SqlCommand cmd = new SqlCommand("Select * from UserInfo where UserName= '" + UserName + "'", connect);

不是你问题的解决方案，而是你遇到的另一个问题。

永远不要通过连接字符串来构建SQL查询。迟早，您将使用用户输入来执行此操作，这会打开一个名为SQL注入的漏洞，这对您的数据库很容易并且容易出错。

名称中的单引号你的程序崩溃。如果用户输入像Brian O'Conner这样的名称可能会使您的应用程序崩溃，那么这是一个SQL注入漏洞，崩溃是最少的问题，恶意用户输入，并且它被提升为具有所有凭据的SQL命令。

SQL注入 - *** [ ^ ]

SQL注入 [ ^ ]

按示例进行SQL注入攻击 [ ^ ]

PHP：SQL注入 - 手册 [ ^ ]

SQL注入预防备忘单 - OWASP [ ^ ]

Not a solution to your question, but another problem you have.
Never build an SQL query by concatenating strings. Sooner or later, you will do it with user inputs, and this opens door to a vulnerability named "SQL injection", it is dangerous for your database and error prone.
A single quote in a name and your program crash. If a user input a name like "Brian O'Conner" can crash your app, it is an SQL injection vulnerability, and the crash is the least of the problems, a malicious user input and it is promoted to SQL commands with all credentials.
SQL injection - Wikipedia[^]
SQL Injection[^]
SQL Injection Attacks by Example[^]
PHP: SQL Injection - Manual[^]
SQL Injection Prevention Cheat Sheet - OWASP[^]

好的，您正在调用名为tbl_User_SelectRow的数据库中的存储过程，该存储过程需要传入一个参数，称为@UserName。您的代码不提供该参数。



快速Google C＃sql参数化查询 [ ^ ]有大量有关如何操作的信息。

OK, you're calling a stored procedure in the database called "tbl_User_SelectRow" which expects a parameter to be passed in, called "@UserName". You're code doesn't supply that parameter.

A quick Google for "C# sql parameterized query[^]" has tons of information on how to do it.

业务逻辑通常验证在发布到数据库之前。示例：

Business Logic usually validates before posting to the DB. Example:

if (!string.IsNullOrEmpty(UserNameTextBox.Text)
{
    bll.UserName = UserNameTextBox.Text;
    bll.bl_bind();
    if (bll.UserTyp == 0)
    {
        Response.Redirect("~/ShowMessage.aspx");
    }
else
{
   // handle invalid (empty) username...
}