如何在C＃的datagridview中将文本添加到行标题中？

Question

There are many questions concerning this issue here, but I have tried the solutions posted and still don't get it to work.

I have a datagridview where I want to show the rownumber on the row headers. This is what I have tried:

 gridView.RowHeadersWidthSizeMode = System.Windows.Forms.DataGridViewRowHeadersWidthSizeMode.AutoSizeToDisplayedHeaders;           
            gridView.AutoResizeRowHeadersWidth(
                DataGridViewRowHeadersWidthSizeMode.AutoSizeToAllHeaders);


            foreach (DataGridViewRow row in gridView.Rows)
            {
                row.HeaderCell.Value = (row.Index + 1).ToString();
            }

This code is called from the OnLoad event, since in other questions it is stated that the code should not be run in the constructor.

Advice? Thanks!

Answer 1

I think my approach would be to bind a row on the ItemDataBound event rather than going over the rows all a single place. Something along the lines of:

    /// <summary>
    /// Which row is currently being rendered
    /// </summary>
    protected int RowIndex { get; set; }

    protected override void OnLoad(EventArgs e)
    {      
      this.RowIndex = 0;
      this.DataGrid.DataSource = new string[] { "a", "b", "c" }; // bind the contents
      this.DataGrid.DataBind();      
    }

    /// <summary>
    /// When an item is bound
    /// </summary>
    protected void OnItemDataBound(object sender, DataGridItemEventArgs e)
    {
      this.RowIndex++;
      Label label = e.Item.FindControl("RowLabel") as Label;
      if (label != null)
      {
        label.Text = this.RowIndex.ToString();
      }
    }

Answer 2

using a grid view you can detect in the OnRowDataBound event if this is the Header row like so:

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            if (e.Row.RowType == DataControlRowType.Header)
            {
                Label label = e.Row.FindControl("RowLabel") as Label;
               label.Text = "the text i want";
            }
        }

This event fires when the grid databinds. It will fire for every row of data that is bound as well as the header and footer rows.

SO you will call DataGridView1.Databind() during the Page_Load event most probably and this will trigger the OnRowDataBound event multiple times.