C# thread method return a value? [duplicate]

Answer 1

Not only does ThreadStart expect void methods, it also expect them not to take any arguments! You can wrap it in a lambda, an anonymous delegate, or a named static function.

Here is one way of doing it:

string res = null;
Thread newThread = new Thread(() => {res = sayHello("world!");});
newThread.Start();
newThread.Join(1000);
Console.Writeline(res);

Here is another syntax:

Thread newThread = new Thread(delegate() {sayHello("world!");});
newThread.Start();

The third syntax (with a named function) is the most boring:

// Define a "wrapper" function
static void WrapSayHello() {
    sayHello("world!);
}

// Call it from some other place
Thread newThread = new Thread(WrapSayHello);
newThread.Start();

Answer 2

You should be using a Task for that purpose.

Answer 3

If you can use any method of threading, try BackgroundWorker:

BackgroundWorker bw = new BackgroundWorker();
public Form1()
{
    InitializeComponent();

    bw.DoWork += bw_DoWork;
    bw.RunWorkerCompleted += bw_RunWorkerCompleted;
    bw.RunWorkerAsync("MyName");
}

void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    Text = (string)e.Result;
}

void bw_DoWork(object sender, DoWorkEventArgs e)
{
    string name = (string)e.Argument;
    e.Result = "Hello ," + name;
}