[英]Activity receives Null from Parcelable object
我正在使用可包裹的對象來傳遞意圖。 我的物件看起來像這樣
enter code here
public class Recipe實現Parcelable {private List recipe = null; 私有列表成分=空; 私有字符串准備;
public Recipe(List<String> recipe, List<String> ingredients,
String preparation) {
this.recipe = recipe;
this.ingredients = ingredients;
this.preparation = preparation;
}
public Recipe(Parcel source) {
source.readStringList(recipe);
source.readStringList(ingredients);
this.preparation = source.readString();
}
public List<String> getRecipe() {
return recipe;
}
public List<String> getIngredients() {
return ingredients;
}
public String getPreparation() {
return preparation;
}
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeStringList(recipe);
dest.writeStringList(ingredients);
dest.writeString(preparation);
}
public static final Parcelable.Creator<Recipe> CREATOR = new Creator<Recipe>() {
@Override
public Recipe[] newArray(int size) {
return new Recipe[size];
}
@Override
public Recipe createFromParcel(Parcel source) {
return new Recipe(source);
}
};}
我這樣將數據放入Intent
enter code here @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_recipe);
dbMan = new XmlManager();
try {
db = dbMan.parse();
} catch (XmlPullParserException e) {
System.err.println("XmlPullParserException " + e.getMessage());
e.printStackTrace();
} catch (IOException e) {
System.err.println("IO Excepion " + e.getMessage());
e.printStackTrace();
}
// get the listview
expListView = (ExpandableListView) findViewById(R.id.expandableListView1);
// preparing list data
prepareListData();
listAdapter = new MyBaseExpandableListAdapter(this, listDataHeader,
listDataChild);
// setting list adapter
expListView.setAdapter(listAdapter);
// Listview on child click listener
expListView.setOnChildClickListener(new OnChildClickListener() {
@Override
public boolean onChildClick(ExpandableListView parent, View v,
int groupPosition, int childPosition, long id) {
sendChildList = listDataChild
.get(listDataHeader.get(groupPosition))
.get(childPosition).toString();
sendRecipe = dbMan.getRecipyByCriteria(db, sendChildList);
Toast.makeText(getApplicationContext(),
"sendet" + sendChildList, Toast.LENGTH_LONG).show();
Intent in = new Intent(getApplicationContext(),
ShowRecipe.class);
in.putExtra("sendRecipe", sendRecipe);
startActivity(in);
return false;
}
});
}
好吧,我調試了這部分代碼,並且我知道sendRecipe對象已實例化並且數據正確。 所以我把這個東西放到了意圖上並發送給下一個活動
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_show_recipe);
findeRecipe = (Recipe)getIntent().getParcelableExtra("sendRecipe");
在這個地方,Intent接收到NULL。 這很有趣,因為當我發送String或int時,它會正確接收。 我坐在場景現場調試這一天,閱讀有關Parcelable的問題,我所做的一切都正確,並且沒有任何正常工作。
可能的問題是您使用了應用程序上下文: Intent in = new Intent(getApplicationContext()...
改為嘗試傳遞活動。
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