LINQPad.Controls Event sender got null

rovingwind · January 2025

// Winform
var button = new System.Windows.Forms.Button {
  Text = "Copy",
  Location = new Point(150, 100),
  Size = new Size(100, 30)
};

button.Click += (sender, e) => {
  //here can got button object
  var buttonSender = (sender as System.Windows.Forms.Button);    
};

// LINQPad.Controls
var button = new LINQPad.Controls.Button("Copy").Dump();
button.Click += (sender, e) => {
  // this got null
  var buttonSender = (sender as LINQPad.Controls.Button);    
};

Why transform sender to LINQPad.Controls always got null

i2van · January 2025

var button = new LINQPad.Controls.Button("Copy").Dump();
button.Click += (sender, e) => {
  var buttonSender = sender.GetType().Dump();
};

LINQPad.Controls.Core.HtmlElement

JoeAlbahari · January 2025

Good spot. This is not ideal behavior - LINQPad should supply the button as the sender, not the HtmlElement. Fixing it is a breaking change, though, so it might have to wait for LINQPad 9.

rovingwind · October 2

@JoeAlbahari said:
Good spot. This is not ideal behavior - LINQPad should supply the button as the sender, not the HtmlElement. Fixing it is a breaking change, though, so it might have to wait for LINQPad 9.

Is this issue fixed in LINQPad 9?

JoeAlbahari · October 2

It didn't pass review because that change that would still break existing scripts.

Is there any reason that you need this? The sender parameter was useful in the C# 1 days, before the language had closures. But now we can do this (which is also type-safe):

var button = new LINQPad.Controls.Button("Copy").Dump();
button.Click += (sender, e) => {
  var buttonSender = button;
};

LINQPad.Controls Event sender got null

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