Use object from MainForm in Class

Question

I'm writing a application in C# WPF.

I am having a small issue here.

In the class.cs, I have a line:

MessageBox.Show("Cancelled sending !");

And on my form I have a radioButton1.

How can I make it like

if (radioButton1.IsChecked == true)
{
    MessageBox.Show("Cancelled sending !");
}

Because when I try it, it doesn't find the radioButton1

I have tried it different ways, but I can't find how to do it.

Just to make sure: are we really talking about WPF application? If so, please post your XAML. Also, when you say "class.cs", do you mean class.xaml.cs? — Somedust, Nov 28 '13 at 12:39
No, i mean the: Right Click Your Project->Add->New Item->Class1.cs — user2944342, Nov 28 '13 at 12:45
Well, in that case your class is simply not aware of the radio button presence. Are you trying the MVVM approach? I.e. is class.cs acting as a view-model? — Somedust, Nov 28 '13 at 12:48
@progpow It won't help as he isn't even working with codebehind. — Somedust, Nov 28 '13 at 13:11
@Somedust it`s not working at code because he wrong define it at xaml. — progpow, Nov 28 '13 at 18:56
@progpow No, it isn't. If you don't know the difference between Name and x:Name, you can always Google it. First search result: http://stackoverflow.com/questions/589874/in-wpf-what-are-the-differences-between-the-xname-and-name-attributes — Somedust, Nov 29 '13 at 06:42

score 0 · Answer 1 · answered Nov 28 '13 at 12:41

0

If I understand you correct, you are trying to access the value of your radioButton in your class.cs, right? If so, you can make a public property, which encapsulates your radiobutton-checked-property.

This can look like:

public bool IsRadioButtonChecked
{
   get{return radioButton1.IsChecked;}
}

In your class.cs you need an instance of the window.

answered Nov 28 '13 at 12:41

Tomtom

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WPF RadioButton doesn't seem to expose Checked property, only the IsChecked one. – Somedust Nov 28 '13 at 12:45
Sorry. Mixed up WinForms and WPF – Tomtom Nov 28 '13 at 12:46

score 0 · Answer 2 · answered Nov 28 '13 at 12:46

The radio button that you created on your form is stored in a private variable in the MainForm class. Therefore, it is inaccessible from other classes.

You could turn it into a public variable, but this is not a very good approach, and in any case, will be overwritten by the Forms designer as you add/remove/resize controls on the form.

The better solution would be to pass the reference to the radio button to your other class, either via the constructor, or as an argument to the method that is checking the status of the radio button (if it is invoked by the form).

For example:

public class MyClass {
    private mRbutton;

    public MyClass(RadioButton rbutton) {
        mRbutton = rbutton;
        // Rest of the construction code...
    }

    //
    // ... Rest of the class code ...
    //

    public void MessageShowingMethod() {
        if (mRbutton.IsChecked == true) {
            MessageBox.Show("Cancelled sending !");
        }
    }
}

If he was doing a windows form project this would be correct. Mind you, sure it will work in wpf just as well, but its not really in line with the whole mvvm thing, is it? — hschne, Nov 28 '13 at 12:50

score 0 · Answer 3 · answered Nov 28 '13 at 12:51

Try this maybe. In your main form:

if (radioButton1.IsChecked == true)
{
  int checked = 1;
}

callMyMethod(checked);

And then in your class.cs:

public callMyMethod(int checked)
{
  if (checked == 1)
  {
    MessageBox.Show("Cancelled sending !");
  }
  else
  {
    MessageBox.Show("Something else");
  }
}

score 0 · Answer 4 · answered Nov 28 '13 at 13:03

When using WPF, we have Window and UserControl classes, among other things. These are partial classes, which means that they have more than one file in them. There is a .xaml file where we define the UI and a code behind .xaml.cs file where we can access the named UI elements that we defined in the related .xaml file. You should never access a UI element in any other class.

To access a UI element in the code behind file, you must first name it in the .xaml file:

<RadioButton Name="RadioButton" />

Then, in the code behind file only, you can access it using that name:

if (RadioButton.IsChecked)
{
    MessageBox.Show("Cancelled sending !");
}

Once again, you should never access a UI element in any other class.

Use object from MainForm in Class

4 Answers4