c# - 如何用逗号字符分隔字符串？

Question

我想用逗号分隔两个字符串(即 234,229)，我尝试通过添加 String.Join() 来实现。我有下面提到的代码，在最后一行出现错误。我知道这是一个基本问题，但我是 C# 编程语言的新手。

 string queryEventID = "";
    foreach (ListItem lstAssign in lstEvent.Items)
    {
       if (lstAssign.Selected == true)
         {                  
            queryEventID = queryEventID + lstAssign.Value + " "; //queryEventID(234 229)                   
            logfield = logfield + "," + lstEvent.SelectedItem.Text;
         }
    }                     
    string queryEventIDs=string.Join(",",queryEventID);//error(cannot convert from string to string[])

Answer 1

您应该使用Collection 来申请string.Join .

来自文档:

Join(String, String[]): Concatenates all the elements of a string array, using the specified separator between each element.

这是一个如何在您的情况下使用它的示例。

List<string> queryEventIDList;
foreach (ListItem lstAssign in lstEvent.Items)
{
    if (lstAssign.Selected == true)
    {
        queryEventIDList.Add(lstAssign.Value);                 
        logfield = logfield + "," + lstEvent.SelectedItem.Text;
    }
}
string queryEventIDs = string.Join(",", queryEventIDList);