Question

我制作了一个可以绘制的自定义视图，并将该图形保存到arraylist中。我想将这些数组列表保存在onSaveInstanceState中，并在onRestoreInstanceState中检索它们。我已经尝试过将Sharedpreferences与Json结合使用，但它无法正常工作甚至无法打包。我要保存路径和绘画。

笔类：

 private static class Pen implements Parcelable {
    Path path;
    Paint paint;
    int color;
    float width;
    Pen(int colort, float widtht ) {
        color = colort;
        width = widtht;
        path = new Path();
        paint = new Paint();
        paint.setAntiAlias(true);
        paint.setStrokeWidth(width);
        paint.setColor(color);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeJoin(Paint.Join.ROUND);
        paint.setStrokeCap(Paint.Cap.ROUND);
    }
    // De-parcel Pen object
    public Pen(Parcel in) {
        color = in.readInt();
        width = in.readFloat();
        path = new Path();
        paint = new Paint();
        paint.setAntiAlias(true);
        paint.setStrokeWidth(width);
        paint.setColor(color);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeJoin(Paint.Join.ROUND);
        paint.setStrokeCap(Paint.Cap.ROUND);
    }


    // Function that writes Dice values to parcel
    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeInt(color);
        dest.writeFloat(width);
    }


    // Creator of Parcelable
    public static final Parcelable.Creator CREATOR = new Parcelable.Creator()  {

        public Pen createFromParcel(Parcel in) {
            return new Pen(in);
        }

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


    // Function to implement Parcelable interface
    @Override
    public int describeContents() {
        return 0;
    }

}

OnsaveInstanceState：

@Override
public Parcelable onSaveInstanceState()
 {
     Bundle bundle = new Bundle();
     bundle.putParcelable("superState", super.onSaveInstanceState());
     bundle.putParcelableArrayList("pen", mPenList);
     return bundle;
}

onRestoreInstanceState：

@Override
    public void onRestoreInstanceState(Parcelable state)
    {

        if (state instanceof Bundle) // implicit null check
        {
            Bundle bundle = (Bundle) state;
            this.mPenList = bundle.getParcelableArrayList("pen");
            state = bundle.getParcelable("superState");

        }
        super.onRestoreInstanceState(state);

    }

Answer 1

 @Override
protected void onSaveInstanceState(Bundle outState) {
    // Save the state so that next time we know if we need to refresh data.
    outState.putParcelableArrayList("yourkey",yourlist);
  );
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);
   list= savedInstanceState.getParcelableArrayList("yourkey");
}

也许这可以帮助您：）

保存和还原自定义数组，最小化

1 个答案: