Question

尝试使用visual studio在xamarin android中单击图像时显示和隐藏（切换）列表视图。但它没有隐藏。我在这里做错了什么。 onclick我无法隐藏并显示listview.below是我的onclick代码

 protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            SetContentView(Resource.Layout.HomeScreen);
            listView = FindViewById<ListView>(Resource.Id.List);

            tableItems.Add(new TableItem() { Heading = "Vegetables", SubHeading = "65 items", ImageResourceId = Resource.Drawable.Vegetables });
            tableItems.Add(new TableItem() { Heading = "Fruits", SubHeading = "17 items", ImageResourceId = Resource.Drawable.Fruits });

            listView.Adapter = new HomeScreenAdapter(this, tableItems);

            listView.ItemClick += OnListItemClick;

            ImageView ImageView = FindViewById<ImageView>(Resource.Id.imageView1);
            //  ListView listView = FindViewById<ListView>(Resource.Id.List);

            ImageView.FindViewById<ImageView>(Resource.Id.imageView1).Click += (object sender, System.EventArgs e) =>
            {
                listView.FindViewById<ListView>(Resource.Id.List).Visibility = Android.Views.ViewStates.Visible;
            };


        }

        protected void OnListItemClick(object sender, Android.Widget.AdapterView.ItemClickEventArgs e)
        {
            var listView = sender as ListView;
            var t = tableItems[e.Position];
            Android.Widget.Toast.MakeText(this, t.Heading, Android.Widget.ToastLength.Short).Show();
            Console.WriteLine("Clicked on " + t.Heading);
        }

我是android和xamarin的新bie.Any帮助表示赞赏。

Answer 1

这是错误的......

 ImageView ImageView = FindViewById<ImageView>(Resource.Id.imageView1);

 ImageView.FindViewById<ImageView>(Resource.Id.imageView1).Click += (object sender, System.EventArgs e) =>
 {
     listView.FindViewById<ListView>(Resource.Id.List).Visibility = Android.Views.ViewStates.Visible;
 };

您在第一行中获得对图像视图的引用，但随后在该视图上执行FindViewById以获取子视图。除非你将ImageView嵌套在另一个ImageView中，否则这不会起作用。

你很亲密。这应该没有看到你的布局......

 ImageView imageView = FindViewById<ImageView>(Resource.Id.imageView1);

 imageView.Click += (object sender, System.EventArgs e) =>
 {
     if (listView.Visibility == ViewStates.Visible)
        listView.Visibility = ViewStates.Invisible;
     else
        listView.Visibility = ViewStates.Visible;
 };

FindViewById是一个昂贵的电话。如果你不必这样做，尽量不要一遍又一遍。

在xamarin android中单击隐藏/显示列表视图时出现问题

1 个答案: