Text Box and Combo box binding

Mohammed Hablullah

8y1k

I need a logic to implement

let consider only two controls textbox and combobox with 4 option.

Option 1 multiply by 1

Option 2 multiply by 2

Option 3 multiply by 3

Option 4 multiply by 4

for example user enters 1000 in the textbox and select option 2 in combobox.

the value 2000 (which is 1000 x 2) should display in the same text box.

When the user again changes the option in combobox with option 3.

the value to result in the text box as 3000 (i.e, 1000x3) it should not take the current value in the text box for calculation.. it should take the user entered value.

4 Replies

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Rafnas T P8y ago
Accepted answer
Hi, You can do like following, First declare one global variable let say Double userValue=0; Next in text box text change event assign textbox value to this variable. Like userValue=Convert.ToDouble(txt1.Text); Next in drop-down box selected index change event you can write txt1.Text=userValue*Convert.ToDouble(drpdownvalue.Value)
Pawan Kumar Tiwari8y ago
You can use selectedvalue in case of selectedindex and apply same logic
Mohammed Hablullah8y ago
Dear Mr.Rafnas,

I am getting Input String format is not correct error..

Please refer my code below,
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using Kruger;
using Fan.Airflow;
using Fan.ViewModel;
namespace Fan
{
///

/// Interaction logic for MainWindow.xaml
///
public partial class MainWindow : Window
{
public double airflowvol = 0;
public MainWindow()
{
InitializeComponent();
}
private void RadioButton_ImageFailed(object sender, ExceptionRoutedEventArgs e)
{
}
private void Button_Click(object sender, RoutedEventArgs e)
{
Window1 w = new Window1();
w.Show();
}
public void Air_input(object sender, TextChangedEventArgs e)
{
airflowvol = Convert.ToDouble(Volume.Text);
}
private void AirFlowUnit_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if(AirFlowUnit.SelectedIndex==0)
{
Volume.Text = Convert.ToString(airflowvol * 1);
}
else if(AirFlowUnit.SelectedIndex==1)
{
Volume.Text = Convert.ToString(airflowvol * 1.7);
}
else if (AirFlowUnit.SelectedIndex == 2)
{
Volume.Text = Convert.ToString(airflowvol * 0.00028);
}
else if (AirFlowUnit.SelectedIndex == 3)
{
Volume.Text = Convert.ToString(airflowvol * 1000);
}
}
}
}
Mohammed Hablullah8y ago
Dear Rafnas,

Thanks for your reply. Can you explain me the syntax "Convert.ToDouble(drpdownvalue.Value)"

also i have loaded the data to combobox item from xml. Then how can i assign values to each data. Like first data of four data in combobox is CFM which is equal to a value of 1 and second is CMH which is equal to 1.7 like wise it goes. Please help me out.