通过以下代码将数据从一个活动传递给其他活动：
@Override
public void execute(List<Report> reports,Questions question) {
Intent replyIntent = new Intent(listener,ReplyActivity.class);
replyIntent.putExtra("id",0L);
replyIntent.putExtra("questions",question);
listener.openReportOk(question);
listener.startActivity(replyIntent);
}
监听其回调的活动引用.
问题是这个类：
@Table(name = "Questions")
public class Questions extends Entity implements Parcelable {
public static final Creator<Questions> CREATOR = new Creator<Questions>() {
public Questions createFromParcel(Parcel source) {
return new Questions(source);
}
public Questions[] newArray(int size) {
return new Questions[size];
}
};
@TableField(name = "idReport",datatype = DATATYPE_INTEGER)
private int idReport;
@TableField(name = "nameReport",datatype = DATATYPE_STRING)
private String nameReport;
@TableField(name = "replyGroups",datatype = DATATYPE_STRING)
private String replyGroups;
@TableField(name = "questionGroups",datatype = DATATYPE_ENTITY)
private List<QuestionsGroup> questionsGroup;
private Boolean canCreateNew;
public Questions(int idReport,String nameReport,String replyGroups,List<QuestionsGroup> questionsGroup) {
this.idReport = idReport;
this.nameReport = nameReport;
this.replyGroups = replyGroups;
this.questionsGroup = questionsGroup;
this.canCreateNew = false;
}
public Questions() {
questionsGroup = new ArrayList<QuestionsGroup>();
}
private Questions(Parcel in) {
this();
this.idReport = in.readInt();
this.nameReport = in.readString();
this.replyGroups = in.readString();
Bundle b = in.readBundle(QuestionsGroup.class.getClassLoader());
this.questionsGroup = b.getParcelableArrayList("questionGroups");
this.canCreateNew = (Boolean) in.readValue(Boolean.class.getClassLoader());
}
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest,int flags) {
dest.writeInt(this.idReport);
dest.writeString(this.nameReport);
dest.writeString(this.replyGroups);
Bundle b = new Bundle();
b.putParcelableArrayList("questionGroups",(ArrayList<QuestionsGroup>) this.questionsGroup);
dest.writeBundle(b);
dest.writeValue(this.canCreateNew);
}
}
当我在onCreate方法中收到包裹时：
private void getData(Intent data) {
ID = data.getExtras().getLong("id");
questions = data.getExtras().getParcelable("questions");
}
我得到这个错误：
10-05 13:19:15.508 3499-3499/com.firext.android E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.firext.android,PID: 3499
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.firext.android/com.firext.android.activities.reply.ReplyActivity}: java.lang.IllegalStateException: Bad magic number for Bundle: 0x28
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2255)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2317)
at android.app.ActivityThread.access$800(ActivityThread.java:143)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1258)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5070)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:836)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:631)
Caused by: java.lang.IllegalStateException: Bad magic number for Bundle: 0x28
at android.os.BaseBundle.readFromParcelInner(BaseBundle.java:1342)
at android.os.BaseBundle.<init>(BaseBundle.java:90)
at android.os.Bundle.<init>(Bundle.java:66)
at android.os.Parcel.readBundle(Parcel.java:1645)
at com.firext.android.domain.QuestionsGroup.<init>(QuestionsGroup.java:53)
at com.firext.android.domain.QuestionsGroup$1.createFromParcel(QuestionsGroup.java:25)
at com.firext.android.domain.QuestionsGroup$1.createFromParcel(QuestionsGroup.java:23)
at android.os.Parcel.readParcelable(Parcel.java:2160)
at android.os.Parcel.readValue(Parcel.java:2066)
at android.os.Parcel.readListInternal(Parcel.java:2422)
at android.os.Parcel.readArrayList(Parcel.java:1756)
at android.os.Parcel.readValue(Parcel.java:2087)
at android.os.Parcel.readArrayMapInternal(Parcel.java:2393)
at android.os.BaseBundle.unparcel(BaseBundle.java:221)
at android.os.Bundle.getParcelableArrayList(Bundle.java:782)
at com.firext.android.domain.Questions.<init>(Questions.java:58)
at com.firext.android.domain.Questions.<init>(Questions.java:18)
at com.firext.android.domain.Questions$1.createFromParcel(Questions.java:22)
at com.firext.android.domain.Questions$1.createFromParcel(Questions.java:20)
at android.os.Parcel.readParcelable(Parcel.java:2160)
at android.os.Parcel.readValue(Parcel.java:2066)
at android.os.Parcel.readArrayMapInternal(Parcel.java:2393)
at android.os.BaseBundle.unparcel(BaseBundle.java:221)
at android.os.Bundle.getParcelable(Bundle.java:738)
at com.firext.android.activities.reply.ReplyActivity.getData(ReplyActivity.java:72)
at com.firext.android.activities.reply.ReplyActivity.onCreate(ReplyActivity.java:38)
at android.app.Activity.performCreate(Activity.java:5720)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1102)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2208)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2317)
at android.app.ActivityThread.access$800(ActivityThread.java:143)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1258)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5070)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:836)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:631)
怎么了？
解决方法
概要
看起来你有一个错误,你如何存储&检索问题组的混合信息.第53行是要注意的一行.
当写入包裹时,Android会在每个字段中存储一个特殊的“魔术数字”,以确保在将字段从包裹中拉出时使用正确的顺序(请参阅号码定义的详细说明).
您收到错误,因为在预期的位置找不到魔术数字 – 这是因为您没有以正确的顺序将字段从包裹中取出.
官方源代码的详细解释
[下面的解释是基于“最新的”(在撰写本文时)API21实现的Bundle和BaseBundle类.您可以在这里找到完整的代码：
> BaseBundle on android.googlesource.com
您还可以使用Android SDK Manager将代码的本地副本安装到开发机器上,我觉得非常有用. ]
所以…
当包裹写入时,Android会采取一些安全措施,以确保在尝试对其进行不分开时,这些字段将排列起来.为此,Android将字段附加到“魔术数字”中,定义为：
static final int BUNDLE_MAGIC = 0x4C444E42; // 'B' 'N' 'D' 'L'
你可以在writeToParcelInner()的代码中看到这一点(总结如下)
void writeToParcelInner(Parcel parcel,int flags) {
if (mParcelledData != null) {
if (mParcelledData == EMPTY_PARCEL) {
parcel.writeInt(0);
} else {
int length = mParcelledData.dataSize();
parcel.writeInt(length);
parcel.writeInt(BUNDLE_MAGIC);
parcel.appendFrom(mParcelledData,length);
}
} else {
.......... extra code chopped out for illustration purposes
}
}
同样,当从包裹中读取时,Android会在返回包裹中的值之前检查该BUNDLE_MAGIC号码.
private void readFromParcelInner(Parcel parcel,int length) {
if (length == 0) {
// Empty Bundle or end of data.
mParcelledData = EMPTY_PARCEL;
return;
}
int magic = parcel.readInt();
if (magic != BUNDLE_MAGIC) {
//noinspection ThrowableInstanceNeverThrown
throw new IllegalStateException("Bad magic number for Bundle: 0x"
+ Integer.toHexString(magic));
}
.......... extra code chopped out for illustration purposes
}
在上述code for API21 BaseBundle中,您可以看到根据logcat跟踪在第1342行上抛出的错误.
解决方法进一步调试
原始海报指出,QuestionsGroup是正确包装.
进一步调试此问题的一种方法是远离引进BaseBundle类的(当前)新API21;例如,只使用Bundle类的API19.
如果用户的代码实际上是正确的,那么更有可能在更成熟的API上运行.
如果代码仍然中断,则可能是QuestionsGroup代码.但是,除此之外,新的logcat跟踪将指向代码的不同部分,可以查看并可能提供更多的洞察问题.
除了是Bundle,第1730行,方法readFromParcelInner(),这意味着同样的问题：
int magic = parcel.readInt();
if (magic != BUNDLE_MAGIC) {
//noinspection ThrowableInstanceNeverThrown
throw new IllegalStateException("Bad magic number for Bundle: 0x"
+ Integer.toHexString(magic));
}
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> Android parcelable and Intent: redBundle: bad magic number
