Błąd podczas przechodzenia przedmiotu z działalności do innego (Korzystanie Parcelable)

Question

próbowałem przekazać obiekt klasy z działalności do innego Korzystanie Parcelable

mam utworzyć klasę i nazwę go Student

package com.example.test08_passobjectoverintent; 

import android.os.Parcel; 
import android.os.Parcelable; 

public class Student implements Parcelable 
{ 

    private String st_AcadimicNumber ; 
    private String st_Name ; 
    private String st_Class ; 
    public String getSt_AcadimicNumber() { 
     return st_AcadimicNumber; 
    } 
    public void setSt_AcadimicNumber(String st_AcadimicNumber) { 
     this.st_AcadimicNumber = st_AcadimicNumber; 
    } 
    public String getSt_Name() { 
     return st_Name; 
    } 
    public void setSt_Name(String st_Name) { 
     this.st_Name = st_Name; 
    } 
    public String getSt_Class() { 
     return st_Class; 
    } 
    public void setSt_Class(String st_Class) { 
     this.st_Class = st_Class; 
    } 

    public Student(String st_AcadimicNumber, String st_Name, String st_Class) { 
     super(); 
     this.st_AcadimicNumber = st_AcadimicNumber; 
     this.st_Name = st_Name; 
     this.st_Class = st_Class; 
    } 
public Student() { 
    super(); 
} 
    @Override 
    public int describeContents() { 
     // TODO Auto-generated method stub 
     return 0; 
    } 

    @Override 
    public void writeToParcel(Parcel dest, int flags) { 
     // TODO Auto-generated method stub 

    } 

} 

W głównej działalności używam tego kodu, aby zdać Obejct ...

   Student st = new Student("aaa","bbb","ccc"); 
       Intent intent = new Intent(MainActivity.this,Main2Activity.class); 
       intent.putExtra("stu", st); 
       startActivity(intent); 

w drugim Aktywny (Retrieve One)

mogę użyć tego kodu (błąd jest TUTAJ)

Student model = (Student)getIntent().getParcelableExtra("stu"); 

LogCat Błąd

12-09 15:50:06.068: E/Trace(30655): error opening trace file: No such file or directory (2) 
12-09 15:50:06.188: D/libEGL(30655): loaded /system/lib/egl/libEGL_mali.so 
12-09 15:50:06.188: D/libEGL(30655): loaded /system/lib/egl/libGLESv1_CM_mali.so 
12-09 15:50:06.193: D/libEGL(30655): loaded /system/lib/egl/libGLESv2_mali.so 
12-09 15:50:06.193: D/(30655): Device driver API match 
12-09 15:50:06.193: D/(30655): Device driver API version: 10 
12-09 15:50:06.193: D/(30655): User space API version: 10 
12-09 15:50:06.193: D/(30655): mali: REVISION=Linux-r2p4-02rel0 BUILD_DATE=Wed Sep 12 17:53:53 KST 2012 
12-09 15:50:06.218: D/OpenGLRenderer(30655): Enabling debug mode 0 
12-09 15:50:08.033: D/GestureDetector(30655): [Surface Touch Event] mSweepDown False, mLRSDCnt : -1 mTouchCnt : 4 mFalseSizeCnt:0 
12-09 15:50:08.123: D/AndroidRuntime(30655): Shutting down VM 
12-09 15:50:08.123: W/dalvikvm(30655): threadid=1: thread exiting with uncaught exception (group=0x40e372a0) 
12-09 15:50:08.128: E/AndroidRuntime(30655): FATAL EXCEPTION: main 
12-09 15:50:08.128: E/AndroidRuntime(30655): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.test08_passobjectoverintent/com.example.test08_passobjectoverintent.Main2Activity}: android.os.BadParcelableException: Parcelable protocol requires a Parcelable.Creator object called CREATOR on class com.example.test08_passobjectoverintent.Student 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2100) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2125) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.app.ActivityThread.access$600(ActivityThread.java:140) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1227) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.os.Handler.dispatchMessage(Handler.java:99) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.os.Looper.loop(Looper.java:137) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.app.ActivityThread.main(ActivityThread.java:4898) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at java.lang.reflect.Method.invokeNative(Native Method) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at java.lang.reflect.Method.invoke(Method.java:511) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1008) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:775) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at dalvik.system.NativeStart.main(Native Method) 
12-09 15:50:08.128: E/AndroidRuntime(30655): Caused by: android.os.BadParcelableException: Parcelable protocol requires a Parcelable.Creator object called CREATOR on class com.example.test08_passobjectoverintent.Student 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.os.Parcel.readParcelable(Parcel.java:2086) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.os.Parcel.readValue(Parcel.java:1965) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.os.Parcel.readMapInternal(Parcel.java:2226) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.os.Bundle.unparcel(Bundle.java:223) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.os.Bundle.getParcelable(Bundle.java:1165) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.content.Intent.getParcelableExtra(Intent.java:4451) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at com.example.test08_passobjectoverintent.Main2Activity.onCreate(Main2Activity.java:22) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.app.Activity.performCreate(Activity.java:5191) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094) 
12-09 15:50:08.128: E/AndroidRuntime(30655): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2064) 
12-09 15:50:08.128: E/AndroidRuntime(30655): ... 11 more 

Answer 1

trzeba zaimplementować kod do zapisu i odczytu swoich pól klasy od działki.

W writeToParcel:

@Override 
public void writeToParcel(Parcel dest, int flags) { 
     dest.writeString(st_AcadimicNumber); 
     dest.writeString(st_Name); 
     dest.writeString(st_Class); 
} 

działki Autor:

public static final Parcelable.Creator<Track> CREATOR 
= new Parcelable.Creator<Track>() { 
    public Student createFromParcel(Parcel in) { 
     return new Track(in); 
    } 

    public Student[] newArray(int size) { 
     return new Track[size]; 
    } 
}; 

A konstruktor:

public Student (Parcel source){ 
     /* 
     * Reconstruct from the Parcel. Keep same order as in writeToParcel() 
     */ 
     st_AcadimicNumber = source.readString(); 
     st_Name = source.readString(); 
     st_Class = source.readString(); 
} 

i gotowe.

Pozdrowienia