WPF Listview Getting row values

listviewwpf

I have XAML File as below:

<Window x:Class="ComboBoxCheck.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:check="clr-namespace:ComboBoxCheck"
Title="Window1" Height="300" Width="320">
<Window.Resources>
    <ObjectDataProvider x:Name="Designation" MethodName="GetDesignations" ObjectType="{x:Type check:Window1}" x:Key="Designation" IsAsynchronous="True"/>
</Window.Resources>
<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="*"/>
        <RowDefinition Height="30"/>
    </Grid.RowDefinitions>
    <ListView Grid.Row="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Name="lsvStaffList"  Margin="0,0,0,3"
          BorderBrush="Transparent" BorderThickness="0">
        <ListView.View>
            <GridView>
                <GridViewColumn Header="Employee Id" Width="70" DisplayMemberBinding="{Binding Path=EmployeeId}"/>
                <GridViewColumn Header="Employee Name" Width="90" DisplayMemberBinding="{Binding Path=EmployeeName}"/>
                <GridViewColumn Header="Designation" Width="120">
                    <GridViewColumn.CellTemplate>
                        <DataTemplate>
                            <ComboBox Name="cmbDesignation" Height="20" Width="90" SelectedValue="{Binding Path=EmployeeDesignation}"
                                      ItemsSource="{Binding Source={StaticResource Designation}}"
                                      DisplayMemberPath="Name" SelectedValuePath="Id"
                                      VerticalAlignment="Top" HorizontalAlignment="Stretch"/>        
                        </DataTemplate>
                    </GridViewColumn.CellTemplate>
                </GridViewColumn>                    
            </GridView>
        </ListView.View>
    </ListView>
    <Button Name="btnProperty" Width="75" Content="Get Value" Height="25" Click="btnProperty_Click" Grid.Row="1"/>
</Grid>

The code behind file is as below:

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 ComboBoxCheck
{

public partial class Window1 : Window
{
    public static Designations designations = null;
    public Employees employees = null;

    public Window1()
    {
        InitializeComponent();

        designations = new Designations();
        employees = new Employees();

        Designation d1 = new Designation();
        d1.Id = 1;
        d1.Name = "Manager";
        designations.Add(d1);

        Designation d2 = new Designation();
        d2.Id = 2;
        d2.Name = "Developer";
        designations.Add(d2);

        Designation d3 = new Designation();
        d3.Id = 3;
        d3.Name = "Lead";
        designations.Add(d3);

        Employee e1 = new Employee();
        e1.EmployeeId = 1;
        e1.EmployeeName = "Name1";
        e1.EmployeeDesignation = 2;
        employees.Add(e1);

        Employee e2 = new Employee();
        e2.EmployeeId = 2;
        e2.EmployeeName = "Name2";
        e2.EmployeeDesignation = 2;
        employees.Add(e2);

        Employee e3 = new Employee();
        e3.EmployeeId = 3;
        e3.EmployeeName = "Name3";
        e3.EmployeeDesignation = 1;
        employees.Add(e3);

        lsvStaffList.ItemsSource = employees;

    }

    public static Designations GetDesignations()
    {
        return designations;
    }

    private void btnProperty_Click(object sender, RoutedEventArgs e)
    {
        //I need something like this
        //Employees employeesCollection = new Employees();
        //employeesCollection[0].EmployeeId = 1
        //employeesCollection[0].EmployeeName = Name1
        //employeesCollection[0].EmployeeDesignation = Developer

        //employeesCollection[1].EmployeeId = 2
        //employeesCollection[1].EmployeeName = Name2
        //employeesCollection[1].EmployeeDesignation = Developer

        //employeesCollection[2].EmployeeId = 3
        //employeesCollection[2].EmployeeName = Name3
        //employeesCollection[2].EmployeeDesignation = Manager
    }

}

public class Designations : List<Designation> {}

public class Designation
{
    private int id;

    public int Id
    {
        get { return id; }
        set { id = value; }
    }
    private string name;

    public string Name
    {
        get { return name; }
        set { name = value; }
    }

}

public class Employees : List<Employee> { }

public class Employee
{
    private int employeeid;

    public int EmployeeId
    {
        get { return employeeid; }
        set { employeeid = value; }
    }
    private string employeename;

    public string EmployeeName
    {
        get { return employeename; }
        set { employeename = value; }
    }
    private int employeedesignation;

    public int EmployeeDesignation
    {
        get { return employeedesignation; }
        set { employeedesignation = value; }
    }
}

}

I would like to get the employees collection which has employee name, employee id and employee designation. I need a code in the click event of 'Get Value' button and given the format.

Best Answer

Your bindings work fine. Just get the Items collection of your ListView like this:

private void btnProperty_Click(object sender, RoutedEventArgs e)
{
    IEnumerable items = this.lsvStaffList.Items;
    foreach (Employee employee in items)
    {
        Console.WriteLine(employee.EmployeeId.ToString() 
            + "," + employee.EmployeeName.ToString() 
            + "," + employee.EmployeeDesignation.ToString());
    }
}

However, the EmployeeDesignation here is an int. If you want to get the actual EmployeeDesignation instance, you can manually "query" it like this:

private void btnProperty_Click(object sender, RoutedEventArgs e)
{
    IEnumerable items = this.lsvStaffList.Items;
    foreach (Employee employee in items)
    {
        Designation d = designations.First(p => p.Id == employee.EmployeeDesignation);

        Console.WriteLine(employee.EmployeeId.ToString() 
            + "," + employee.EmployeeName.ToString() 
            + "," + d.Name);
    }
}

UPDATE

As of 8/1/2014, the article I linked to above is still active, but the blog hasn't been updated in a while. That makes me worry that eventually it might disappear, and with it, the advocated solution. I'm reproducing the content of the article here for posterity. The words belong solely to the blog owner at Sanity Free Coding.

Today I wanted to refactor some code that prohibited my application from running multiple instances of itself.

Previously I had use System.Diagnostics.Process to search for an instance of my myapp.exe in the process list. While this works, it brings on a lot of overhead, and I wanted something cleaner.

Knowing that I could use a mutex for this (but never having done it before) I set out to cut down my code and simplify my life.

In the class of my application main I created a static named Mutex:

static class Program
{
    static Mutex mutex = new Mutex(true, "{8F6F0AC4-B9A1-45fd-A8CF-72F04E6BDE8F}");
    [STAThread]
    ...
}

Having a named mutex allows us to stack synchronization across multiple threads and processes which is just the magic I'm looking for.

Mutex.WaitOne has an overload that specifies an amount of time for us to wait. Since we're not actually wanting to synchronizing our code (more just check if it is currently in use) we use the overload with two parameters: Mutex.WaitOne(Timespan timeout, bool exitContext). Wait one returns true if it is able to enter, and false if it wasn't. In this case, we don't want to wait at all; If our mutex is being used, skip it, and move on, so we pass in TimeSpan.Zero (wait 0 milliseconds), and set the exitContext to true so we can exit the synchronization context before we try to aquire a lock on it. Using this, we wrap our Application.Run code inside something like this:

static class Program
{
    static Mutex mutex = new Mutex(true, "{8F6F0AC4-B9A1-45fd-A8CF-72F04E6BDE8F}");
    [STAThread]
    static void Main() {
        if(mutex.WaitOne(TimeSpan.Zero, true)) {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
            mutex.ReleaseMutex();
        } else {
            MessageBox.Show("only one instance at a time");
        }
    }
}

So, if our app is running, WaitOne will return false, and we'll get a message box.

Instead of showing a message box, I opted to utilize a little Win32 to notify my running instance that someone forgot that it was already running (by bringing itself to the top of all the other windows). To achieve this I used PostMessage to broadcast a custom message to every window (the custom message was registered with RegisterWindowMessage by my running application, which means only my application knows what it is) then my second instance exits. The running application instance would receive that notification and process it. In order to do that, I overrode WndProc in my main form and listened for my custom notification. When I received that notification I set the form's TopMost property to true to bring it up on top.

Here is what I ended up with:

Program.cs

static class Program
{
    static Mutex mutex = new Mutex(true, "{8F6F0AC4-B9A1-45fd-A8CF-72F04E6BDE8F}");
    [STAThread]
    static void Main() {
        if(mutex.WaitOne(TimeSpan.Zero, true)) {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
            mutex.ReleaseMutex();
        } else {
            // send our Win32 message to make the currently running instance
            // jump on top of all the other windows
            NativeMethods.PostMessage(
                (IntPtr)NativeMethods.HWND_BROADCAST,
                NativeMethods.WM_SHOWME,
                IntPtr.Zero,
                IntPtr.Zero);
        }
    }
}

NativeMethods.cs

// this class just wraps some Win32 stuff that we're going to use
internal class NativeMethods
{
    public const int HWND_BROADCAST = 0xffff;
    public static readonly int WM_SHOWME = RegisterWindowMessage("WM_SHOWME");
    [DllImport("user32")]
    public static extern bool PostMessage(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam);
    [DllImport("user32")]
    public static extern int RegisterWindowMessage(string message);
}

Form1.cs (front side partial)

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }
    protected override void WndProc(ref Message m)
    {
        if(m.Msg == NativeMethods.WM_SHOWME) {
            ShowMe();
        }
        base.WndProc(ref m);
    }
    private void ShowMe()
    {
        if(WindowState == FormWindowState.Minimized) {
            WindowState = FormWindowState.Normal;
        }
        // get our current "TopMost" value (ours will always be false though)
        bool top = TopMost;
        // make our form jump to the top of everything
        TopMost = true;
        // set it back to whatever it was
        TopMost = top;
    }
}

C# – Can’t create xmlns reference to other project in XAML

Check if

the fully qualified name for MyClass is MyApp.Domain.MyClass
MyClass has a default public constructor (with no parameters) so that XAML can instantiate it.

Best Answer

Related Solutions

C# – the correct way to create a single-instance WPF application

UPDATE

C# – Can’t create xmlns reference to other project in XAML

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