How to read the text of the textBox in the overPaint function?

ympcxcs

I defined a new class, and rewritten the onPaint function in the class. The general structure of the class is as follows:
class PlainForm: Form
{
     protected override void OnPaint (PaintEventArgs e)
     {
      ...........
     }
}
There is a textBox in Form1 (the main form). What can I do to read the text value of the textBox in the overPaint function?

wenmy715

Just use TextBox1.Text to get the value.
But why do you want to get this value in OnPaint? Can you tell me your purpose?

yanan13115

Try:
base.TextBox1.Text

ympcxcs

I want to draw a coordinate chart by overriding onPaint, which requires the user to enter some parameters first. If you directly TextBox1.Text, there will be such an error: "Graphic.Form1.textBox1" means "field", which should be "class" here.
If you change to base.TextBox1.Text, an undefined error occurs, is there any way to solve it?

我爱圣骑士

Declare Form1's textBox1 as public.
then
Form1 form1 = new Form1 ();
form1.textBox1.Text = "";
such. It is best to get the value of textBox1 by adding a public method or property to Form1, using the design of MVC.

393736105

this.textBox1.Text

qwer000

Ask, did the textbox have a value before paint?

ympcxcs

Thank you for your help, the value in textBox1 can now be used, but another problem has arisen, if I pre-specify the text value of textBox1 at design time, whatever value you enter at runtime will pass this value, if If you set this value to null during design, you will get the error "The format of the input string is incorrect". What is going on? All depressed and dead.

gtwind3

Is the type wrong?

我爱圣骑士

What does the onPaint function take the value of Textbox for? Generally, the onPaint function does not add any code that has nothing to do with the interface display. What happens when the "input string format is incorrect"?