How to get Items selected

[EDGAR GARCIA]

Hi, how to get values from SFCombobox and send it to HttpClient. I need save values into Mysql Database.

My XAML:

<?xml version="1.0" encoding="UTF-8" ?>

<ContentPage

xmlns="http://xamarin.com/schemas/2014/forms"

xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"

xmlns:combobox="clr-namespace:Syncfusion.XForms.ComboBox;assembly=Syncfusion.SfComboBox.XForms"

xmlns:local="clr-namespace:MVP.ViewModels" xmlns:inputLayout="clr-namespace:Syncfusion.XForms.TextInputLayout;assembly=Syncfusion.Core.XForms"

x:Class="MVP.Pages.ConsoleMessages"

Title="Console">

<ContentPage.BindingContext>

<local:ViewModelGroup/>

</ContentPage.BindingContext>

<ContentPage.Content>

<StackLayout>

<StackLayout>

<Label Text="Users">

<combobox:SfComboBox

x:Name="valoresObtenidos"

MultiSelectMode="Token"

DisplayMemberPath="Quien_Nombre"

SelectedValue="{Binding SelectedValue, Mode=TwoWay}"

SelectedValuePath="Quien_ID"

IsEditableMode="True"/>

</StackLayout>

<StackLayout>

<Button

x:Name="ConsolaMsg_BtnSend"

Text="Send"

Clicked="BotonEnviarMensaje"/>

</StackLayout>

</StackLayout>

</ContentPage.Content>

</ContentPage>

Code Behind:

using System;

using System.Collections.Generic;

using System.Net.Http;

using MVP.Modelos;

using Newtonsoft.Json;

using Xamarin.Forms;

namespace MVP.Pages

{

public partial class ConsoleMessages : ContentPage

{

private List<ModeloQuienes> modeloQuienesDatos;

public ConsoleMessages()

{

InitializeComponent();

}

private void ComboBox_SelectionChanged(object sender, Syncfusion.XForms.ComboBox.SelectionChangedEventArgs e)

{

string jsonResultados = string.Empty;

try

{

HttpClient Cliente = new HttpClient();

Cliente.BaseAddress = new Uri("http://www.mvppro.us");

string url = string.Format("/xamarin/json_loadusers.php");

var resultado = await Cliente.GetAsync(url);

jsonResultados = resultado.Content.ReadAsStringAsync().Result;

}

catch (Exception)

{

await DisplayAlert("Error", "Your Smartphone Should Be Connected to Internet", "Ok");

return;

}

modeloQuienesDatos = JsonConvert.DeserializeObject<List<ModeloQuienes>>(jsonResultados);

valoresObtenidos.DataSource = modeloQuienesDatos;

UserDialogs.Instance.HideLoading();

}

// SEND SFCOMBOBOX

private async void BotonEnviarMensaje(System.Object sender, System.EventArgs e)

{

// CODE HERE

}

}

}

Thanks and appreciate your help !!

[Suganya Sethuraman]

Hi EDGAR,

Greetings from Syncfusion.

We have analyzed your query. We recommend that you use the SelectedItem API of SfComboBox to retrieve the selected item of SfComboBox.

Code snippet 

        private void Button_Clicked(object sender, EventArgs e) 

        { 

                                           var selectedItems = cmbFavList.SelectedItem; 

        } 

 

Please have a sample for your reference,

Sample: https://www.syncfusion.com/downloads/support/directtrac/general/ze/ComboBoxSample885644423

Please check if the sample satisfies your requirement and let us know if you have any concerns.

Regards,
Suganya Sethuraman. 

[EDGAR GARCIA]

thanks, but your sample not working. check it.

when. i add this line:

private async void Button_Clicked(object sender, EventArgs e)

{

var selectedItems = cmbFavList.SelectedItem;

await DisplayAlert("", selectedItems.ToString(),"");

}

Crash the app

[Fernando]

Try it: await DisplayAlert("Alert", selectedItems.ToString(),"OK");

Display alert cant be empty

Then change to

if ( cmbFavList .SelectedItem != null)

            {

                string value = ( cmbFavList  .SelectedItem as YourModel). Quien_ID ;

             }

[EDGAR GARCIA]

thanks Fernando, but not working.

the code:

if(valoresObtenidos.SelectedItem != null)

{

    var value = (valoresObtenidos.SelectedItem as ModeloQuienes).Quien_ID;

    await DisplayAlert("test", Value, "Ok");

}

 Crash 

[EDGAR GARCIA]

using the same example:

private async void Button_Clicked(object sender, EventArgs e)

{

    if (cmbFavList.SelectedItem != null)

    {

        string value = (cmbFavList.SelectedItem as Employee).Name;

        await DisplayAlert("Alert", value, "OK");

    }

}

i received this message: 

System.NullReferenceException has been thrown

[Suganya Sethuraman]

Hi EDGAR,

Sorry for the inconvenience.

We would like to let you know that in SfComboBox's Token mode, we can get the SelectedItem as an ObservableCollection<object>. So, using the code snippet below, you can get the SelectedItem.

Code snippet 

        private void Button_Clicked(object sender, EventArgs e) 

        { 

            ObservableCollection<object> tempCollection = new ObservableCollection<object>(); 

            if (cmbFavList.SelectedItem is ObservableCollection<object>) 

            { 

                tempCollection = cmbFavList.SelectedItem as ObservableCollection<object>; 

            } 

        } 

Please check and let us know if you have any concerns.

Regards,
Suganya Sethuraman. 

[EDGAR GARCIA]

ok, but how can i Access Value From ObservableCollection in this example?

        private void Button_Clicked(object sender, EventArgs e)

        {

            ObservableCollection<object> tempCollection = new ObservableCollection<object>();

            if (cmbFavList.SelectedItem is ObservableCollection<object>)

            {

                tempCollection = cmbFavList.SelectedItem as ObservableCollection<object>;

                DisplayAlert("Selected Items", tempCollection.ToString(), "Ok");

            }

        }

DisplayAlert show this when Button_Clicked is pressed : 

system.collections.objectmodel.ObservableCollection

i would like show the names or values selected.

Thanks.

[EDGAR GARCIA]

???? Any solution ?

[Suganya Sethuraman]

Hi EDGAR,

We would like to let you know that in SfComboBox's Token mode, we can get the SelectedValue as List<string>. So, using the code snippet below, you can get and display the selected value.

Code snippet  

        private void Button_Clicked(object sender, EventArgs e) 

        { 

                                           List<string> tempCollection = new List<string>(); 

            if (cmbFavList.SelectedValue is List<string>) 

            { 

                tempCollection = cmbFavList.SelectedValue as List<string>; 

            } 

 

            var result = string.Join(", ", tempCollection); 

                                           DisplayAlert("Selected Items", result, "Ok"); 

                             } 

Please check and let us know if you have any concerns.

Regards,
Suganya Sethuraman. 

[EDGAR GARCIA]

Am dissapointed, I have tried everything. Can you check the code attached ?

When i clicked so return empty list. Please check it 

Attachment: Archive_b4037b96.zip

[Ruba Shanmugam]

Hi EDGAR,

Greetings from Syncfusion.

We have validated your query and we will update the complete details on or before the Nov 10, 2021. We appreciate your patience until then.

Regards,
Ruba Shanmugam

[EDGAR GARCIA]

Ok. Am waiting your response. appreciate your help.

Kind Regards,

Edgar

[Suganya Sethuraman]

Hi EDGAR,

Sorry for the inconvenience. 

We have modified the sample based on your requirement. Please have a sample for your reference,

Code snippet: 

                             private void Button_Clicked(object sender, EventArgs e) 

                             { 

                                           List<string> tempCollection = new List<string>(); 

                                            

                                           if (employeeViewModel.FooObject is ObservableCollection<object>) 

                                           { 

                                                          for (int i = 0; i < (employeeViewModel.FooObject as ObservableCollection<object>).Count; i++) 

                                                          { 

                                                                        tempCollection.Add(((employeeViewModel.FooObject as ObservableCollection<object>)[i] as Employee).Name); 

                                                          } 

                                           } 

 

                                           var result = string.Join(", ", tempCollection); 

                                           DisplayAlert("Selected Items", result, "Ok"); 

                             } 

Sample:  https://www.syncfusion.com/downloads/support/directtrac/general/ze/SfComboBox2020161405

Please check and let us know if you have any concerns.

Regards,
Suganya Sethuraman. 

[EDGAR GARCIA]

Great !!!!! Thanks, that works for me !!

[Suganya Sethuraman]

Hi EDGAR,

Thanks for the update.

We are glad that your issue is resolved. Please let us know if you require any further assistance.

Regards,
Suganya Sethuraman.