如何在c#窗口窗体中检索按钮单击后已分配的当前值

本文关键字：分配 单击 按钮 窗口 窗体 检索 | 更新日期: 2023-09-27 18:17:13

. NET我可以使用会话，但对于windows窗体，我如何获得当前值，我可以添加+ 1?

在btnPrintToken点击后，它将重写，重新运行代码，我希望它保持最后输入的值(LastTokenNumberIssued)，并为它添加+ 1等，以便它将更新队列。

private void btnPrintToken_Click(object sender, EventArgs e)
{
    Queue<int> queueTokens = new Queue<int>();
    lblStatus.Text = "There are " + queueTokens.Count.ToString() +
        " customers before you in the queue";
    int LastTokenNumberIssued = // Not sure how to retrieve current value what it was after nextTokenNumberTobeIssued.
    int nextTokenNumberTobeIssued = LastTokenNumberIssued + 1;
    LastTokenNumberIssued = nextTokenNumberTobeIssued;
    queueTokens.Enqueue(nextTokenNumberTobeIssued);
    AddTokensToListBox(queueTokens);
}
private void AddTokensToListBox(Queue<int> queueTokens)
{
    listTokens.Items.Clear();
    foreach (int token in queueTokens)
    {
        listTokens.Items.Add(token.ToString());
    }
}

如何在c#窗口窗体中检索按钮单击后已分配的当前值

在方法之外创建您的LastTokenNumberIssued:

public YourWindow 
{
   int LastTokenNumberIssued;
   private void btnPrintToken_Click(object sender, EventArgs e)
   {
      int nextTokenNumberIssued;
      LastTokenNumberIssued = LastTokenNumberIssued++;
      nextTokenNumberTobeIssued = LastTokenNumberIssued;
   }
}

如果你在方法中创建lasttokennumberissue，它会在每次点击按钮时被重写，因为当方法返回时它的值会丢失。

查看方法作用域的更多信息

一种方法是在btnPrintToken_Click方法之前定义这些变量nextTokenNumberTobeIssued, LastTokenNumberIssued，如下所示:

int LastTokenNumberIssued = 0; //give it a default value here.
int nextTokenNumberTobeIssued = 0; //give it a default value here.
private void btnPrintToken_Click(object sender, EventArgs e)
{
    ....
    nextTokenNumberTobeIssued = LastTokenNumberIssued + 1;
    LastTokenNumberIssued = nextTokenNumberTobeIssued;
    ...
}

这样，每次用户点击按钮PrintToken，你将有LastTokenNumberIssued保持之前的点击。

 int LastTokenNumberIssued = 0; //here will be the start value
 private void btnPrintToken_Click(object sender, EventArgs e)
 {
    Queue<int> queueTokens = new Queue<int>();
    lblStatus.Text = "There are " + queueTokens.Count.ToString() +
        " customers before you in the queue";
    int nextTokenNumberTobeIssued = LastTokenNumberIssued + 1;
    LastTokenNumberIssued = nextTokenNumberTobeIssued;
    queueTokens.Enqueue(nextTokenNumberTobeIssued);
    AddTokensToListBox(queueTokens);
}
private void AddTokensToListBox(Queue<int> queueTokens)
{
    listTokens.Items.Clear();
    foreach (int token in queueTokens)
    {
        listTokens.Items.Add(token.ToString());
    }
}
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