[RESOLVED] Initializing Custom Control at runtime

[cfirex]

Hi,

I've a user control in a window form application and I want initialize it, at runtime, with a custom method in the Form1 class.

public partial class Form1 : System.Windows.Forms.Form
{
private UC1 myUserControl;
...

In the Form1.cs InitializeComponent method I've :

this.UC1 = initComponent();

This is a method of the Form1 class, that return a myUserControl object.

I can compile but if I switch to the designer I get this error :

Impossible to find the method 'System.Windows.Forms.Form.initComponent'

Why this ?

[Atheist]

Where and how have you declared initComponent method?

[jmcilhinney]

Do not, under any circumstances, edit the code in the InitializeComponent method. That code is generated by the IDE and if you do the wrong thing there you could render your form unusable. What's more, as soon as you make a change in the designer all that code will be regenerated and your code will be lost. You should be adding code either to the form's constructor, AFTER the call to InitializeComponent, or else in the Load event handler.

[RobDog888]

When you drop a user created control on to a form it should automatically get included in the forms initialization code. You shouldnt have to edit it at all.

[cfirex]

For example, this is Form1.Designer.cs

namespace WindowsApplication1
{
    partial class Form1
    {
        private System.ComponentModel.IContainer components = null;

        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form

        private void InitializeComponent()
        {
            this.SuspendLayout();

            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(292, 266);
            this.Name = "Form1";
            this.Text = "Form1";
            this.ResumeLayout(false);

            // this line GENERATED AN ERROR if I try to open the designer :
            this.myUserControl  = myNewUserControl();
        }

        #endregion
    }
}

and Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace WindowsApplication1
{
    public partial class Form1 : System.Windows.Forms.Form
    {
        private UserControl1 myUserControl;

        public Form1()
        {
            InitializeComponent();
        }

        private UserControl1 myNewUserControl()
        {
            // example empty initialization method !!!
            UserControl1 myUC = new UserControl1();
            return myUC;
        }

    }
}

This is a very simple example code, the UserControl1 is a simple label + textbox user control.

[jmcilhinney]

A UserControl is just like any other control. You're supposed to add them to the form in the designer, just like any other control. If you do need to create one at run time then you do it like this:

MyUserControl uc = new MyUserControl();
 
// Set properties here.
 
this.Controls.Add(uc);

just like any other control. As I have already said, do NOT add your own code to the InitializeComponent method. As I have already said, do NOT add your own code to the InitializeComponent method. As I have already said twice, do NOT add your own code to the InitializeComponent method.