Question

I want to add image to GridView cell with below code but doesn’t show image

//aspx
 <asp:TemplateField HeaderText="image">
      <ItemTemplate>
          <asp:Image ID="img" runat="server" Width="100px" Height="100px" />
      </ItemTemplate>

//.cs -> In page_Load

for (int i = 0; i < GridView1.Rows.Count; i++)
{
      Image img = (Image)GridView1.Rows[i].FindControl("img");
      img.ImageUrl = path of image;
 }//for

Answer 1

You can use RowDataBound event to change something inside a GridView Row.

protected void GridView1_RowDatabound(object sender, GridViewRowEventArgs e)
{
    // check if this row is a row with Data (not Header or Footer)
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        // find your Image control in the Row
        Image image = ((Image)e.Row.FindControl("img"));
        // set the path of image
        img.ImageUrl = "path of image";     
    }
}

Or you can use a foreach statment to loop in Rows collection and change the path of image. this code could be on the Page_Load event.

foreach(GridViewRow row in GridView1.Rows)
{ 
    // check if this row is a row with Data (not Header or Footer)
    if (row.RowType == DataControlRowType.DataRow)
    {
        // find your Image control in the Row
        Image image = ((Image)row.FindControl("img"));
        // set the path of image
        img.ImageUrl = "path of image";     
    }
}

Edits

You cannot set the image out of the solution. Do to this, you have to create an Handler (.ashx file) and pass the name of your image on C: and return the a byte[], something like this:

public void ProcessRequest(HttpContext context)
{
    byte[] imageBytes = File.ReadAllBytes(@"C:\" + context.Request["image"]);
    context.Response.ContentType = "image/png";
    context.Response.BinaryWrite(imageBytes);
}

And on your page, set it by handler passing a image parameter in url:

Image image = ((Image)row.FindControl("img"));
img.ImageUrl = "ImageHandler.ashx?image=1.png";