Question

I define a stackpanel with 4 TextBlock inside it and I define some object that holds 4 strings as properties.

  class a 
  { 
     public string str1;
     public string str2;
     public string str3;
     public string str4;
  }

  <StackPanel>
     <TextBlock x:Name="txt1" />
     <TextBlock x:Name="txt2" />
     <TextBlock x:Name="txt3" />
     <TextBlock x:Name="txt4" />
  </StackPanel>            

I want to define a binding between the object instance of class a and the stackpanel TextBlock.Text

How can i do it ?

Answer 1

To bind to your str1-4 they have to be get/set Properties at a minimum (and notify properties if they will change after the view is connected to an instance of class a).

 class a 
  { 
     public string str1 { get; set; }
     public string str2 { get; set; }
     public string str3 { get; set; }
     public string str4 { get; set; }
  }

  <StackPanel>
     <TextBlock x:Name="txt1" Text={Binding str1} />
     <TextBlock x:Name="txt2" Text={Binding str2} />
     <TextBlock x:Name="txt3" Text={Binding str3} />
     <TextBlock x:Name="txt4" Text={Binding str4} />
  </StackPanel> 

I do not know where your class a exists, or if you are using MVVM (I am guessing not), but at a minimum in the constructor of the view you need to set the DataContext of the view (or just the stack panel) to your instance of “a”.

e.g.

public MyView()
{
    InitializeComponent();
    this.DataContext = myaInstance;
}

or if you want to target the StackPanel only then name the StackPanel and set its DataContext:

  <StackPanel x:Name="MyStackPanel">

public MyView()
{
    InitializeComponent();
    this.MyStackPanel.DataContext = myaInstance;
}