Threading with parameters fails

Question

I have following code:

Thread userThread = new Thread(() => UserPasswordSpawn.InputBox(ref userName, ref password));
//UserPassWordSpawn.InputBox(ref userName, ref password);
/* do some calculations while user puts in data */

userThread.Join();

The thread does not work, and never enters the InputBox() function (I set a breakpoint there, and it is never reached), while it works just fine if I do the commented part (but the calculations which should happen while the system is waiting for the user to input the data). How can I spawn a thread with 2 input parameters properly (twice ref string).

Note, the error I get is something about Thread.JoinInternal(), but the main thing is probably that the function is not called.

The call with the () => ThreadStart() I got from How to pass parameters to ThreadStart method in Thread?

you are not starting the thread.why not use tpl.threads created like this are costly — Prabhu Murthy, Nov 21 '12 at 11:19
I do not see a userThread.start(). Can you include that part of your code as well ? — Ravi Y, Nov 21 '12 at 11:20

score 3 · Accepted Answer · answered Nov 21 '12 at 11:20

3

By this:

Thread userThread = new Thread(() => UserPasswordSpawn.InputBox(ref userName, ref password));

you've created new thread instance.
Now you should start it by in a way like that:

userThread.Start();

answered Nov 21 '12 at 11:20

alex.b

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Thanks, that was indeed the reason. Somehow I am used to C++, where that is not needed explicitly. – SinisterMJ Nov 21 '12 at 11:25

score 3 · Answer 2 · answered Nov 21 '12 at 11:20

3

Call userThread.Start(); after creating the thread, and before joining it.

answered Nov 21 '12 at 11:20

Marc Gravell

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Threading with parameters fails

2 Answers2