C# InitializeComponent Method

InitializeComponent. In Windows Forms we create programs visually.

We drag controls to the Form in Visual Studio. Behind the scenes, Visual Studio adds code to the InitializeComponent method, which is called in the Form constructor.

Form

Example. In this code sample, we see the InitializeComponent method when a new program is created. Then, we see InitializeComponent after adding a Button control by dragging one to the Window in the Designer.

Also: We see that statements for button1 were added to the contents. Visual Studio added the SuspendLayout and ResumeLayout method calls.

Initial contents of InitializeComponent: C#

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
    this.components = new System.ComponentModel.Container();
    this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
    this.Text = "Form1";
}

Contents after adding Button: C#

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
    this.button1 = new System.Windows.Forms.Button();
    this.SuspendLayout();
    //
    // button1
    //
    this.button1.Location = new System.Drawing.Point(13, 13);
    this.button1.Name = "button1";
    this.button1.Size = new System.Drawing.Size(75, 23);
    this.button1.TabIndex = 0;
    this.button1.Text = "button1";
    this.button1.UseVisualStyleBackColor = true;
    //
    // Form1
    //
    this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
    this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
    this.ClientSize = new System.Drawing.Size(292, 273);
    this.Controls.Add(this.button1);
    this.Name = "Form1";
    this.Text = "Form1";
    this.ResumeLayout(false);
}

Do not modify. It is best not to modify the InitializeComponent method, but in some cases it may be useful to. Sometimes, when creating a program you may remove a Control and the InitializeComponent method will no longer compile.

And: In this case, you can find the compilation error and fix it, usually by removing lines.

Compile-Time Error

Discussion. When you create a new program, the InitializeComponent() call is located in the Form1 constructor body. Should you add code before or after this call? If the code doesn't interact with the controls, either location is fine.

However: If the code does interact with the controls, you will want to put the code after the InitializeComponent call.

Also, you can create a Form1_Load event handler. You can do this by double-clicking on the Form in the Designer. This will run after the Form1 constructor. This is a good way to separate your code from the InitializeComponent call.

Summary. We looked at the InitializeComponent method in the C# language and Windows Forms platform. The InitializeComponent method call is implemented with a partial class to make your part of the code easier to edit.

Partial Class

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