从DataGrid WPF C＃中的选定行获取特定单元格的数据

Question

I have a DataGrid which I fill with data from my sql database. Now I want to get a specific cell (2nd cell) from the row I selected with a checkbox.

This is what I have now: WPF XAML:

<DataGrid Name="myGrid">
    <DataGrid.Columns>
        <DataGridTemplateColumn>
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <CheckBox Checked="CheckBox_Checked"/>
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
    <DataGridTextColumn Header="CustomerID" Width="Auto" Binding="{Binding CustomerID}"/>
    <DataGridTextColumn Header="ItemID" Width="Auto" Binding="{Binding ItemID}"/>
<DataGrid>

C# code:

private void CheckBox_Checked(object sender, RoutedEventArgs e)
    {
        DataGrid row = (DataGrid)myGrid.SelectedItems[1];
        System.Windows.MessageBox.Show(row);
    }

I get a error when running:

System.ArgumentOutOfRangeException

{"Index was out of range. Must be non-negative and less than the size of the collection.\\r\\nParameter name: index"}

What am I doing wrong? Do I have to use another approach to get the cell I want?

Answer 1

I finally found it! Very simple.

DataRowView drv = (DataRowView)myGrid.SelectedItem; 
String result = (drv["CustomerID"]).ToString(); 
MessageBox.Show(result);

Answer 2

MVVM Pattern.

Your XAML:

<DataGrid Name="myGrid" Grid.Row="1"  SelectionMode="Single" AutoGenerateColumns="False" CanUserAddRows="True" ItemsSource="{Binding YourCollection}" IsReadOnly="True" Background="#FFB8C1CB">
<DataGrid.Columns>

        <DataGridTextColumn Header="ID" Binding="{Binding yourColumnItem}" />

    </DataGrid.Columns>
</DataGrid>

ViewModel:

public ObservableCollection<YourType> YourCollection { get; private set; }
public DelegateCommand checkCommand { get; private set; }


public YourViewModel(){
    checkCommand = new checkCommand(param => checkExecuted(param));
}

private void CheckExecuted(Object param)
{
        YourType item = param as YourType;

        YourCollection = new ObservableCollection<YourType>();
        YourCollection = model.ReadInvoices();  //you'll need a model class
        DoStuff(item.yourColumnItem);  //get the cell you want
}

App.xaml.cs

private YourViewModel _ViewModel;

public App()
{
   _ViewModel = new YourViewModel();
}

protected override void OnStartup(StartupEventArgs e)
{
        base.OnStartup(e);

        _MainWindow = new MainWindow();
        _MainWindow.DataContext = _ViewModel;
        _MainWindow.Show();
        //delete the startupuri row from App.xaml

}

Your DelegateCommand class:

using System;
using System.Windows.Input;

namespace yourSolution.ViewModel
{

public class DelegateCommand : ICommand
{
    private readonly Action<Object> _Execute; 
    private readonly Func<Object, Boolean> _CanExecute; 


    public DelegateCommand(Action<Object> execute) : this(null, execute) { }


    public DelegateCommand(Func<Object, Boolean> canExecute, Action<Object> execute)
    {
        if (execute == null)
        {
            throw new ArgumentNullException("execute");
        }

        _Execute = execute;
        _CanExecute = canExecute;
    }


    public event EventHandler CanExecuteChanged;


    public Boolean CanExecute(Object parameter)
    {
        return _CanExecute == null ? true : _CanExecute(parameter);
    }


    public void Execute(Object parameter)
    {
        _Execute(parameter);
    }


    public void RaiseCanExecuteChanged()
    {
        if (CanExecuteChanged != null)
            CanExecuteChanged(this, EventArgs.Empty);
    }
}
}

DatabaseModel.cs:

public ObservableCollection<YourType> ReadInvoices()
{
        Connect();  //write connection
        YourCollection.Clear();  //this is a private data part
        MySqlCommand cmd = new MySqlCommand(write your query);
        MySqlDataReader dr = cmd.ExecuteReader();

        YourCollection.Clear();
        YourType item = new YourType();

        while (dr.Read()){
          item.column = dr.GetInt32("columnName"); //or any other type
          YourCollection.Add(item);
        }

        dr.Close();
        Disconnect();

return YourCollection;
}

Bind your command in the xaml to the selected item. This way it will become the parameter for CheckCommand:

Command="{Binding CheckCommand}" CommandParameter="{Binding ElementName=myGrid, Path=SelectedItem}"

I hope this covers everything. Of course you'll need EventHandlers to communicate with App.xaml.cs but I don't know what you want to do after processing your cell. I've only done this 3 times, I hope it works out.

Answer 3

Use this it 100% working.

object item = dataGrid1.SelectedItem;
           string ID = (dataGrid1.SelectedCells[0].Column.GetCellContent(item) as TextBlock).Text;

Answer 4

If I understand you correctly, you want to get the value from the selected row of the property that is data bound to the second column of your DataGrid . However, the code that you showed us does not do that:

private void CheckBox_Checked(object sender, RoutedEventArgs e)
{
    DataGrid row = (DataGrid)myGrid.SelectedItems[1]; // <--- 2nd item, not 2nd column!
    System.Windows.MessageBox.Show(row);
}

Your error was telling you...

Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index

... because you were trying to access the second item from the SelectedItems collection when there was only one (or no) item selected. Therefore, your used index ( 1 ) was out of range.

However, once you fixed that error, you would have immediately found another telling you that there is no default cast set up between a DataGrid (the type of your row parameter) and whatever type you have in the DataGrid , again due to this line:

DataGrid row = (DataGrid)myGrid.SelectedItems[1];

This should be...

YourDataType row = myGrid.SelectedItems[0];

... because the SelectedItems property returns the items from the collection that are selected. Once you have the data item from the selected row, then all you need to do is access the desired property from it... I believe that you were after the ItemID property value:

int ItemId = row.ItemID;

Answer 5

in wpf this one worked for me

<DataGrid Name="dataGridShowStudents">
</DataGrid>

private void dataGridShowStudents_MouseDoubleClick(object sender, MouseButtonEventArgs e){
        DataRowView drv = (DataRowView)dataGridShowStudents.SelectedItem;
        string result = drv[0].ToString();
        MessageBox.Show(result);
    }

Answer 6

YourDataGrid.SelectedIndex = X; 
DataRowView v = (DataRowView)YourDataGrid.SelectedItem;
TextBox1.Text = v[0].ToString();
TextBox2.Text = v[1].ToString();
TextBox3.Text = v[2].ToString();

If you want to use the cell value in a textbox, for example.