setting textbox text onto a child Form

setting textbox text onto a child Form

• behnamkh

  Yes that helps. I've figured out that I need to pass the pointer to the textBox to function X.
  Here's what works :
  
  function X definition :
  X(System::Windows::Forms::TextBox* box, .....)
  {.....
       box->set_Text(S"hi");
  ....}
  
  inside Form2, the function X is called :
  
   X(textBox1, ....);
  
  The only thing left is to pass a group of textBox pointers to function X. Should I create a struct or enum of pointers How will I call function X inside Form2
  
  ak
  
  

• Mark Dostie

  IMHO making the control public is really a hack, making a set function public and from within the function you can have it set the Text property of the textbox is a more OO compilant way. But it is your call :).
  
  The problem you metion above is really due to the fact that the pointer to a Form2 object is defined but no actual Form2 object instances has been assigned to it unless you give it a valid address the error will still pop-up.
  
  Say in one of the parameter you have BOOL X ( Form2* _theForm,z, //other params) then you do Form2* pForm2 = _theForm; then the pForm2 pointer is properly pointing to an object, of coz you have to have Form2 constructed before calling this function X.
  
  Again, I have a feeling you are breaking encapsulation everwhere, if you want to do what you want. However, I would not recomment as it one of the problem OO wants to fix. But come back to your question, you can make myFrom2 as a global and public variable, so that function X can access the form anywhere.
  
  Hope this helps.
  Stardust
  
  
  

• Arturo_RX7

   I think I'm close :
  
  I have defined textbox1 in the Form2 class as a public, rather than private, member.
  
  The function X looks like this :
  
  BOOL X ( z, //other arguments//)
  {
      Form2* pForm2;
  //more code
      pForm2->textBox1->set_Text(z);
  //more code
  }
  
  Everything compiles :), but when it gets to the pForm2 statement I get an unhandled exception :
  object reference not set to an instance of an object.
  
  Way back inside Form1, Form2 was defined as :
  Form2 *myForm2 = new Form2;
  myForm2->Show();
  
  How can I resolve this
  Is there a way to call myForm2 inside X Should this be done
  
  Any feedback would be most appreciated -
  ak
  
  

• GregA

  Hi there,
  
  So bascally you have 3 objects, Form1, Form2 and SomeClass. Form1 create Form2 and SomeClass wants to access somthing defined in Form2. If I get this far without misunderstand your problem then the following might be your solution:
  
  1. In Form2, make a pubic write only say
  // Sorry I come from a C# background
  public String SetTextBoxText(string _text)
  {
         set{ this.textbox1.Text = _text;}
  }
  
  2. Then modifiy the function X to access Form2.textbox1 as follow:
  public bool X(Form2 _someForm, .......)
  {
      // Some code before this
     _someForm.SetTextBoxText =  "The String you want to display";
    // mode code after this
  }
  
  Hope this helps!!!!
  
  
  
  
  
• setting textbox text onto a child Form