我在做忘记密码，我写下面的代码.但是我得到了错误.那就是size属性的大小为0. [英] i am doing forgotpassword,i write the code below.but i got error .that is the size property has invalid size of 0.

问题描述

public string forgotpassword(string tutor_username, string tutor_email)
{
    SqlConnection con = new SqlConnection(StrCon);
    SqlCommand cmd = new SqlCommand();
    con.ConnectionString = StrCon;
    //DataSet resultds = new DataSet();
    cmd.Connection = con;
    cmd.CommandType = CommandType.StoredProcedure;
    //SqlDataAdapter da = new SqlDataAdapter();
    cmd.CommandText = "tutor_Retrievepassword";
    cmd.Parameters.Add("@tutor_username", SqlDbType.NVarChar).Direction = ParameterDirection.Input;
    cmd.Parameters.Add("@tutor_password", SqlDbType.NVarChar).Direction = ParameterDirection.Output;
    cmd.Parameters.Add("@tutor_email", SqlDbType.NVarChar).Direction = ParameterDirection.Input;
    cmd.Parameters["@tutor_username"].Value = tutor_username;
    //cmd.Parameters["@password"].Value = password;
    cmd.Parameters["@tutor_email"].Value = tutor_email;
    // da.SelectCommand = cmd;
    
    try
    {
        con.Open();
        cmd.ExecuteReader();
        return cmd.Parameters["@tutor_password"].ToString();
        // da.Fill(resultds);
    }
    catch (Exception ex)
    {
        throw ex;
        //  return null;
    }
    finally
    {
        cmd.Dispose();
        con.Close();
        con.Dispose();
    }
    //return resultds;
}

推荐答案

可能应该在存储过程中指定Size参数.

您可以提供tutor_Retrievepassword过程的SQL吗?

Possibly you should specify Size argument in yours stored procedure.

Can you provide SQL of tutor_Retrievepassword procedure?

调试代码以查看哪一行会引发错误.
如果执行查询(cmd.ExecuteReader())
尝试在SQL Server查询分析器上使用相同的参数运行存储过程，并检查存储过程是否成功.

Debug the code to see which line throws the error.
If it''s on execution of query (cmd.ExecuteReader())
try running the stored procedure with same parameters on SQL Server Query Analyzer and check if it succeeds there.

在上面的代码中，您正在使用nvarchar.默认情况下，此数据类型包含1个字符(第一个字符).在这里，如果您在Sql参数中提到了大小，那么您提到的错误将不会出现.您可以尝试查看结果. :)

In the above code you are using nvarchar. This data type by default hold 1 characters(the first one). Here if you mention the size in Sql Parameter, then the error you mentioned will not come. You may try and see the result. :)

这篇关于我在做忘记密码，我写下面的代码.但是我得到了错误.那就是size属性的大小为0.的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！