无法保存 RelativeLayout 的状态

Question

我正在制作一个具有 activity 的应用程序，用户可以在其中向对象添加图片，在这里我让用户选择是从图库中选择图片还是使用相机。这两个选项都会启动一个 Intent（在用户完成选择图片后）returns 到 activity 它来自。

但我遇到的问题是，当用户回来时，有时 activity 的一些数据会丢失，所以我 "reload" 它使用 savedInstance。我尝试保存的对象之一是扩展 RelativeLayout 的自定义视图的数组列表。但是当我加载以下数据时，出现以下错误：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.sition.projectmanager/com.example.sition.projectmanager.activities.ObjectActivity}: java.lang.RuntimeException: Parcelable encountered IOException reading a Serializable object (name = com.example.sition.projectmanager.TabButton)
           at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2262)
           at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2316)
           at android.app.ActivityThread.access0(ActivityThread.java:158)
           at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1296)
           at android.os.Handler.dispatchMessage(Handler.java:99)
           at android.os.Looper.loop(Looper.java:176)
           at android.app.ActivityThread.main(ActivityThread.java:5365)
           at java.lang.reflect.Method.invokeNative(Native Method)
           at java.lang.reflect.Method.invoke(Method.java:511)
           at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
           at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.RuntimeException: Parcelable encountered IOException reading a Serializable object (name = com.example.sition.projectmanager.TabButton)
           at android.os.Parcel.readSerializable(Parcel.java:2144)
           at android.os.Parcel.readValue(Parcel.java:2016)
           at android.os.Parcel.readListInternal(Parcel.java:2235)
           at android.os.Parcel.readArrayList(Parcel.java:1655)
           at android.os.Parcel.readValue(Parcel.java:1986)
           at android.os.Parcel.readMapInternal(Parcel.java:2226)
           at android.os.Bundle.unparcel(Bundle.java:223)
           at android.os.Bundle.getParcelable(Bundle.java:1173)
           at android.app.Activity.onCreate(Activity.java:930)
           at com.example.sition.projectmanager.activities.ObjectActivity.onCreate(ObjectActivity.java:102)
           at android.app.Activity.performCreate(Activity.java:5326)
           at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1097)
           at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2225)
           at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2316) 
           at android.app.ActivityThread.access0(ActivityThread.java:158) 
           at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1296) 
           at android.os.Handler.dispatchMessage(Handler.java:99) 
           at android.os.Looper.loop(Looper.java:176) 
           at android.app.ActivityThread.main(ActivityThread.java:5365) 
           at java.lang.reflect.Method.invokeNative(Native Method) 
           at java.lang.reflect.Method.invoke(Method.java:511) 
           at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)               at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869) 
           at dalvik.system.NativeStart.main(Native Method) 
Caused by: java.io.InvalidClassException: android.widget.RelativeLayout; IllegalAccessException
           at java.io.ObjectStreamClass.resolveConstructorClass(ObjectStreamClass.java:692)
           at java.io.ObjectStreamClass.newInstance(ObjectStreamClass.java:653)
           at java.io.ObjectInputStream.readNewObject(ObjectInputStream.java:1826)
           at java.io.ObjectInputStream.readNonPrimitiveContent(ObjectInputStream.java:787)
           at java.io.ObjectInputStream.readObject(ObjectInputStream.java:2013)
           at java.io.ObjectInputStream.readObject(ObjectInputStream.java:1970)
           at android.os.Parcel.readSerializable(Parcel.java:2142)
           at android.os.Parcel.readValue(Parcel.java:2016) 
           at android.os.Parcel.readListInternal(Parcel.java:2235) 
           at android.os.Parcel.readArrayList(Parcel.java:1655) 
           at android.os.Parcel.readValue(Parcel.java:1986) 
           at android.os.Parcel.readMapInternal(Parcel.java:2226) 
           at android.os.Bundle.unparcel(Bundle.java:223) 
           at android.os.Bundle.getParcelable(Bundle.java:1173) 
           at android.app.Activity.onCreate(Activity.java:930) 
           at com.example.sition.projectmanager.activities.ObjectActivity.onCreate(ObjectActivity.java:102) 
           at android.app.Activity.performCreate(Activity.java:5326) 
           at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1097) 
           at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2225) 
           at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2316) 
           at android.app.ActivityThread.access0(ActivityThread.java:158) 
           at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1296) 
           at android.os.Handler.dispatchMessage(Handler.java:99) 
           at android.os.Looper.loop(Looper.java:176) 
           at android.app.ActivityThread.main(ActivityThread.java:5365) 
           at java.lang.reflect.Method.invokeNative(Native Method) 
           at java.lang.reflect.Method.invoke(Method.java:511) 
           at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869) 
           at dalvik.system.NativeStart.main(Native Method)

这是我自定义的 RelativeLayout Class:

public class TabButton extends RelativeLayout implements Serializable {
    public TabButton(Context context) {
         super(context);
    }

    public TabButton(Context context, AttributeSet attrs) {
         super(context, attrs);
    }

    public TabButton(Context context, AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);
    }
}

还有我的 onSaveInstanceState 和 onRestoreInstanceState：

@Override
protected void onSaveInstanceState(Bundle outState) {
    outState.putSerializable("CURRENT_OBJECT",currentObject);
    outState.putSerializable("TAB_BUTTONS", tabButtons);
    super.onSaveInstanceState(outState);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);
    currentObject = (Objectable) savedInstanceState.getSerializable("CURRENT_OBJECT");
    tabButtons = (ArrayList<TabButton>) savedInstanceState.getSerializable("TAB_BUTTONS");
}

我做错了什么？

Answer 1

你的概念是错误的：你不应该保存整个小部件，而是重新创建它们的信息。

However, your activity might have more state information that you'd like to restore, such as member variables that track the user's progress in the activity.

来自：Android Activity Lifecycle, Android SDK Docs

因此将信息保存为整数（在您的示例中用于标识所选选项卡）或其他原语并设置在 onRestoreInstanceState 中。

无法保存 RelativeLayout 的状态

Can't save state of RelativeLayout

java

android

serializable

parcelable

android-savedstate