How to populate textboxes using datagrid navigation

Question

Please I want to populate the textboxes and combo boxes in WPF with data from the datagrid as the user navigates from one row to the other in the datagrid. When the user click on a particular row, the record on the row populated the textboxes and combo boxes. How can I achieved this?

Answer

Hello @DPlug

Note that the following are not plug in code solution but instead paths to lead you to what you want.

Following along with the following Microsoft code sample. Then for a start see the following TechNet article and code which does not have a ComboBox nor DataGrid but instead a ListBox, don't get hung up on the ListBox.

The screenshot below is for the TechNet article, ignore VB.NET as the actual code has one project for C#, one for VB.NET

DataGrid

MainWindow Modified source

protected override async void OnContentRendered(EventArgs e)  
{  
    base.OnContentRendered(e);  
  
    if (_hasShown)  
    {  
        return;  
    }  
  
    _hasShown = true;  
  
    var employeeCollection = new ObservableCollection();  
  
    //await Task.Run(async () =>  
    //{  
    //    employeeCollection = new ObservableCollection(await _context.Employees.ToListAsync());  
    //});  
  
    await Task.Delay(1);  
    employeeCollection = new ObservableCollection(EmployeesOperations.List());  
  
  
    EmployeeGrid.ItemsSource = employeeCollection;  
    employeeCollection.CollectionChanged += EmployeeCollection_CollectionChanged;  
    DataContext = employeeCollection;  
  
    /*  
     * Find employee by last name, if found  
     * select and scroll into view in the DataGrid  
     */  
    var employee = (employeeCollection)  
        .FirstOrDefault(emp => emp.LastName == "Russell");  
  
    if (employee == null) return;  
  
    EmployeeGrid.SelectedItem = employee;  
    EmployeeGrid.ScrollIntoView(employee);  
  
    SaveButton.IsEnabled = true;  
  
}

Data reader

Code added, used above. Note extension class DbExtensions should be in it's own file

using System;  
using System.Collections.Generic;  
using System.Data;  
using System.Globalization;  
using System.Linq;  
using System.Text;  
using System.Threading.Tasks;  
using Microsoft.Data.SqlClient;  
using WpfApp1.Models;  
  
namespace WpfApp1.Classes  
{  
    public class EmployeesOperations  
    {  
        public static string ConnectionString =  
            "Data Source=.\SQLEXPRESS;database=HumanResources;Integrated Security=True";  
  
        public static List List()  
        {  
            var list = new List() ;  
              
            var selectStatement =  
                @"  
            SELECT   
                employee_id, first_name, last_name, email, phone_number, hire_date, job_id, salary, manager_id, department_id   
            FROM   
                dbo.employees;  
";  
  
            using (var cn = new SqlConnection() { ConnectionString = ConnectionString })  
            {  
                using (var cmd = new SqlCommand() { Connection = cn, CommandText = selectStatement})  
                {  
                    cn.Open();  
                    var reader = cmd.ExecuteReader();  
                    while (reader.Read())  
                    {  
                         
                        var employee = new Employees()  
                        {  
                            EmployeeId = reader.GetInt32(0),  
                            FirstName = reader.GetString(1),  
                            LastName = reader.GetString(2),  
                            Email = reader.GetString(3),  
                            PhoneNumber = reader.SafeGetString(4),  
                            HireDate = reader.GetDateTime(5),  
                            JobId = reader.GetInt32(6),  
                            Salary = reader.GetDecimal(7),  
                            ManagerId = reader["manager_id"].DbCast(),  
                            DepartmentId = reader.GetInt32(9),  
                            Manager = new Employees(),   
                            InverseManager = new List()  
                        };  
  
                        list.Add(employee);  
                    }  
                }  
            }  
  
            return list;  
        }  
    }  
  
    public static class DbExtensions  
    {  
        public static T? DbCast(this object dbValue) where T : struct  
        {  
            switch (dbValue)  
            {  
                case null:  
                case DBNull _:  
                    return null;  
            }  
  
            T? value = dbValue as T?;  
            if (value != null)  
            {  
                return value;  
            }  
  
            if (dbValue is IConvertible conv)  
            {  
                value = (T)conv.ToType(typeof(T), CultureInfo.InvariantCulture);  
            }  
              
            return value;  
        }  
        public static string SafeGetString(this SqlDataReader reader, int colIndex)  
        {  
            if (!reader.IsDBNull(colIndex))  
            {  
                return reader.GetString(colIndex);  
            }  
  
            return string.Empty;  
        }  
    }  
}

Answer

I will give you a demo with MVVM to implement what you want.

Part 1: Code for MainWindow.xaml

Part 2: Code for MainWindow.xaml.cs

  public enum SexOpt { Male, Female };  
  
    public class PersonModel : NotifyObject  
    {        
        private string name;  
        public string Name  
        {  
            get { return name; }  
            set  
            {  
                name = value;  
                OnPropertyChange("Name");  
            }  
        }  
        private int age;  
        public int Age  
        {  
            get { return age; }  
            set  
            {  
                age = value;  
                OnPropertyChange("Age");  
            }  
        }  
  
        private SexOpt sex;  
        public SexOpt Sex   
        {  
            get { return sex; }  
            set {  
                sex = value;  
                OnPropertyChange("Sex");  
            }  
        }  
    }  
  
  
    class PersonViewModel: NotifyObject  
    {  
        private PersonModel user;  
        public PersonModel User  
        {  
            get { return user; }  
            set  
            {  
                user = value;  
                OnPropertyChange("User");  
            }  
        }  
  
        private ObservableCollection ltPersons = new ObservableCollection();  
        public ObservableCollection LtPersons  
        {  
            get { return ltPersons; }  
            set  
            {  
                this.ltPersons = value;  
                OnPropertyChange("LtPersons");  
            }  
        }  
  
        public PersonViewModel()  
        {  
            LtPersons = new ObservableCollection()   
            {   
                new PersonModel { Name = "John", Age = 11 , Sex = SexOpt.Male},   
                new PersonModel { Name = "Juli", Age = 12 ,Sex = SexOpt.Female},   
                new PersonModel { Name = "Brace", Age = 13 ,Sex = SexOpt.Male}   
            };  
        }  
    }  
  
  
    public class NotifyObject : INotifyPropertyChanged  
    {  
        public event PropertyChangedEventHandler PropertyChanged;  
        protected void OnPropertyChange(string propertyName)  
        {  
            if (PropertyChanged != null)  
            {  
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));  
            }  
        }  
    }

The picture for result:

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Answer

Hi,
try following demo. Al left window side you see the DataGrid with rows for each data object. At rigth side you see the selected row (data object) for editing.

XAML:

And classes:

using System;  
using System.Collections.ObjectModel;  
using System.ComponentModel;  
using System.Runtime.CompilerServices;  
using System.Windows.Data;  
  
namespace WpfApp1  
{  
  class ViewModel : INotifyPropertyChanged  
  {  
    // ctor to fill demo data  
    public ViewModel()  
    {  
      Random rnd = new Random();  
  
      // Lookup data (display list in ComboBox)  
      ObservableCollection colLookUp = new ObservableCollection();  
      for (int i = 1; i < 10; i++) colLookUp.Add(new LookUpData { ID = i, Text = $"Lookup-Text {i}" });  
      cvsLookUp.Source = colLookUp;  
  
      // data objects (DataGrid rows)  
      ObservableCollection colData = new ObservableCollection();  
      for (int i = 1; i < 50; i++) colData.Add(new Data { ID = i, Info = $"Row {i}", FK = rnd.Next(1,colLookUp.Count+1) });  
      cvsData.Source = colData;  
  
      cvsData.View.CurrentChanged += (sender, e) => { SelectedObject = cvsData.View.CurrentItem; };  
      cvsData.View.MoveCurrentToPosition(-1);  
      cvsData.View.MoveCurrentToFirst();  
    }  
  
    // DataGrid view  
    private CollectionViewSource cvsData = new CollectionViewSource();  
    public ICollectionView ViewData { get { return cvsData.View; } }  
  
    // ComboBox view  
    private CollectionViewSource cvsLookUp = new CollectionViewSource();  
    public ICollectionView ViewLookUp { get { return cvsLookUp.View; } }  
  
    // for Detail display and edit  
    private object _selectedObject = null;  
    public object SelectedObject  
    {  
      get => this._selectedObject;  
      set { this._selectedObject = value; OnPropertyChanged(); }  
    }  

 public event PropertyChangedEventHandler PropertyChanged;  
    private void OnPropertyChanged([CallerMemberName] string propName = "") => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propName));  
  
  }  
  
  // DataGrid data  
  public class Data  
  {  
    public int ID { get; set; }  
    public string Info { get; set; }  
    public int FK { get; set; } // foreign key value  
  }  
  
  // ComboBox list data (lookup data)  
  public class LookUpData  
  {  
    public int ID { get; set; } // Key value  
    public string Text { get; set; } // text to display in DataGrid (ComboBoxColumn)  
  }  
}

Result:

Answer

Hi,
if you want to use ADO.NET to read data from SQL Server you can use this classes instead of my other code.

Classes:

using System;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Runtime.CompilerServices;
using System.Windows.Data;

namespace WpfApp1
{
  class ViewModel : INotifyPropertyChanged
  {
    // ctor to load demo data
    public ViewModel()
    {
      Model mod = new Model();

      // Lookup data (display list in ComboBox)
      cvsLookUp.Source = mod.GetLookUp();

      // data objects (DataGrid rows)
      cvsData.Source = mod.GetData();

      cvsData.View.CurrentChanged += (sender, e) => { SelectedObject = cvsData.View.CurrentItem; };
      cvsData.View.MoveCurrentToPosition(-1);
      cvsData.View.MoveCurrentToFirst();
    }

    // DataGrid view
    private CollectionViewSource cvsData = new CollectionViewSource();
    public ICollectionView ViewData { get { return cvsData.View; } }

    // ComboBox view
    private CollectionViewSource cvsLookUp = new CollectionViewSource();
    public ICollectionView ViewLookUp { get { return cvsLookUp.View; } }

    // for Detail display and edit
    private object _selectedObject = null;
    public object SelectedObject
    {
      get => this._selectedObject;
      set { this._selectedObject = value; OnPropertyChanged(); }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    private void OnPropertyChanged([CallerMemberName] string propName = "") => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propName));

  }

  internal class Model
  {
    internal DataTable GetLookUp()
    {
      DataTable dt = new DataTable();
      using (SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM [Table2]", WpfApp1.Properties.Settings.Default.cnSQL))
        da.Fill(dt);
      return dt;
    }
    internal DataTable GetData()
    {
      DataTable dt = new DataTable();
      using (SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM [Table1]", WpfApp1.Properties.Settings.Default.cnSQL))
        da.Fill(dt);
      return dt;
    }
  }
}

To create SQL server tables and fill with demo data you can use following method:

internal void CraeteData()
{
  using (SqlConnection cn = new SqlConnection(WpfApp1.Properties.Settings.Default.cnSQL))
  {
    cn.Open();
    using (SqlCommand cmd = new SqlCommand { Connection = cn })
    {
      // delete previous table in SQL Server 2016 and above
      cmd.CommandText = "DROP TABLE IF EXISTS Table1;DROP TABLE IF EXISTS Table2;";
      cmd.ExecuteNonQuery();
      // Create Table
      cmd.CommandText = "CREATE Table [Table1]([ID] int Identity, [Info] nvarchar(50), [FK] int, CONSTRAINT [PK_Table1] PRIMARY KEY ([ID]))";
      cmd.ExecuteNonQuery();
      cmd.CommandText = "CREATE Table [Table2]([ID] int Identity, [Text] nvarchar(50), CONSTRAINT [PK_Table2] PRIMARY KEY ([ID]))";
      cmd.ExecuteNonQuery();

      // data objects (DataGrid rows)
      Random rnd = new Random();
      cmd.CommandText = "INSERT [Table1](Info, FK) VALUES (@info, @fk);";
      cmd.Parameters.Add("@info", SqlDbType.NVarChar, 50);
      cmd.Parameters.Add("@fk", SqlDbType.Int);
      for (int i = 1; i < 50; i++)
      {
        cmd.Parameters["@info"].Value = $"Row {i}";
        cmd.Parameters["@fk"].Value = rnd.Next(1, 10);
        cmd.ExecuteNonQuery();
      }

      // Lookup data (display list in ComboBox)  
      cmd.CommandText = "INSERT [Table2](Text) VALUES (@text);";
      cmd.Parameters.Clear();
      cmd.Parameters.Add("@text", SqlDbType.NVarChar, 50);
      for (int i = 1; i < 10; i++)
      {
        cmd.Parameters["@text"].Value = $"Lookup-Text {i}";
        cmd.ExecuteNonQuery();
      }
    }
  }
}

How to populate textboxes using datagrid navigation

4 answers

DataGrid

MainWindow Modified source

Data reader