可能是重复问题：
C#中随机数生成器的工作方式不如我所愿
您好，
以下是我正在编写的一个小应用程序的完整代码 - 它返回一个字母数字代码的ArrayList。我遇到的问题是，当“步进”代码时，每个项目都正确地返回e.Result。然而，如果我让应用程序在没有断点的情况下运行，我只会得到相同变量的多个实例：
public partial class AlphaNum : Form
{
public AlphaNum()
{
InitializeComponent();
// Initialise BackGroundWorker Reporting
backgroundWorker1.WorkerReportsProgress = true;
// Initialise BackGroundWorker Cancel
backgroundWorker1.WorkerSupportsCancellation = true;
}
private void button1_Click(object sender, EventArgs e)
{
backgroundWorker1.RunWorkerAsync();
button1.Enabled = false;
}
private int RandomNumber(int min, int max)
{
Random random = new Random();
return random.Next(min, max);
}
public string RandomString(Random r, int len)
{
string str = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890";
StringBuilder sb = new StringBuilder();
while ((len--) > 0)
sb.Append(str[(int)(r.NextDouble() * str.Length)]);
return sb.ToString();
}
private string generateCode()
{
Random rnd = new Random();
int length = int.Parse(stringLength.Text);
string code = "";
code = RandomString(rnd, length);
return code;
}
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
int quantity = int.Parse(quantityRequired.Text);
ArrayList codes = new ArrayList();
string myText = "";
for (int a = 0; a < quantity; a++)
{
myText = generateCode();
codes.Add(myText);
backgroundWorker1.ReportProgress(((100 / quantity) * a));
}
e.Result = codes;
}
private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
progressBar1.Value = e.ProgressPercentage; //update progress bar
//Console.WriteLine(time);
//in this example, we log that optional additional info to textbox
}
private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
button1.Enabled = true;
ArrayList codes = new ArrayList();
codes = (ArrayList)e.Result;
for (int i = 0; i < codes.Count; i++ )
{
outputText.Text += codes[i].ToString();
outputText.AppendText(Environment.NewLine);
}
}
}
有人能解释一下为什么我通过逐步调试有效地减慢了进程，结果就可以正常，但是在没有停止/减速运行时不正确吗？
非常感谢。