目的：
多個按鈕點擊新建線程執行某個任務。實現多線程執行任務，總數不超過某個數值，超過則等待執行完成纔可以再次點擊。
編程思路：
使用原子鎖計算當前線程總數、線程Join 等待執行完畢。
public class test
{
...
private int threadCount = 0; //當前線程總數
private int maxThreadCount = 5; //一次最多5個工作線程
List<Thread> threads = new List<Thread>(); //保存所有的工作線程
public ThreadFunc_1(Object param)
{
...
Interlocked.Decrement(ref threadCount);
return;
}
public ThreadFunc_2(Object param)
{
...
Interlocked.Decrement(ref threadCount);
return;
}
private void Button1_Click(object sender, EventArgs e)
{
if (threadCount > maxThreadCount)
{
foreach (Thread thread in threads)
{
thread.Join(); //等待
}
threads.Clear();
return;
}
//線程沒有超過上線，則新建線程
Thread t = new Thread(new ParameterizedThreadStart(ThreadFunc_1));
t.isBackgroud = true;
t.Start(param);
threads.Add(t); //保存到線程池
Interlocked.Increment(ref threadCount);
}
private void Button2_Click(object sender, EventArgs e)
{
if (threadCount > maxThreadCount)
{
foreach (Thread thread in threads)
{
thread.Join(); //等待
}
threads.Clear();
return;
}
//線程沒有超過上線，則新建線程
Thread t = new Thread(new ParameterizedThreadStart(ThreadFunc_2));
t.isBackgroud = true;
t.Start(param2);
threads.Add(t); //保存到線程池
Interlocked.Increment(ref threadCount);
}
...
}