Question

我在Listview中创建了一个复选框。但是，当我关闭应用程序并重新打开时，它不会保存我列出的项目的状态。

然而，这对我没有用，我似乎无法找到如何解决这个问题的答案。如果有人可以帮助我完成ListAdapter Activty的代码，如下所示，我们将不胜感激。

public class ListAdapter extends BaseAdapter {
Context ctx;
LayoutInflater lInflater;
ArrayList<Product> objects;

ListAdapter(Context context, ArrayList<Product> products) {
    ctx = context;
    objects = products;
    lInflater = (LayoutInflater) ctx
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

@Override
public int getCount() {
    return objects.size();
}

@Override
public Object getItem(int position) {
    return objects.get(position);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View view = convertView;
    if (view == null) {
        view = lInflater.inflate(R.layout.item, parent, false);
    }

    Product p = getProduct(position);

    ((TextView) view.findViewById(R.id.tvDescr)).setText(p.name);
    ((TextView) view.findViewById(R.id.tvPrice)).setText(p.price + "");
    ((ImageView) view.findViewById(R.id.ivImage)).setImageResource(p.image);

    CheckBox cbBuy = (CheckBox) view.findViewById(R.id.cbBox);
    cbBuy.setOnCheckedChangeListener(myCheckChangList);
    cbBuy.setTag(position);
    cbBuy.setChecked(p.box);
    return view;
}

Product getProduct(int position) {
    return ((Product) getItem(position));
}

ArrayList<Product> getBox() {
    ArrayList<Product> box = new ArrayList<Product>();
    for (Product p : objects) {
        if (p.box)
            box.add(p);
    }
    return box;
}

OnCheckedChangeListener myCheckChangList = new OnCheckedChangeListener() {
    public void onCheckedChanged(CompoundButton buttonView,
                                 boolean isChecked) {
        getProduct((Integer) buttonView.getTag()).box = isChecked;
    }
};
}

我不确定我做错了什么，或者我把它放错了地方，或者整个代码是不正确的。

这是使用共享偏好设置的已编辑解决方案版本：

public class ListAdapter extends BaseAdapter {
Context ctx;
LayoutInflater lInflater;
ArrayList<Product> objects;

ListAdapter(Context context, ArrayList<Product> products) {
    ctx = context;
    objects = products;
    lInflater = (LayoutInflater) ctx
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

@Override
public int getCount() {
    return objects.size();
}

@Override
public Object getItem(int position) {
    return objects.get(position);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View view = convertView;
    if (view == null) {
        view = lInflater.inflate(R.layout.item, parent, false);
    }

   final Product p = getProduct(position);

    ((TextView) view.findViewById(R.id.tvDescr)).setText(p.name);
    ((TextView) view.findViewById(R.id.tvPrice)).setText(p.price + "");
    ((ImageView) view.findViewById(R.id.ivImage)).setImageResource(p.image);

    final CheckBox cbBuy = (CheckBox) view.findViewById(R.id.cbBox);
    SharedPreferences settings  = ctx.getSharedPreferences("data",ctx.MODE_PRIVATE);
    boolean Checked = settings.getBoolean(p.name, false);
    cbBuy.setChecked(Checked);



    cbBuy.setOnCheckedChangeListener(new OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            if(cbBuy.isChecked()==true){
                SharedPreferences settings = ctx.getSharedPreferences("data",Context.MODE_PRIVATE);
                settings.edit().putBoolean(p.name, true).commit();
                Toast.makeText(ctx, "You Selected" + p.name, Toast.LENGTH_SHORT).show();

            }else{
                SharedPreferences settings = ctx.getSharedPreferences("data", Context.MODE_PRIVATE);
                settings.edit().putBoolean(p.name, false).commit();
                Toast.makeText(ctx, "You Deselected" +p.name, Toast.LENGTH_SHORT).show();

            }
        }
    });{

        return view;

    }

}

Answer 1

字段不是永久存储。如果要在启动期间保留数据，则必须将其保存在关闭状态并在启动时加载。

ListView保存已选中状态

1 个答案: