c# 設置並發線程數量

CancellationTokenSource cts = new CancellationTokenSource();
ParallelOptions pOptions = new ParallelOptions() { CancellationToken = cts.Token };
pOptions.MaxDegreeOfParallelism = 3;//設置並發線程數量

Parallel.For(0, 100, pOptions, i =>
{
    
});