通過putExtra（）傳遞自書面方式對象

Question

我想一個selfwritten對象Data.class的「數據」穿越到新創建的活動「SettingsScreen」與主活動「Mainscreen」

數據：

public class Data implements Serializable 
{ 
    private String ende; 
    private String anfang; 
    private String protocol; 
    private String URLkomplett; 

    private String username; 
    private String password; 

    private String manufacturer; 
    private String type; 
    private String productNr; 
    private String RFID; 

    private int scanArt; 

    private SharedPreferences prefs; 
    private MainScreen main; 
    private Editor edit; 
    private ConnectivityManager connManager; 
} 

方法MainScreen：

public void optionsButton(View v) 
{ 
    Intent intent = new Intent(this, SettingsScreen.class); 
    intent.putExtra("data", data); // IT CRASHES HERE, data Object is NOT NULL 
    startActivity(intent); 
} 

最後SettingsScreen的OnCreate法：

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_settings_screen); 
    data = (Data) getIntent().getSerializableExtra("data"); 
} 

這裏是logcat的輸出：

05-14 09:35:04.040: E/Trace(1623): error opening trace file: No such file or directory (2) 
05-14 09:35:04.340: D/dalvikvm(1623): GC_FOR_ALLOC freed 41K, 9% free 7256K/7939K, paused 65ms, total 66ms 
05-14 09:35:04.370: I/dalvikvm-heap(1623): Grow heap (frag case) to 9.017MB for 1536016-byte allocation 
05-14 09:35:04.560: D/dalvikvm(1623): GC_CONCURRENT freed <1K, 8% free 8755K/9479K, paused 87ms+3ms, total 190ms 
05-14 09:35:04.680: D/dalvikvm(1623): GC_FOR_ALLOC freed 0K, 8% free 8755K/9479K, paused 27ms, total 27ms 
05-14 09:35:04.690: I/dalvikvm-heap(1623): Grow heap (frag case) to 10.169MB for 1209856-byte allocation 
05-14 09:35:04.870: D/dalvikvm(1623): GC_CONCURRENT freed 0K, 8% free 9936K/10695K, paused 125ms+3ms, total 175ms 
05-14 09:35:05.100: D/libEGL(1623): loaded /system/lib/egl/libEGL_emulation.so 
05-14 09:35:05.191: D/(1623): HostConnection::get() New Host Connection established 0x2a13f270, tid 1623 
05-14 09:35:05.223: D/libEGL(1623): loaded /system/lib/egl/libGLESv1_CM_emulation.so 
05-14 09:35:05.230: D/libEGL(1623): loaded /system/lib/egl/libGLESv2_emulation.so 
05-14 09:35:05.401: W/EGL_emulation(1623): eglSurfaceAttrib not implemented 
05-14 09:35:05.410: D/OpenGLRenderer(1623): Enabling debug mode 0 
05-14 09:35:07.715: W/EGL_emulation(1623): eglSurfaceAttrib not implemented 
05-14 09:35:10.301: D/AndroidRuntime(1623): Shutting down VM 
05-14 09:35:10.301: W/dalvikvm(1623): threadid=1: thread exiting with uncaught exception (group=0x40a13300) 
05-14 09:35:10.401: E/AndroidRuntime(1623): FATAL EXCEPTION: main 
05-14 09:35:10.401: E/AndroidRuntime(1623): java.lang.IllegalStateException: Could not execute method of the activity 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.view.View$1.onClick(View.java:3591) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.view.View.performClick(View.java:4084) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.view.View$PerformClick.run(View.java:16966) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.os.Handler.handleCallback(Handler.java:615) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.os.Handler.dispatchMessage(Handler.java:92) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.os.Looper.loop(Looper.java:137) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.app.ActivityThread.main(ActivityThread.java:4745) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.lang.reflect.Method.invokeNative(Native Method) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.lang.reflect.Method.invoke(Method.java:511) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at dalvik.system.NativeStart.main(Native Method) 
05-14 09:35:10.401: E/AndroidRuntime(1623): Caused by: java.lang.reflect.InvocationTargetException 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.lang.reflect.Method.invokeNative(Native Method) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.lang.reflect.Method.invoke(Method.java:511) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.view.View$1.onClick(View.java:3586) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  ... 11 more 
05-14 09:35:10.401: E/AndroidRuntime(1623): Caused by: java.lang.RuntimeException: Parcelable encountered IOException writing serializable object (name = com.test.app.Data) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.os.Parcel.writeSerializable(Parcel.java:1279) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.os.Parcel.writeValue(Parcel.java:1233) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.os.Parcel.writeMapInternal(Parcel.java:591) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.os.Bundle.writeToParcel(Bundle.java:1619) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.os.Parcel.writeBundle(Parcel.java:605) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.content.Intent.writeToParcel(Intent.java:6470) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.app.ActivityManagerProxy.startActivity(ActivityManagerNative.java:1741) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.app.Instrumentation.execStartActivity(Instrumentation.java:1411) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.app.Activity.startActivityForResult(Activity.java:3351) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.app.Activity.startActivityForResult(Activity.java:3312) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.app.Activity.startActivity(Activity.java:3522) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.app.Activity.startActivity(Activity.java:3490) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at com.test.app.MainScreen.optionsButton(MainScreen.java:140) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  ... 14 more 
05-14 09:35:10.401: E/AndroidRuntime(1623): Caused by: java.io.NotSerializableException: android.net.ConnectivityManager 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.io.ObjectOutputStream.writeNewObject(ObjectOutputStream.java:1364) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.io.ObjectOutputStream.writeObjectInternal(ObjectOutputStream.java:1671) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:1517) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:1481) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.io.ObjectOutputStream.writeFieldValues(ObjectOutputStream.java:979) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:368) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.io.ObjectOutputStream.writeHierarchy(ObjectOutputStream.java:1074) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.io.ObjectOutputStream.writeNewObject(ObjectOutputStream.java:1404) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.io.ObjectOutputStream.writeObjectInternal(ObjectOutputStream.java:1671) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:1517) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:1481) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  at android.os.Parcel.writeSerializable(Parcel.java:1274) 
05-14 09:35:10.401: E/AndroidRuntime(1623):  ... 26 more 
05-14 09:35:12.700: I/Process(1623): Sending signal. PID: 1623 SIG: 9 

Answer 1

爲了Serialiable類必須：

1. 實現Serializable接口
2. 類內的每個成員必須實現Serializable

如果這兩個要求不符合你的課程不能序列化。

在你的情況private ConnectivityManager connManager;沒有實現Serializable所以它不能被序列化。這是造成例外。如果你想保持你的類裏面，你想序列化類可以加瞬態keyoword

private transient ConnectivityManager connManager; 

Answer 2

java.io.NotSerializableException：android.net.ConnectivityManager

你有一個類型爲android.net.ConnectivityManager的實例成員。反思。使其瞬變，使其成爲按需獲取的局部變量，刪除它，繼續使您的應用程序繼續工作。但是你不能'序列化它們。

Answer 3

好的，我想出了一個簡單的解決方案。我給我的SettignsScreen.class一個靜態變量Data，我從MainScreen初始化後，Activity已經開始。