Question

我尝试使用intent和putExtras（）使用此代码将自定义类从活动传递到另一个活动：

public class MyFirstActivity extends ListActivity {

String selectedItem = "selectedItem";
String[] allItemNames;
CustomClass[] allItems = null;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.list_all_items);


    allItems = createItemsMethod(); //IsTooLongToPost


    CustomClass item = new CustomClass();
    String[] allItemNames = getAllTheNamesMethod(); //IsTooLongToPost


    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
            R.layout.show_item_in_row, R.id.textview_item_row, allItemNames);


    ListView listView = (ListView) findViewById(android.R.id.list);
    listView.setAdapter(adapter);
}

@Override
public void onListItemClick(ListView l, View v, int position, long id) {

    // Do something when a list item is clicked
    super.onListItemClick(l, v, position, id);

    String value = (String) getListView().getItemAtPosition(position);


    Intent intent = new Intent(this, MySecondActivity.class);
    Item currentItem = allItems[position];
    Bundle b = new Bundle();
    b.putParcelable("Key", currentItem);
    intent.putExtras(b);

    startActivity(intent);
}}

这个意图中的值是可以的，但是当我尝试将它们带入我的其他活动时，意图为空并且Extras不在那里，我的其他活动有这个代码：

public class MySecondActivity extends Activity {


protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.show_activity);
}

protected void onStart() {
    super.onStart();
    Intent i = getIntent();
    Bundle b = getIntent().getExtras();

    if(b!=null){
        CustomClass item = b.getParcelable("Key");
    }
}}

这是CustomClass

public class CustomClass implements Parcelable{

String name;
int id;
String description;
LinkedList<CustomClass> related;

String[] itemList;

// Other costructors and getters

public CustomClass(Parcel parcel) {
    name = parcel.readString();
    id = parcel.readInt();
    description = parcel.readString();
    related = null;

}

// Parcel Part

@Override
public int describeContents() {
    return 0;
}

@Override
public void writeToParcel(Parcel parcel, int i) {
    parcel.writeString(name);
    parcel.writeInt(id);
    parcel.writeString(description);
    parcel.writeTypedList(related);
}

public static Creator<CustomClass> CREATOR = new Creator<CustomClass>() {
    public CustomClass createFromParcel(Parcel parcel) {
        return new CustomClass(parcel);
    }

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

任何想法为什么会发生这种情况？感谢

Answer 1

您需要在类Anime中实现Parcelable并添加未实现的方法请点击此链接了解如何实施它 https://github.com/pilhuhn/ZwitscherA/blob/master/src/de/bsd/zwitscher/account/Account.java

Answer 2

您可以将对象从一个活动传递到另一个活动，根据我的知识，您可以使用两种方法。一个是使你的Bean（类） Parcelable ，其他简单的方法是使它 Serializable 。

使用Serializable 假设您要传递此类的对象

public class CustomClass implements Serializable{
    //put your class member variable here and it's getters and setters
    }

然后从你的第一个活动开始，

Intent intent = new Intent(this, MySecondActivity.class);
//get the object of CustomClass which you want to pass
// let's say it's name is **customClassObject**

//Now pass it to the second activity
intent.putExtra(Intent.EXTRA_TEXT,clickedMenuItemBean);
startActivity(intent);

现在进入第二个Activity.获取Custom类的pass对象意图。

CustomClass cc = (CustomClass) intent.getSerializableExtra(Intent.EXTRA_TEXT);

在第二个Activity中没有得到正确的Intent

2 个答案: