C # Winform Subform access controls and properties of the parent form _c# Tutorial

Today in a contact management of C # design, with this problem, I need to upload the values from the TextBox in the parent form to the subform and query the database, and I used the new parent form (). TextBox.Text; To carry out the value transfer, but without eggs, after many experiments, A simpler solution was found:

A, subform calls a static variable of the parent form

Parent form: Logout

Child form: Affirm

Parent form text box: Tb_logout_username

public partial class Logout:form
{

  //define a static variable that holds the value of the text box in the parent form public

  static string tb_logoutname;

  An event that instantiates a subform

  private void Btt_logout_click (object sender, EventArgs e)
  {

    //Gets the value of the text box in the parent form

    tb_ Logoutname = Tb_logout_username.text;
    Affirm aff = new affirm ();
    Aff. Show ();

  }

Next you can call it in the subform directly: the parent form. Variable

namely: Logout.tb_logoutname

This method is more tricky, it should be found first to get the parent form method, and then operate on it.

Second, pass the parent form as a property to a subform

Define the parent form field for public in your subform, such as:

public class Affirm:form
{public
  Logout mylogout;
}

You can then set its value in the parent form, such as:

public partial class Logout:form
{
 
  //define a static variable that holds the value of the text box in the parent form public
 
  static string tb_logoutname;
 
  An event that instantiates a subform
 
  private void Btt_logout_click (object sender, EventArgs e)
  {
 
    //Gets the value of the text box in the parent form
 
    //tb_ Logoutname = Tb_logout_username.text;
    Affirm aff = new affirm ();
    Aff. Mylogout=this;
    Aff. Show ();
 
  }
 

In this way, the members that are exposed in the parent form can be accessed in the subform, using.