Message transmission between user controls and forms in C #

If the events in the User-Defined control are hooked to the called Form Events in C #,

We all know that in Asp.net development, user-defined controls can effectively modularize programs. It can also be used in. Net winform.

Details: 1. Create an application windowsapplication1. 2. Add a new user control userlogin. (User) 3. Define User attributes

// Define attributes
Public String Username
{
Get {return username ;}
Set {username = value ;}
}
Public String Password
{
Get {return password ;}
Set {Password = value ;}
}

4. Define Delegation

// Define the delegate
Public Delegate void btnokclickeventhander (Object sender, eventargs E );
Public Delegate void btncancelclickeventhander (Object sender, eventargs E );

5. Define events

// Define the event
Public event btnokclickeventhander btnokclick;
Public event btncancelclickeventhander btncancelclick

6. Event implementation

Private void textboxuid_textchanged (Object sender, system. eventargs E)
{
Username = This. textboxuid. text;
} Private void textboxpwd_textchanged (Object sender, system. eventargs E)
{
Password = This. textboxpwd. text;
} Private void buttonok_click (Object sender, system. eventargs E)
{
If (btnokclick! = NULL)
Btnokclick (this, e );
} Private void buttoncancel_click (Object sender, system. eventargs E)
{
If (btncancelclick! = NULL)
Btncancelclick (this, e );
}

7. Call user control events and receive messages in form1 winform.

Protected void okclick (Object send, system. eventargs E)
{
MessageBox. Show ("uid:" + userlogin1.username + "; PWD:" + userlogin1.password, "usermessage ");
} Protected void cancelclick (Object send, system. eventargs E)
{
This. Close ();
}

8. Press F5 to run (result) with 1 (windowsapplication1 source code)

Using system;
Using system. drawing;
Using system. collections;
Using system. componentmodel;
Using system. Windows. forms;
Using system. Data; namespace windowsapplication1
{
/// <Summary>
/// Summary of form1.
/// </Summary>
Public class form1: system. Windows. Forms. Form
{
Private system. Windows. Forms. Panel Panel1;
Private windowsapplication1.userlogin userlogin1;
/// <Summary>
/// Required designer variables.
/// </Summary>
Private system. componentmodel. Container components = NULL; Public form1 ()
{
//
// Required for Windows Form Designer support
//
Initializecomponent ();
Userlogin1.btnokclick + = new btnokclickeventhander (okclick );
Userlogin1.btncancelclick + = new btncancelclickeventhander (cancelclick );
//
// Todo: add Any constructor code after initializecomponent calls
//
} // <Summary>
/// Clear all resources in use.
/// </Summary>
Protected override void dispose (bool disposing)
{
If (disposing)
{
If (components! = NULL)
{
Components. Dispose ();
}
}
Base. Dispose (disposing );
} # Code generated by region windows Form Designer
/// <Summary>
/// The designer supports the required methods-do not use the code editor to modify
/// Content of this method.
/// </Summary>
Private void initializecomponent ()
{
This. Panel1 = new system. Windows. Forms. Panel ();
This. userlogin1 = new windowsapplication1.userlogin ();
This. panel1.suspendlayout ();
This. suspendlayout ();
//
// Panel1
//
This. panel1.controls. Add (this. userlogin1 );
This.panel1.doc K = system.windows.forms.doc kstyle. Fill;
This. panel1.location = new system. Drawing. Point (0, 0 );
This. panel1.name = "Panel1 ";
This. panel1.size = new system. Drawing. Size (216,101 );
This. panel1.tabindex = 1;
//
// Userlogin1
//
This.userlogin1.doc K = system.windows.forms.doc kstyle. Fill;
This. userlogin1.location = new system. Drawing. Point (0, 0 );
This. userlogin1.name = "userlogin1 ";
This. userlogin1.size = new system. Drawing. Size (216,101 );
This. userlogin1.tabindex = 0;
//
// Form1
//
This. autoscalebasesize = new system. Drawing. Size (6, 14 );
This. clientsize = new system. Drawing. Size (216,101 );
This. Controls. Add (this. Panel1 );
This. Name = "form1 ";
This. Text = "form1 ";
This. panel1.resumelayout (false );
This. resumelayout (false );}
# Endregion // <summary>
/// Main entry point of the application.
/// </Summary>
[Stathread]
Static void main ()
{
Application. Run (New form1 ());
}
Protected void okclick (Object send, system. eventargs E)
{
MessageBox. Show ("uid:" + userlogin1.username + "; PWD:" + userlogin1.password, "usermessage ");
} Protected void cancelclick (Object send, system. eventargs E)
{
This. Close ();
}}
}

Appendix 2 (userlogin source code)

Using system;
Using system. collections;
Using system. componentmodel;
Using system. drawing;
Using system. Data;
Using system. Windows. forms; namespace windowsapplication1
{
/// <Summary>
/// Summary of usercontrol1.
/// </Summary>
//// Define the delegate
Public Delegate void btnokclickeventhander (Object sender, eventargs E );
Public Delegate void btncancelclickeventhander (Object sender, eventargs E );
Public class userlogin: system. Windows. Forms. usercontrol
{
Private string username, password;
Private system. Windows. Forms. groupbox groupbox1;
Private system. Windows. Forms. Button buttoncancel;
Private system. Windows. Forms. Button buttonok;
Private system. Windows. Forms. textbox textboxpwd;
Private system. Windows. Forms. Label label2;
Private system. Windows. Forms. Label label1;
Private system. Windows. Forms. textbox textboxuid;
/// <Summary>
/// Required designer variables.
/// </Summary>
Private system. componentmodel. Container components = NULL; Public userlogin ()
{
// This call is required by the windows. Forms Form Designer.
Initializecomponent (); // todo: add any initialization after initializecomponent is called.} // <summary>
/// Clear all resources in use.
/// </Summary>
Protected override void dispose (bool disposing)
{
If (disposing)
{
If (components! = NULL)
{
Components. Dispose ();
}
}
Base. Dispose (disposing );
} # Code generated by the region component designer
/// <Summary>
/// The designer supports the required methods-do not use the code editor
/// Modify the content of this method.
/// </Summary>
Private void initializecomponent ()
{
This. groupbox1 = new system. Windows. Forms. groupbox ();
This. buttoncancel = new system. Windows. Forms. Button ();
This. buttonok = new system. Windows. Forms. Button ();
This. textboxpwd = new system. Windows. Forms. Textbox ();
This. label2 = new system. Windows. Forms. Label ();
This. label1 = new system. Windows. Forms. Label ();
This. textboxuid = new system. Windows. Forms. Textbox ();
This. groupbox1.suspendlayout ();
This. suspendlayout ();
//
// Groupbox1
//
This. groupbox1.controls. Add (this. buttoncancel );
This. groupbox1.controls. Add (this. buttonok );
This. groupbox1.controls. Add (this. textboxpwd );
This. groupbox1.controls. Add (this. label2 );
This. groupbox1.controls. Add (this. label1 );
This. groupbox1.controls. Add (this. textboxuid );
This. groupbox1.location = new system. Drawing. Point (8, 2 );
This. groupbox1.name = "groupbox1 ";
This. groupbox1.size = new system. Drawing. Size (200, 96 );
This. groupbox1.tabindex = 6;
This. groupbox1.tabstop = false;
//
// Buttoncancel
//
This. buttoncancel. Location = new system. Drawing. Point (112, 71 );
This. buttoncancel. Name = "buttoncancel ";
This. buttoncancel. size = new system. Drawing. Size (56, 20 );
This. buttoncancel. tabindex = 11;
This. buttoncancel. Text = "& cancel ";
This. buttoncancel. Click + = new system. eventhandler (this. buttoncancel_click );
//
// Buttonok
//
This. buttonok. Location = new system. Drawing. Point (32, 71 );
This. buttonok. Name = "buttonok ";
This. buttonok. size = new system. Drawing. Size (56, 20 );
This. buttonok. tabindex = 10;
This. buttonok. Text = "& OK ";
This. buttonok. Click + = new system. eventhandler (this. buttonok_click );
//
// Textboxpwd
//
This. textboxpwd. Location = new system. Drawing. Point (72, 43 );
This. textboxpwd. Name = "textboxpwd ";
This. textboxpwd. passwordchar = *;
This. textboxpwd. size = new system. Drawing. Size (112, 21 );
This. textboxpwd. tabindex = 9;
This. textboxpwd. Text = "";
This. textboxpwd. textchanged + = new system. eventhandler (this. textboxpwd_textchanged );
//
// Label2
//
This. label2.location = new system. Drawing. Point (9, 42 );
This. label2.name = "label2 ";
This. label2.size = new system. Drawing. Size (64, 23 );
This. label2.tabindex = 8;
This. label2.text = "Password :";
This. label2.textalign = system. Drawing. contentalignment. middlecenter;
//
// Label1
//
This. label1.location = new system. Drawing. Point (9, 14 );
This. label1.name = "label1 ";
This. label1.size = new system. Drawing. Size (64, 23 );
This. label1.tabindex = 7;
This. label1.text = "username :";
This. label1.textalign = system. Drawing. contentalignment. middlecenter;
//
// Textboxuid
//
This. textboxuid. Location = new system. Drawing. Point (72, 15 );
This. textboxuid. Name = "textboxuid ";
This. textboxuid. size = new system. Drawing. Size (112, 21 );
This. textboxuid. tabindex = 6;
This. textboxuid. Text = "";
This. textboxuid. textchanged + = new system. eventhandler (this. textboxuid_textchanged );
//
// Userlogin
//
This. Controls. Add (this. groupbox1 );
This. Name = "userlogin ";
This. size = new system. Drawing. Size (216,104 );
This. groupbox1.resumelayout (false );
This. resumelayout (false );}
# Endregion
// Define attributes
Public String Username
{
Get {return username ;}
Set {username = value ;}
}
Public String Password
{
Get {return password ;}
Set {Password = value ;}
}

// Define the event
Public event btnokclickeventhander btnokclick;
Public event btncancelclickeventhander btncancelclick;
Private void textboxuid_textchanged (Object sender, system. eventargs E)
{
Username = This. textboxuid. text;
} Private void textboxpwd_textchanged (Object sender, system. eventargs E)
{
Password = This. textboxpwd. text;
} Private void buttonok_click (Object sender, system. eventargs E)
{
If (btnokclick! = NULL)
Btnokclick (this, e );
} Private void buttoncancel_click (Object sender, system. eventargs E)
{
If (btncancelclick! = NULL)
Btncancelclick (this, e );
}

}
}