单击图像按钮 xamarin 时显示选择器

Question

我想在单击 imageButton 时显示一个选择器（或列表），但它不起作用，但是当我只创建一个选择器时，它起作用了。

Xaml

     <StackLayout Orientation="Horizontal" x:Name="stacklayout">
                <Entry Placeholder="préciser l'entité correspondante" 
                       ClearButtonVisibility="WhileEditing" x:Name="entit"/>

                <ImageButton Source="list.png" WidthRequest="30" HeightRequest="30" x:Name="listEntité" Clicked="listEntité_Clicked"/>

Xaml.cs

 private void listEntité_Clicked(object sender, EventArgs e)
    {

               Picker p = new Picker();
              HttpClient httpClient = new HttpClient();
              httpClient.BaseAddress = new Uri("http://192.168.1.3:3000/api/adepApi/GetCurrencyLists");
              httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
              HttpResponseMessage response = await httpClient.GetAsync("http://192.168.1.3:3000/api/adepApi/GetCurrencyLists");
              var content = await response.Content.ReadAsStringAsync();
              ResponseDataD EL = JsonConvert.DeserializeObject<ResponseDataD>(content);
              p.ItemsSource= EL.Data.DeviseList;
              stacklayout.Children.Add(p.ItemsSource);


          }

类设计模型

  public class DeviseModel
{
    public class DeviseL
    {
     //   public string devis;
        [JsonProperty("Label")]

        public string Devis { get; set; }
        [JsonProperty("Value")]

        public int id { get; set; }


    }
    public class ResponseDataD
    {
        public RootModelDevise Data;
    }
    public class RootModelDevise : INotifyPropertyChanged
    {

        List<DeviseL> deviseList;

        [JsonProperty("list")]
        public List<DeviseL> DeviseList
        {
            get { return deviseList; }
            set
            {
                if (deviseList != value)
                {
                    deviseList = value;
                    OnPropertyChanged();
                }
            }
        }
        DeviseL itemDevise;
        public DeviseL ItemDevise
        {
            get { return itemDevise; }
            set
            {
                if (itemDevise != value)
                {
                    itemDevise = value;
                    OnPropertyChanged();
                }
            }
        }
        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = "")
        {

            var changed = PropertyChanged;
            if (changed == null)
                return;
            changed.Invoke(this, new PropertyChangedEventArgs(propertyName));               
   }
}}

我在行中有错误 stacklayout.Children.Add(p.ItemsSource); 在 p.itemsSource 下：无法从 'System.Collections.Ilist' 转换为 'Xamarin.Forms.View'

Answer 1

我尝试通过 imageButton 点击​​事件添加选择器，但没有出现。

首先，请确认EL.Data.DeviseList有list值，你有list绑定到Picker，然后将picker添加到当前contentPage。

public partial class Page16 : ContentPage
{
    private List<string> list;
    public Page16()
    {
        InitializeComponent();
        list = new List<string>();

        list.Add("test 1");
        list.Add("test 2");
        list.Add("test 3");
        list.Add("test 4");

    }

    private void imagebutton1_Clicked(object sender, EventArgs e)
    {
        Picker p = new Picker();
        p.ItemsSource = list;
        stacklayout.Children.Add(p);
    }
}

 <StackLayout x:Name="stacklayout">
        <ImageButton
            x:Name="imagebutton1"
            Clicked="imagebutton1_Clicked"
            HeightRequest="30"
            Source="plu3.png"
            WidthRequest="30" />

    </StackLayout>

更新：

 private void imagebutton1_Clicked(object sender, EventArgs e)
    {
        Picker p = new Picker();
        p.SelectedIndexChanged += P_SelectedIndexChanged;
        p.ItemsSource = devs;     
        p.ItemDisplayBinding = new Binding("Devis");

        stacklayout.Children.Add(p);
    }

    private void P_SelectedIndexChanged(object sender, EventArgs e)
    {
        Picker p = sender as Picker;
        DeviseL selectitem = p.SelectedItem as DeviseL;
        entit.Text =selectitem.Devis;
    }