滚动后，Datagrid正在选择错误的行

Question

I have a datagrid within a WinForm application that is bound to a list of Addresses. The list of addresses is long, so I have to scroll to select the address I want. However, after I scroll and find the address I want and select it, the datagrid will select the address that was in the same position on the grid when the form was first loaded. I was wondering what I am doing wrong and how to might I get my desired result.

    // 
// bindingSource1
// 
   private System.Windows.Forms.BindingSource bindingSource1;
   this.bindingSource1 = new System.Windows.Forms.BindingSource(this.components);
this.bindingSource1.DataSource = typeof(ViewModels.ListAddressViewModel);

            // 
        // dataGridView1
        // 
        this.dataGridView1.AllowUserToAddRows = false;
        this.dataGridView1.AllowUserToDeleteRows = false;
        this.dataGridView1.AllowUserToOrderColumns = true;
        this.dataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
        this.dataGridView1.Columns.AddRange(new System.Windows.Forms.DataGridViewColumn[] {
        this.HouseNumber,
        this.Prefix,
        this.StreetName,
        this.StreetType,
        this.StreetSuffix,
        this.SecondaryType,
        this.SecondaryNumber,
        this.City,
        this.State,
        this.ZipCode});
        this.dataGridView1.DataBindings.Add(new System.Windows.Forms.Binding("DataSource", this.bindingSource1, "AddressList", true, System.Windows.Forms.DataSourceUpdateMode.OnPropertyChanged));
        this.dataGridView1.Dock = System.Windows.Forms.DockStyle.Fill;
        this.dataGridView1.Location = new System.Drawing.Point(0, 50);
        this.dataGridView1.MultiSelect = false;
        this.dataGridView1.Name = "dataGridView1";
        this.dataGridView1.ReadOnly = true;
        this.dataGridView1.RowHeadersVisible = false;
        this.dataGridView1.SelectionMode = System.Windows.Forms.DataGridViewSelectionMode.FullRowSelect;
        this.dataGridView1.ShowCellErrors = false;
        this.dataGridView1.ShowCellToolTips = false;
        this.dataGridView1.ShowEditingIcon = false;
        this.dataGridView1.ShowRowErrors = false;
        this.dataGridView1.Size = new System.Drawing.Size(1014, 421);
        this.dataGridView1.TabIndex = 2;
        this.dataGridView1.SelectionChanged += new System.EventHandler(this.dataGridView1_SelectionChanged);

                //Selection Change Handler
    private void dataGridView1_SelectionChanged(object sender, EventArgs e)
    {
        if (dataGridView1.SelectedRows.Count > 0)
        {
            _vm.SelectedAddress = (Address)dataGridView1.SelectedRows[0].DataBoundItem;
        }
    }


//My View Model (_vm) 
public class ListAddressViewModel
{
      public IList<Address> AddressList { get; set; }
      private IAddressRepository _repo;
      public Address SelectedAddress {get;set;}

      public ListAddressViewModel()
      {
         AddressList = new List<Address>();
      }

      public ListAddressViewModel(IAddressRepository AddrRepo)
          :this()
      { 
          _repo = AddrRepo
          init();
      }

      private void init()
      {
         if(_repo != null)
         { 
            AddressList = _repo.FindAll();
         }
      }

      ... etc..
}

Answer 1

something like this ...

     if (dataGridView1.SelectedRows.Count > 0)
    {
    _vm.SelectedAddress =(Address)dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells["Address"].Value.ToString();
    }

Answer 2

Probably not a very helpful answer, but I couldn't replicate your issue. I've posted the code that I used and I got the correct selection each time. The only change I made was to change the datagridview1.DataSource to be an instance of ListAddressViewModel instead of the type - which probably doesn't solve the problem in itself as it was just a way for me to feed data in. Anyway, here's my code for what it's worth! Hopefully it will help someone else. Note I have commented out original code where I have made amendments in the Form code.

public class Address
{
    public string AddressLine1 { get; set; }
    public string City { get; set; }
    public string PostCode { get; set; }
}

public class ListAddressViewModel
{
    public IList<Address> AddressList { get; set; }
    public Address SelectedAddress { get; set; }

    public ListAddressViewModel()
    {
        AddressList = new List<Address>();
        init();
    }


    private void init()
    {
        AddressList = new List<Address>
        {
            new Address { AddressLine1 = "Address 1", City = "City 1", PostCode = "PostCode 1" },
            new Address { AddressLine1 = "Address 2", City = "City 2", PostCode = "PostCode 2" },
            new Address { AddressLine1 = "Address 3", City = "City 3", PostCode = "PostCode 3" },
            new Address { AddressLine1 = "Address 4", City = "City 4", PostCode = "PostCode 4" },
            new Address { AddressLine1 = "Address 5", City = "City 5", PostCode = "PostCode 5" },
            new Address { AddressLine1 = "Address 6", City = "City 6", PostCode = "PostCode 6" },
            new Address { AddressLine1 = "Address 7", City = "City 7", PostCode = "PostCode 7" },
            new Address { AddressLine1 = "Address 8", City = "City 8", PostCode = "PostCode 8" },
            new Address { AddressLine1 = "Address 9", City = "City 9", PostCode = "PostCode 9" },
            new Address { AddressLine1 = "Address 10", City = "City 10", PostCode = "PostCode 10" },
            new Address { AddressLine1 = "Address 11", City = "City 11", PostCode = "PostCode 11" },
            new Address { AddressLine1 = "Address 12", City = "City 12", PostCode = "PostCode 12" },
            new Address { AddressLine1 = "Address 13", City = "City 13", PostCode = "PostCode 13" },
            new Address { AddressLine1 = "Address 14", City = "City 14", PostCode = "PostCode 14" },
            new Address { AddressLine1 = "Address 15", City = "City 15", PostCode = "PostCode 15" },
            new Address { AddressLine1 = "Address 16", City = "City 16", PostCode = "PostCode 16" },
            new Address { AddressLine1 = "Address 17", City = "City 17", PostCode = "PostCode 17" },
            new Address { AddressLine1 = "Address 18", City = "City 18", PostCode = "PostCode 18" },
            new Address { AddressLine1 = "Address 19", City = "City 19", PostCode = "PostCode 19" }
        };
    }

}

public partial class Form3 : Form
{
    private System.Windows.Forms.BindingSource bindingSource1;
    private ListAddressViewModel VM { get; set; }
    private DataGridView dataGridView1;

    public Form3()
    {
        InitializeComponent();

        this.dataGridView1 = new DataGridView();
        this.VM = new ListAddressViewModel();
        this.bindingSource1 = new System.Windows.Forms.BindingSource(this.components);
        //this.bindingSource1.DataSource = typeof(ListAddressViewModel);
        this.bindingSource1.DataSource = this.VM;

        this.dataGridView1.AllowUserToAddRows = false;
        this.dataGridView1.AllowUserToDeleteRows = false;
        this.dataGridView1.AllowUserToOrderColumns = true;
        this.dataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
        //this.dataGridView1.Columns.AddRange(new System.Windows.Forms.DataGridViewColumn[] {
        //    this.AddressLine1,
        //    this.City,
        //    this.PostCode});
        this.dataGridView1.DataBindings.Add(new System.Windows.Forms.Binding("DataSource", this.bindingSource1, "AddressList", true, System.Windows.Forms.DataSourceUpdateMode.OnPropertyChanged));
        //this.dataGridView1.Dock = System.Windows.Forms.DockStyle.Fill;
        //this.dataGridView1.Location = new System.Drawing.Point(0, 50);
        this.dataGridView1.Location = new System.Drawing.Point(33, 27);
        this.dataGridView1.MultiSelect = false;
        this.dataGridView1.Name = "dataGridView1";
        this.dataGridView1.ReadOnly = true;
        this.dataGridView1.RowHeadersVisible = false;
        this.dataGridView1.SelectionMode = System.Windows.Forms.DataGridViewSelectionMode.FullRowSelect;
        this.dataGridView1.ShowCellErrors = false;
        this.dataGridView1.ShowCellToolTips = false;
        this.dataGridView1.ShowEditingIcon = false;
        this.dataGridView1.ShowRowErrors = false;
        //this.dataGridView1.Size = new System.Drawing.Size(1014, 421);
        this.dataGridView1.Size = new System.Drawing.Size(345, 150);
        this.dataGridView1.TabIndex = 2;
        this.dataGridView1.SelectionChanged += new System.EventHandler(this.dataGridView1_SelectionChanged);
        this.Controls.Add(this.dataGridView1);
    }



    //Selection Change Handler
    private void dataGridView1_SelectionChanged(object sender, EventArgs e)
    {
        if (dataGridView1.SelectedRows.Count > 0)
        {
            var addr = (Address)dataGridView1.SelectedRows[0].DataBoundItem;
            var msg = String.Format("{0}, {1}, {2}", addr.AddressLine1, addr.City, addr.PostCode);
            MessageBox.Show(msg, "Message", MessageBoxButtons.OK);
        //    _vm.SelectedAddress = (Address)dataGridView1.SelectedRows[0].DataBoundItem;
        }
    }
}

Answer 3

String AddressLine1 = dataGridView1.SelectedRows[0].Cells[Columnindex].Value.ToString()

String City = dataGridView1.SelectedRows[0].Cells[Columnindex].Value.ToString()

String PostCode = dataGridView1.SelectedRows[0].Cells[Columnindex].Value.ToString()

Answer 4

Try using the selected index of the row and not the selected rows collection. I had an issue with this using Telerik's gridview because of the grid's virtualization.

There are so many ways to use the index of the current row being selected but here is another way as well.

 private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
    {
       //e holds column and row index's selected
    }

I cant say much more because I don't know the whole scope of your code.