【发布时间】:2014-06-06 09:19:46
【问题描述】:
我想用我创建的 Parcelable 类将数据发送到 Fragment。
我知道这就是您在使用 Activity 时的处理方式(ObjectA 是扩展 Parcelable 的类):
ObjectA obj = new ObjectA();
// Set values etc.
Intent i = new Intent(this, MyActivity.class);
i.putExtra("com.package.ObjectA", obj);
startActivity(i);
但由于您不能对 Fragments 使用 Intent,所以我不知道该怎么做。
我什至可以使用 Parcelable 类吗?如果没有,我应该使用什么?我有可能,怎么做?
编辑/更新:
我已根据您的建议进行了更新,但仍然没有得到所有信息。
这是我们用来创建列表视图的片段:
package com.tsjd.HotMeals;
import java.util.ArrayList;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;
import com.example.tabtest.R;
public class RecipeListViewFragment extends Fragment {
ArrayList<String> titles;
ArrayList<String> descriptions;
ArrayList<String> images;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
RecipeListViewParcer object = getArguments().getParcelable("extraObject");
titles = object.getTitles();
descriptions = object.getDescriptions();
images = object.getImages();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_recipelistview, container,
false);
final ListView listview = (ListView) v.findViewById(R.id.listview);
RecipeListViewAdapter adapter = new RecipeListViewAdapter(
getActivity(), titles);
listview.setAdapter(adapter);
return v;
}
public void onListItemClick(ListView l, View v, int position, long id) {
// do something with the data
}
}
我想将这个 ListView 用于不同的事情,所以我希望能够将三个 ArrayList 发送给它。为此,我创建了一个实现 Parcelable 的类,就是这样:
package com.tsjd.HotMeals;
import java.util.ArrayList;
import android.os.Parcel;
import android.os.Parcelable;
public class RecipeListViewParcer implements Parcelable{
private ArrayList<String> titles;
private ArrayList<String> descriptions;
private ArrayList<String> images;
@SuppressWarnings("unchecked")
private RecipeListViewParcer(Parcel in) {
titles = (ArrayList<String>) in.readSerializable();
descriptions = (ArrayList<String>) in.readSerializable();
images = (ArrayList<String>) in.readSerializable();
}
public int describeContents() {
return 0;
}
public ArrayList<String> getTitles()
{
return titles;
}
public void setTitles(ArrayList<String> titles){
this.titles = titles;
}
public ArrayList<String> getDescriptions()
{
return descriptions;
}
public void setDescriptions(ArrayList<String> descriptions){
this.descriptions = descriptions;
}
public ArrayList<String> getImages()
{
return images;
}
public void setImages(ArrayList<String> images){
this.images = images;
}
public void writeToParcel(Parcel out, int flags) {
out.writeSerializable(titles);
out.writeSerializable(descriptions);
out.writeSerializable(images);
}
public static final Parcelable.Creator<RecipeListViewParcer> CREATOR
= new Parcelable.Creator<RecipeListViewParcer>() {
public RecipeListViewParcer createFromParcel(Parcel in) {
return new RecipeListViewParcer(in);
}
public RecipeListViewParcer[] newArray(int size) {
return new RecipeListViewParcer[size];
}
};
}
最后,这是一个Fragment,它使用listview来显示最喜欢的菜谱,这里我要发送三个ArrayList,这是目前唯一有错误的代码。我不知道如何为我的 Parcelable 类的构造函数声明我需要的 Parcel,我应该怎么做? (我还没有在我的 ArrayLists 中放任何东西,但我希望这个想法很清楚)。
package com.tsjd.HotMeals;
import java.util.ArrayList;
import android.os.Bundle;
import android.os.Parcel;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
public class MyRecipesFragment extends Fragment {
ArrayList<String> titles = new ArrayList<String>();
ArrayList<String> descriptions = new ArrayList<String>();
ArrayList<String> images = new ArrayList<String>();
Parcel in = new Parcel();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
Fragment fragment = new RecipeListViewFragment();
RecipeListViewParcer obj = new RecipeListViewParcer(in);
obj.setDescriptions(descriptions);
obj.setTitles(titles);
obj.setImages(images);
Bundle bundle = new Bundle();
bundle.putParcelable("extraObject", obj);
fragment.setArguments(bundle);
fragmentTransaction.commit();
}
}
【问题讨论】:
-
使用 bundle 并设置到片段
-
尝试调试,
RecipeListViewParcer(Parcel in)构造函数方法中收到了什么?
标签: java android android-intent android-fragments parcelable