Loop through controls to change seletionStart for each

[tonymuilenburg]

Hi, I'm trying to loop through multiple textboxes in a C++ form using visual studio.net 2008 to set the selection start for each. The code for a single textbox is easy:

textBox1->SelectionStart = 4;

When I try to assign textBox1 to a Control variable, and assign selection start, I get an error:

Control^ myControl;
myControl = textBox1;
myControl->SelectionStart = 4;

The error says:
error c2039: 'SelectionStart' : is not a member of 'System::Windows::Forms::Control'

I have no trouble assigning text this way:

Control^ myControl;
myControl = textBox1;
myControl->Text = "hello";

Does anyone know how I can do this?

[jonsca]

SelectionStart is a property specific to TextBox. Text is a property that all Controls have. To access that property you need to downcast the controls to their particular type using a dynamic_cast to TextBox^ type. You'll have to do some checking to make sure that you have the right controls on your form, perhaps by tagging your textboxes and using that as a criterion to cast them.

[jonsca]

Here's an example that gives you something tangible when you click the button. Set the "Tag" property of each of the textboxes to "Text" (or some other moniker).

private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {
	for(int i = 0;i<Controls->Count;i++)
		if(Controls[i]->Tag=="Text")	 
		{
	  	  dynamic_cast<TextBox^>(Controls[i])->Multiline = true;
		   dynamic_cast<TextBox^>(Controls[i])->Height = 5;
		}
}

[tonymuilenburg]

Here's an example that gives you something tangible when you click the button. Set the "Tag" property of each of the textboxes to "Text" (or some other moniker).

private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {
	for(int i = 0;i<Controls->Count;i++)
		if(Controls[i]->Tag=="Text")	 
		{
	  	  dynamic_cast<TextBox^>(Controls[i])->Multiline = true;
		   dynamic_cast<TextBox^>(Controls[i])->Height = 5;
		}
}

Wow, this works perfectly, Thanks!
Tony