Multithreading

Suspending a Thread

Threads can be suspended. Suspending a thread stops it temporarily. Working with the example in the previous section, add a new button Button2 to the main form. When this button is clicked the thread is suspended. The code for that looks like this:

Private Sub Button2_Click(ByVal sender as System.Object, ByVal e as System.EventArgs)_ Handles Button2.Click Thread1.Suspend() End Sub

Resuming a Thread

Threads can be resumed after they are suspended. With the example above, add a new button Button3 to the main form. When this button is clicked the thread is resumed from suspension. The code for that looks like this:

Private Sub Button3_Click(ByVal sender as System.Object, ByVal e as System.EventArgs)_ Handles Button3.Click Thread1.Resume() End Sub

Making a Thread Sleep

Threads can be made to sleep which means that they can be suspended over a specific period of time. Sleeping a thread is achieved by passing the time (in milliseconds,1/1000 of a second) to the thread's sleep method. With the example above, add a new button Button4 to the main form. When this button is clicked the thread is stopped. The code for that looks like this:

 

Private Sub Button4_Click(ByVal sender as System.Object, ByVal e as System.EventArgs)_ Handles Button4.Click Thread1.Sleep(100/1000) End Sub

Stopping a Thread

Threads can be stopped with it's abort method. With the example above, add a new button Button5 to the main form. When this button is clicked the thread is stopped. The code for that looks like this:

Private Sub Button5_Click(ByVal sender as System.Object, ByVal e as System.EventArgs)_ Handles Button5.Click Thread1.Abort() End Sub

Thread Priorities

Threads can also be assigned priority for execution. Thread priority can be set by the thread's Priority property and assigning a value from predefined Thread Priority enumeration.

Values for Thread Priority:

Above Normal -> Gives thread higher priority
Below Normal ->Gives thread lower priority
Normal -> Gives thread normal priority
Lowest -> Gives thread lowest priority
Highest -> Gives thread highest priority

Working with the above example, add a new button Button6 to the main form. When this button is clicked the thread is assigned Highest priority .The code for that looks like this:

Private Sub Button6_Click(ByVal sender as System.Object, ByVal e as System.EventArgs)_ Handles Button6.Click Thread1.Priority=System.Threading.ThreadPriority.Highest 'setting Highest priority for the thread End Sub

For more information on Threads please refer to MSDN.