java - 通过使用parcelable，尝试将一个数组列表添加到另一个数组列表中，出现错误 "the method add is not applicable for the arguments"

Question

我有一个 Activity (第一个 Activity ):

ArrayList <MyDouble> myfinals=new ArrayList <MyDouble>();
...
i.putParcelableArrayListExtra("myfinals",myfinals);
...
 public static class MyDouble implements Parcelable {
            Double al;


            public MyDouble(Parcel source){
                al = source.readDouble();
            }

            public MyDouble(Double val){
                al = val;
            }

            @Override
            public int describeContents() {
                // TODO Auto-generated method stub
                return this.hashCode();
            }

            @Override
            public void writeToParcel(Parcel dest, int flags) {
                // TODO Auto-generated method stub
                dest.writeDouble(al);

            }

            public Double getValueDouble(){
                return this.al;
            }
            public static final Parcelable.Creator<MyDouble> CREATOR = new Parcelable.Creator<MyDouble>() {

                @Override
                public MyDouble createFromParcel(Parcel source) {
                    // TODO Auto-generated method stub
                    return new MyDouble(source);
                }

                @Override
                public MyDouble[] newArray(int size) {
                    // TODO Auto-generated method stub
                    return new MyDouble[size];
                }
            };

        }

在其他 Activity 中:

ArrayList <MyDouble> myfinals=new ArrayList <MyDouble>();
ArrayList<Double> y =new ArrayList<Double>();
...
 for (int i=0;i<=100;i++){
          y.add(myfinals.get(i)); 

       } 

我正在尝试将“myfinals”添加到 y 但它给了我错误“添加方法不适用于参数'firstactivity.MyDouble”。

Answer 1

这应该有效:

for (int i=0;i<=100;i++){
    y.add(myfinals.get(i).getValueDouble()); 
}