[英]Index (zero based) must be greater than or equal to zero
嘿,我不斷收到錯誤消息:
索引(從零開始)必須大於或等於零且小於參數列表的大小。
我的代碼:
OdbcCommand cmd = new OdbcCommand("SELECT FirstName, SecondName, Aboutme FROM User WHERE UserID=1", cn);
OdbcDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
Name.Text = String.Format("{0} {1}", reader.GetString(0), reader.GetString(1));
Aboutme.Text = String.Format("{2}", reader.GetString(0));
}
您的第二個String.Format
使用{2}
作為占位符,但您只傳入一個參數,因此您應該改用{0}
。
改變這個:
String.Format("{2}", reader.GetString(0));
對此:
String.Format("{0}", reader.GetString(2));
在這一行:
Aboutme.Text = String.Format("{2}", reader.GetString(0));
令牌 {2} 無效,因為參數中只有一項。 改用這個:
Aboutme.Text = String.Format("{0}", reader.GetString(0));
改變這一行:
Aboutme.Text = String.Format("{0}", reader.GetString(0));
當您在無意中調用ArgumentException
構造函數重載時嘗試拋出ArgumentException
時也會發生這種情況
public static void Dostuff(Foo bar)
{
// this works
throw new ArgumentException(String.Format("Could not find {0}", bar.SomeStringProperty));
//this gives the error
throw new ArgumentException(String.Format("Could not find {0}"), bar.SomeStringProperty);
}
String.Format 必須以零索引“{0}”開頭,如下所示:
Aboutme.Text = String.Format("{0}", reader.GetString(0));
using System;
namespace ConsoleApp1
{
class Program
{
static void Main()
{
Console.WriteLine("Enter Your FirstName ");
String FirstName = Console.ReadLine();
Console.WriteLine("Enter Your LastName ");
String LastName = Console.ReadLine();
Console.ReadLine();
Console.WriteLine("Hello {0}, {1} ", FirstName, LastName);
Console.ReadLine();
}
}
}
改變這一行:
2 應該是 0。每個計數都從 0 開始。
//Aboutme.Text = String.Format("{2}", reader.GetString(0));//wrong
//Aboutme.Text = String.Format("{0}", reader.GetString(0));//correct
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