How to implement this scenario in wpf - wpf

Question

I'm allowing two instance of wpf application
private void Application_Startup(object sender, StartupEventArgs e)
{
Process thisProc = Process.GetCurrentProcess();
if (Process.GetProcessesByName(thisProc.ProcessName).Length == 1)
{
var w1 = new MainWindow("1");
w1.Show();
}
else if (Process.GetProcessesByName(thisProc.ProcessName).Length == 2)
{
var w2 = new MainWindow("2");
w2.Show();
}
}
Each window having different user setting like below
In Settings.setting
window1_city="xxx",window1_country="yyy"
window2_city="aaa",window2_country="bbb" .....etc
I want to apply the above settings on windows load(in constructor).
My current code is
public MainWindow(string window)
{
if(window=="1")
{
lbl.Content=setting.window1_city
}
if(window=="2")
{
lbl.Content=setting.window2_city
}
}and so
But this is very difficult to apply if no.of user settings more. If user made any changes then I've to save those values according to window. So I've to use more no.of if loops.
Is there any other way to implement this?

Answer 1

Use each window DataContext property to pass an object with all property needed, pass that object in the Startup, before Show.
Maybe you would better use some MVVM toolkit, if the app is going to be more complex.
An example in using plain DataContextes:
private void Application_Startup(object sender, StartupEventArgs e)
{
Process thisProc = Process.GetCurrentProcess();
if (Process.GetProcessesByName(thisProc.ProcessName).Length == 1)
{
var w1 = new MainWindow("1");
var a = new MySettings();
a.x=...;
a.y=....;
w1.DataContext=a;
w1.Show();
}
else if (Process.GetProcessesByName(thisProc.ProcessName).Length == 2)
{
var w2 = new MainWindow("2");
var b = new MySettings();
b.x=...;
b.y=....;
w2.DataContext=b;
w2.Show();
}
}