In WinForm, when we trying to set a value for Text property of a TextBox control that run in another thread, we can use code like this:

 

int totalFileNumbers = ReturnTotalFiles() ;

delegate_SetBarMaximum del_SetMax = 

new delegate_SetBarMaximum ( SetProgressBar_Maximum );

Invoke ( del_SetMax , 

new Object [] { totalFileNumbers });

 

 

but we will found that the Invoke will not work in WPF. I read an article in the net and found that in WPF we should use tb_Time.Dispatcher.Invoke:

Sample:

 

XAML:

 

<

Window 

x:Class

="Sample_InvokeInWPF.MainWindow"

        xmlns

="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

        xmlns:x

="http://schemas.microsoft.com/winfx/2006/xaml"

        Title

="MainWindow"

 Height

="350"

 Width

="525"

>

    

<

Grid 

ShowGridLines

="False"

 Height

="300"

 Width

="480"

 

>

        

<

Grid.RowDefinitions

>

            

<

RowDefinition 

x:Name

="row1"

 Height

="50"

/>

            

<

RowDefinition 

x:Name

="row2"

 Height

="50"

/>

            

<

RowDefinition 

x:Name

="row3"

 Height

="50"

/>

        

</

Grid.RowDefinitions

>

        

<

Grid.ColumnDefinitions

>

            

<

ColumnDefinition 

x:Name

="col1"

 Width

="200"

/>

            

<

ColumnDefinition 

x:Name

="col2"

/>

        

</

Grid.ColumnDefinitions

>

        

<

TextBlock 

Text

="Region"

 Grid.Row

="2"

 Grid.Column

="0"

 HorizontalAlignment

="Right"

 VerticalAlignment

="Center"

 FontFamily

="Tahoma"

 FontSize

="16"

 

/>

        

<

TextBlock 

Text

="Current Time"

 Grid.Row

="1"

 Grid.Column

="0"

 HorizontalAlignment

="Right"

 VerticalAlignment

="Center"

 FontFamily

="Tahoma"

 FontSize

="16"

/>

        

<

ComboBox 

x:Name

="cb_TimeToShow"

 Grid.Row

="2"

 Grid.Column

="1"

 FontFamily

="Tahoma"

 FontSize

="16"

 Text

="GMT"

  

>

            

<

ComboBoxItem 

Content

="UTC"

 FontFamily

="Tahoma"

 FontSize

="16"

 HorizontalAlignment

="Right"

 

/>

            

<

ComboBoxItem 

Content

="GMT"

 FontFamily

="Tahoma"

 FontSize

="16"

 HorizontalAlignment

="Right"

/>

        

</

ComboBox

>

       

        

<

TextBox 

x:Name

="tb_Time"

 Grid.Row

="1"

 Grid.Column

="1"

 BorderThickness

="10"

>

            

<

TextBox.BorderBrush 

>

                

<

LinearGradientBrush 

>

                    

<

GradientStop 

Color

="Black"

 Offset

="0"

/>

                    

<

GradientStop 

Color

="#FF30EB95"

 Offset

="1"

/>

                

</

LinearGradientBrush

>

            

</

TextBox.BorderBrush

>

        

</

TextBox

>

        

        

<

Button 

x:Name

="bt_StartNewThread"

 Content

="Start Process of Displaying Time"

 Grid.Column

="0"

 Grid.Row

="0"

 Grid.ColumnSpan

="2"

 FontFamily

="Tahoma"

 FontSize

="16"

 Click

="bt_StartNewThread_Click"

 

/>

    

</

Grid

>

</

Window

>

CS Code:

 

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

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;

namespace Sample_InvokeInWPF

{

    

delegate 

void delegate_ShowTime();

    

delegate 

void delegate_RunAnotherThread();

    

///

 

<summary>

    

///

 Interaction logic for MainWindow.xaml

    

///

 

</summary>

    

public 

partial 

class MainWindow : Window

    {

        

public MainWindow()

        {

            InitializeComponent();

        }

        

private 

void bt_StartNewThread_Click(

object sender, RoutedEventArgs e)

        {

            delegate_RunAnotherThread del_newThread = 

new delegate_RunAnotherThread(RunNewThread);

            del_newThread.BeginInvoke(

new AsyncCallback(return_Result), del_newThread);

        }

        

void return_Result(IAsyncResult ar)

        {

            delegate_RunAnotherThread del_newThread = (delegate_RunAnotherThread)ar.AsyncState;

            del_newThread.EndInvoke(ar);

        }

        

void RunNewThread()

        {

            

//

This is the Current Thread that is running

            

while (

true)

            {

                

//

Get cb_TimeToShow Text value

                

string region = 

string.Empty;

                cb_TimeToShow.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Normal, 

new Action(

delegate()

                {

                    region = cb_TimeToShow.Text.Trim();

                }));

                

if (region == 

string.Empty)

                {

                    MessageBox.Show(

"

Select one Region in Comobox

");

                    

return;

                }

                

string StrTime = String.Empty;

                

if (region == 

"

GMT

")

                    StrTime = System.DateTime.Now.Hour.ToString() + 

"

 H 

" + System.DateTime.Now.Minute.ToString() + 

"

 Min 

" + System.DateTime.Now.Second.ToString() + 

"

 Second 

";

                

else 

if (region == 

"

UTC

")

                    StrTime = System.DateTime.UtcNow.Hour.ToString() + 

"

 H 

" + System.DateTime.UtcNow.Minute.ToString() + 

"

 Min 

" + System.DateTime.UtcNow.Second.ToString() + 

"

 Second 

";

                

//

Set tb_Time Text value

                tb_Time.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Normal, 

new Action(

delegate()

                {

                    tb_Time.Text = StrTime;

                }));

            }

        }

    }

}