I have an <asp:Calendar> in my code and I want to do is that when a date is clicked, it will show the selected date on the page.
protected void Calendar1_SelectionChanged(object sender, EventArgs e)
{
Label1.Text = "The selected date is " + Calendar1.SelectedDate.ToShortDateString();
}
I followed the code instructions from here, Microsoft's website.
But I get this error.
System.NullReferenceException: Object reference not set to an instance of an object.
I copied the same code as you pasted and its working for me. I am getting the date properly on Selection_Changed event. protected void Calendar1_SelectionChanged(object sender, EventArgs e) { string tst = Calendar1.SelectedDate.ToShortDateString(); }
the error you have mentioned can occur if your asp:Calendar control is in UpdatePanel.
The reason is you have your Label1 inside the ContentPlaceHolder. When your .aspx child page uses that placeholder, the label is removed from masterpage. So in the SelectionChanged event it doesn't find your Label1.
Move your Label outside of the mainContent ContentPlaceHolder