Android Parcelable - Write and read ArrayList< IA > when IA is a interface

落花浮王杯 提交于 2019-11-30 00:50:54

问题


I have a interface IA and class B and C that implement them. Both B and C implement Parcelable as well.

Then I have the tricky part:

Class D has a ArrayList< IA >. I need this too insert both classes B and C in the arraylist. They share the same structure but the "IS-A" relation don't apply.

I need to pass D from one activity to another as a Parcel.

I've tried to write (ArrayList<IA>) in.readSerializable but I got a IOException. I know that if IA was not a interface the problem was easy, but I can't seem to find an easy solution for this.

Any ideas?

@SuppressWarnings("unchecked")
public D (Parcel in) {
    list = new ArrayList<IA>();
    (...)    
    list = (ArrayList<IA>) in.readSerializable 
    }

@SuppressWarnings("rawtypes")
public static final Parcelable.Creator CREATOR =
new Parcelable.Creator() {
    public D createFromParcel(Parcel in) {
        return new D(in);
    }

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

public int describeContents() {
    return 0;
}

public void writeToParcel(Parcel dest, int flags) {
    (...)
    dest.writeList(list);
}

回答1:


    @SuppressWarnings("unchecked")
public D (Parcel in) {
    list = new ArrayList<IA>();
    (...)    
    //ERROR -> list = (ArrayList<IA>) in.readSerializable 
    list = in.readArrayList(IA.class.getClassLoader());
}

@SuppressWarnings("rawtypes")
public static final Parcelable.Creator CREATOR =
new Parcelable.Creator() {
    public D createFromParcel(Parcel in) {
        return new D(in);
    }

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

public int describeContents() {
    return 0;
}

public void writeToParcel(Parcel dest, int flags) {
    (...)
    dest.writeList(list);
}



回答2:


I recommend you to install "Android Parcelable code generator" plugin. After this you can generate writeToParcel function, constructor which reads from parcel and creator class only whith clicking Alt+Insert buttons.



来源:https://stackoverflow.com/questions/15543924/android-parcelable-write-and-read-arraylist-ia-when-ia-is-a-interface

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