c# - Android - 在 ListView 项目点击时打开开关 "On"

Question

我的 C# Android 应用程序中有一个自定义 ListView ，每一行都包含一个 textview、ImageView 和一个 switch。单击 Listview 项目时，我想打开该行的项目开关。

主要 Activity :

List<TableList> list = = new List<TableList>();
list.Add(new TableList("Germany"));
list.Add(new TableList("France"));
list.Add(new TableList("Finland"));
listView.ItemClick += delegate (object sender, AdapterView.ItemClickEventArgs e)
        {
            string selected = t.Name;
            if (selected == "France")
            {
                 // Turn the proper switch for France row ON
            }
        };

ListView 的 ListAdapter 和 ListClass:

public class ListAdapter : BaseAdapter<TableList>
{
    List<TableList> items;
    Activity context;
    public ListAdapter(Activity context, List<TableList> items)
        : base()
    {
        this.context = context;
        this.items = items;
    }
    public override long GetItemId(int position)
    {
        return position;
    }
    public override TableList this[int position]
    {
        get { return items[position]; }
    }
    public override int Count
    {
        get { return items.Count; }
    }
    public override View GetView(int position, View convertView, ViewGroup parent)
    {
        var item = items[position];
        View view = convertView;
        if (view == null) // no view to re-use, create new
            view = context.LayoutInflater.Inflate(Resource.Layout.CoinList, null);
        view.FindViewById<TextView>(Resource.Id.CoinName).Text = item.Name;
         view.FindViewById<ImageView>(Resource.Id.imageView1).SetImageResource(Resource.Drawable.n);

        If item is clicked set it on
        {
            view.FindViewById<Switch>(Resource.Id.switch).SetOn 
        }
        else
        {
            view.FindViewById<Switch>(Resource.Id.switch).SetOf
        }
        return view;
    }
}
public class TableList
{
    public string Name;
    public TableList(string Name)
    {
        this.Name = Name;
    }
}

我不知道应该在哪里设置 Switch ON(在 listView.ItemClick 事件中或在 ListAdapter 中)并且我不知道如何设置它打开。请帮助我这样做。

Answer 1

Here是我的演示。

您可以选择一个来实现您的目标。我将向您展示如何通过 ItemClick 事件执行此操作:

When a Listview item is clicked, I want to turn the row's item switch on.

因为，Switch 会从 ViewGroup 中获取焦点。因此，我将焦点从 MyAdapter 中的 Switch 移开:

holder.ms.Focusable = false;//ms is Switch

现在，这是我的 ItemClick 事件(点击项目时打开开关):

private void MListView_ItemClick(object sender, AdapterView.ItemClickEventArgs e)
{
        var ll = e.View as LinearLayout;
        var sw = ll.GetChildAt(1) as Switch;
        if (sw.Checked)
        {
            sw.Checked = false;
            adapter.changeState((int)sw.Tag,false);
        }
        else
        {
            sw.Checked = true;
            adapter.changeState((int)sw.Tag, true);
        }
}

众所周知，ListView存在重用问题，所以，我添加了一个bool属性来控制Switch的状态:

public class MyData:Java.Lang.Object {
    public MyData(string p,bool b) {
        this.position = p;
        this.isCheck = b;
    }
    public string position { get; set; }
    public bool isCheck { get; set; }
}

下面是changeState方法:

internal void changeState(int position, bool v)
{
    mitems[position].isCheck = v;
    this.NotifyDataSetChanged();
}

这是 CheckedChange 事件:

private void Ms_CheckedChange(object sender, CompoundButton.CheckedChangeEventArgs e)
{
    var sm = sender as Switch;
    Log.Error("Ms_CheckedChange", (int)sm.Tag+"");
    if (e.IsChecked&&!mitems[(int)sm.Tag].isCheck)
    {
        mitems[(int)sm.Tag].isCheck = true;
        this.NotifyDataSetChanged();
    }
    else if(!e.IsChecked&& mitems[(int)sm.Tag].isCheck)
    {
        mitems[(int)sm.Tag].isCheck = false;
        this.NotifyDataSetChanged();
    }

}