asp.net dynamically button with event handler
I have here a small problem with a dynamically generated buttons and their event handler in asp.net. I generate a flexible table with additional Buttons for special users. The buttons will generate dynamically, which works fine. But I can’t get the event handler to work.
Here are some pieces from my code: Build the button (In an own function).
…
Button ButtonChange = new Button();
ButtonChange.Text = "Change";
ButtonChange.ID = "change_" + i.ToString();
ButtonChange.Font.Size = FontUnit.Point(7);
ButtonChange.ControlStyle.CssClass = "button";
ButtonChange.Click += new EventHandler(test);
…
And
void test(object sender, EventArgs e)
{
// Do some stuff
}
My Page_Load
is empty.
But the program won’t jump to test, if I click the button. What’s going wrong?
Edit!!! The problem is that I don’t know at start how many rows I get from my sql query back. For every row I will add a delete and a change button. I call in my program a method which builds the result as a table. In this method, I check if the current user is an AdminUser and if he is, I will call buildAdminButtons function. Here, I create the buttons in a new column, for every row. How could I get this in OnLoad?
private void buildAdminButtons(TableRow tempRow, int i)
{
Button ButtonDelete = new Button();
Button ButtonChange = new Button();
TableCell change = new TableCell();
TableCell delete = new TableCell();
ButtonChange.Text = "Change";
ButtonChange.ID = "change_" + i.ToString();
ButtonChange.Font.Size = FontUnit.Point(7);
ButtonChange.ControlStyle.CssClass = "button";
ButtonDelete.Text = "Delete";
ButtonDelete.ID = "delete_" + i.ToString();
ButtonDelete.Font.Size = FontUnit.Point(7);
ButtonDelete.ControlStyle.CssClass = "button";
change.Controls.Add(ButtonChange);
delete.Controls.Add(ButtonDelete);
tempRow.Cells.Add(change);
tempRow.Cells.Add(delete);
}
I add to every button a unique id, which I don't know at the start. How could I handle this?
Solution 1:
You must have to place that code in page_load
or page_init
event.
protected void Page_Load()
{
Button ButtonChange = new Button();
ButtonChange.Text = "Change";
ButtonChange.ID = "change_" + i.ToString();
ButtonChange.Font.Size = FontUnit.Point(7);
ButtonChange.ControlStyle.CssClass = "button";
ButtonChange.Click += new EventHandler(test);
}
Read MSDN article - How to: Add Controls to an ASP.NET Web Page Programmatically?