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This article mainly introduces how to achieve the interaction between WinForm forms, the article introduces in great detail, has a certain reference value, interested friends must read it!

There are many ways to pass data between forms:

1. Customize a constructor in the sub-form, and the parameter type is the main form. When you want to display the sub-form, use this constructor to instantiate the sub-form, and then pass the this pointer in. It is too abstract. You should understand it as soon as I write it:

Public class frmMain:Form {... FrmControl controlForm=new frmControl (this); controlForm.Show ();} public class frmControl:Form / / Sub-form, which is used to control some display of the main form! {private frmMain mainForm; public frmControl (frmMain mainForm) {this.mainForm=mainForm;} private void button1_Click (object sender,EventArgs e) {frmMain.textBox1.Text=this.textBox1.Text; / / pass the text box value of the sub-form to the text box of the main form! }}

2. I personally feel that the above method is not very good, although it is easy to implement. If you just want to change the title text of the form, pass the reference of the entire main form to the sub-form, which is not very elegant. We use the interface to improve the above method, which can limit the functions exposed to the sub-form and reduce the coupling between the forms:

Public interface IChangeTitle: {void ChangeTitle (string title);} public class frmMain:Form,IChangeTitle {... FrmControl controlForm=new frmControl (this); controlForm.Show (); public void ChangeTitle (string title) {this.Text=title;}} public class frmControl:Form / / Sub-form, which is used to control some display of the main form! {private IChangeTitle ichangeTitle; public frmControl (IChangeTitle ichangeTitle) {this.ichangeTitle=ichangeTitle;} private void button1_Click (object sender,EventArgs e) {ichangeTitle.ChangeTitle (this.textBox1.Text); / / call the method through the interface}}

3. To further reduce the coupling between forms, we can use delegates to achieve this requirement:

Public partial class ChildForm: Form {public delegate void TitleChangedHandler (string title); public TitleChangedEventHandler TitleChanged; public ChildForm () {InitializeComponent ();} private void btn_Ok_Click (object sender, EventArgs e) {if (TitleChanged! = null) TitleChanged ("Test Title") / / delegate call}}

The main form assigns a value to the delegate variable:

Public partial class MainForm: Form {private ChildForm loginForm = new ChildForm (); public MainForm () {InitializeComponent (); loginForm.TitleChanged = new ChildForm.TitleChangedEventHandler (FormTitleChanged);} protected void FormTitleChanged (string title) {this.Text = title } private void button1_Click (object sender, EventArgs e) {loginForm.Show ();}}

4, you can also define a custom event in the sub-form, and then customize an event parameter to convey some of the information you want to convey:

Public partial class ChildForm: Form {public class TitleChangedEventArgs: EventArgs / / event parameter class {private string title = ""; public string Title {get {return title } set {title = value;} public delegate void TitleChangedEventHandler (object sender, TitleChangedEventArgs e); public event TitleChangedEventHandler TitleChanged; public ChildForm () {InitializeComponent () } private void btn_Ok_Click (object sender, EventArgs e) {TitleChangedEventArgs e1=new TitleChangedEventArgs (); e1.Title = "Login sucessed"; OnTitleChanged (E1) / / trigger event} protected virtual void OnTitleChanged (TitleChangedEventArgs e) / / method to trigger event {if (TitleChanged! = null) TitleChanged (this, e);}}

The main form can subscribe to this event:

Public partial class MainForm: Form {private ChildForm loginForm = new ChildForm (); public MainForm () {InitializeComponent (); loginForm.TitleChanged + = new ChildForm.TitleChangedEventHandler (FormTitleChanged);} protected void FormTitleChanged (object sender, ChildForm.TitleChangedEventArgs e) {this.Text = e.Title } private void button1_Click (object sender, EventArgs e) {loginForm.Show ();}} above is all the content of the article "how to implement interaction between WinForm forms". Thank you for reading! Hope to share the content to help you, more related knowledge, welcome to follow the industry information channel!

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