Compiler errors re: label and textbox

Question

Hi I have placed a button label and a text box on a form. In the button's event handler I have written the following code: int cost; int money; Label->Show(Insert  + cost +  pence); money = textBox->Text; When I try to output text to the label I get the following compiler error: error C2660: 'System::Windows::Forms::Control::Show' : function does not take 1 arguments Also when I try to assign an int variable entered in text box I get following error: error C2440: '=' : cannot convert from 'System::String ^' to 'int'error Even if I try to cast from String to int I get error: money = (int)textBox->Text; C2440: 'type cast' : cannot convert from 'System::String ^' to 'int' I would be grateful if someone could show me how to get round these errors.

Alan · Answer

Hi Ray To ensure that only digits (or backspace) are entered and that Int::Parse won't throw an exception I'd handle the textBox's KeyPress event as follows: private : System::Void textBox_KeyPress(System::Object^ sender System::Windows::Forms::KeyPressEventArgs^ e) { if ((e->KeyChar KeyChar != 8)|| e->KeyChar > 57) { e->Handled = true ; } }

ray dona · Answer

Alan Thanks very much for your help. I forgot to ask a further question. In : if (textBox->Text !=  ) { money = Int32::Parse(textBox->Text); } how can I ensure that each time something is entered it is a digit and if not to reject it.

Alan · Answer

Firstly you need to be setting the Label's Text property rather than calling the Show() method. To convert a numeric string to it's integer representation you can use the static Int32::Parse() method: Label->Text = Insert  + cost +  pence ; if (textBox->Text !=  ) { money = Int32::Parse(textBox->Text); }