savedInstanceState);
}

我得到了以下 java.lang.ClassCastException 异常。

01-19 17:12:55.417：E/AndroidRuntime(708)：原因：java.lang.RuntimeException：无法启动活动 ComponentInfo{com.abc.myapp/com.abc.myapp.mylistActivity}：java.lang。 ClassCastException：[Ljava.lang.Object；

01-19 17:12:55.417: E/AndroidRuntime(708): 在 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)

01-19 17:12:55.417: E/AndroidRuntime(708): 在 android.app.ActivityThread.startActivityNow(ActivityThread.java:2503)

01-19 17:12:55.417: E/AndroidRuntime(708): 在 android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)

01-19 17:12:55.417: E/AndroidRuntime(708): 在 android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)

01-19 17:12:55.417: E/AndroidRuntime(708): 在 android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)

01-19 17:12:55.417: E/AndroidRuntime(708): 在 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)

01-19 17:12:55.417: E/AndroidRuntime(708): ... 11 更多 01-19 17:12:55.417: E/AndroidRuntime(708): 由: java.lang.ClassCastException: [Ljava.lang 。目的; 01-19 17:12:55.417: E/AndroidRuntime(708): 在 com.abc.myapp.mylistActivity.onRestoreInstanceState(JobInfo.java:303)

01-19 17:12:55.417: E/AndroidRuntime(708): 在 android.app.Activity.performRestoreInstanceState(Activity.java:815)

01-19 17:12:55.417: E/AndroidRuntime(708): 在 android.app.Instrumentation.callActivityOnRestoreInstanceState(Instrumentation.java:1096)

01-19 17:12:55.417: E/AndroidRuntime(708): 在 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2641)

01-19 17:12:55.417: E/AndroidRuntime(708): ... 19 更多

有没有办法存储和检索多维数组？

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0 回答 0