Error - already defines a member called 'InitializeComponent' with the same parameter types

Question

I tried to make an example of the book that shows exactly

private Button button1;
public MainWindow()
{
    InitializeComponent();
}
private void InitializeComponent()
{
    // Configure the form.
    this.Width = this.Height = 285;
    this.Left = this.Top = 100;
    this.Title = "Code-Only Window";
    // Create a container to hold a button.
    DockPanel panel = new DockPanel();
    // Create the button.
    button1 = new Button();
    button1.Content = "Please click me.";
    button1.Margin = new Thickness(30);
    // Attach the event handler.
    button1.Click += button1_Click;
    // Place the button in the panel.
    IAddChild container = panel;
    container.AddChild(button1);
    // Place the panel in the form.
    container = this;
    container.AddChild(panel);
}

private void button1_Click(object sender, RoutedEventArgs e)
{
    button1.Content = "Thank you.";
}

But it gives me an error:

"Type 'WpfApplication1.MainWindow' already defines a member called 'InitializeComponent' with the same parameter types"

Solution 1

WPF Window class created in Visual Studio usually has InitializeComponent method that is used to initialize its properties and contents - What does InitializeComponent() do, and how does it work in WPF?.

It is generated from your XAML markup and is not contained in your code-behind .cs file, but for the compiler(and msbuild.exe) it is still a valid intrinsic part of the Window class - if you create new empty Window and click on InitializeComponent() call then a *.g.i.cs temporary file with initialization code will be opened.

So, when you put another InitializeComponent method into the code behind file it causes ambiguous method definition.

---

SOLUTION:

Either rename your custom method to InitializeComponentsCustom and call it in the constructor:

public MainWindow()
{
    InitializeComponent();

    InitializeComponentsCustom();
}

private void InitializeComponentsCustom()
{
    // ...
}

or just put the entire code from book method into the constructor(just do not remove the original InitializeComponent call).

Solution 2

InitializeComponent method is generated automatically in MainWindow.g.cs when you define MainWindow.xaml.