I have an ArrayList of custom FlightData objects within the intent. I load the intent and get the arraylist as null, and the foreach loop also forces me to use Object
as type.
Saving arraylist into intent:
intent.putParcelableArrayListExtra("FlightDataList", (ArrayList<? extends Parcelable>) flightDataList);
Loading of intent:
Intent intent = getIntent();
LinearLayout layout_datasheet = findViewById(R.id.layout_datasheet);
List flightDataList = intent.getParcelableArrayListExtra("FlightDataList");
if (flightDataList == null){
Log.d("flightDataList_size", "FlightDataList is null"); // this fires
}
assert flightDataList != null;
for (Object data : flightDataList){
data = (FlightData) data; // items in list are of type FlightData
TextView tv = new TextView(this);
tv.setText(data.toString());
layout_datasheet.addView(tv);
}
My custom class' parcelable functions (x,y,time, has getters-setters):
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeDouble(x);
dest.writeDouble(y);
dest.writeDouble(time);
}
public static final Creator<FlightData> CREATOR = new Creator<FlightData>() {
@Override
public FlightData createFromParcel(Parcel in) {
return new FlightData(in);
}
@Override
public FlightData[] newArray(int size) {
return new FlightData[size];
}
};
1.First Implement Parceable in your FlightData object model / pojo / class
2. val flightDataList= ArrayList<FlightData>()
3. val args = Bundle()
4. args.putParcelableArrayList("FlightDataList", flightDataList)
5. intent.putExtra(args)
Then to get list
val flightDataList = context.getIntent().getExtras().getParcelableArrayList("FlightDataList")
I doubt that you have implemented Parcable in FlightData https://medium.com/techmacademy/how-to-implement-and-use-a-parcelable-class-in-android-part-1-28cca73fc2d1
did you try creating a datastructure that implements parcelable?
public class flightDataList implements Parcelable{
String dataThingyString;
int dataThingyInt;
public flightDataList(String dataThingyString, int dataThingyInt){
this.dataThingyString = dataThingyString;
this.dataThingyInt = dataThingyInt;
}
public flightDataList(Parcle in){
this.dataThingyString = in.readString();
this.dataThingyInt = in.readInt();
}
@Override
public void writeToParcel(Parcel dest, int flags){
dest.writeString(dataThingyString);
dest.writeInt(dataThingyInt);
}
public static final Creator<flightDataList> CREATOR = new Creator<flightDataList>(){
@Override
public flightDataList createFromParcel(Parcel source){
return new flightDataList(source);
}
@Override
public flightDataList[] newArray(int size){
return new flightDataList[size];
}
}
public void setdataThingyString(String stringData){
this.dataThingyString = stringData;
}
public void setdataThingyInt(int intData){
this.dataThingyInt = intData;
}
public String getdataThingyString(){
return dataThingyString;
}
public int getdataThingyInt(){
return dataThingyInt;
}
@Override
public int describeContents(){
return 0;
}
}
It should work. The only thing that I am missing in your example is the constructor. It could explain the null
your are getting.
Try adding this constructor for FlightData
public FlightData(Parcel in) {
x = in.readDouble();
y = in.readDouble();
time = in.readDouble();
}
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