asp.net - 索引和长度必须引用字符串中的位置。参数名称: length

Question

我收到此错误:

Index and length must refer to a location within the string.
Parameter name: length

使用此代码:

string a1 = ddlweek.Text.Substring(0, 8);                
string a3 = ddlweek.Text.Substring(10, 14);

这是什么意思？

Answer 1

如果字符串的长度(ddlweek)为23个字符或更少，则会出现此错误:

    string ddlweek = "12345678901234567890123";//This is NOK
    string a1 = ddlweek.Substring(0, 8);                
    string a3 = ddlweek.Substring(10, 14);
    Console.WriteLine("a1="+a1);
    Console.WriteLine("a3="+a3);
    Console.ReadLine();

字符串长度至少应为24个字符。
您可以考虑添加if以确保一切正常。

    string ddlweek = "123456789012345678901234";//This is OK
    string a1 = ddlweek.Substring(0, 8);                
    string a3 = ddlweek.Substring(10, 14);
    Console.WriteLine("a1="+a1);
    Console.WriteLine("a3="+a3);
    Console.ReadLine();