并非所有的代码路径都返回值.程序应该怎么改？

[懦芞]

public int CheckUser()
{
if (this.tbxUserName.Text == "")
{
MessageBox.Show("用户名不能为空！", "错误");
}
else if (this.tbxPassWord.Text == "")
{
MessageBox.Show("密码不能为空！", "错误");
}
else
{
string str = System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"];
SqlConnection conn = new SqlConnection(str);
SqlCommand cmd = new SqlCommand("Login", conn);

cmd.CommandType = CommandType.StoredProcedure;
SqlParameter UserName = new SqlParameter("@username", SqlDbType.VarChar, 50);
UserName.Value = this.tbxUserName.Text;
cmd.Parameters.Add(UserName);

SqlParameter PassWord = new SqlParameter("@pwd", SqlDbType.VarChar, 50);
UserName.Value = this.tbxPassWord.Text;
cmd.Parameters.Add(PassWord);

SqlParameter sp = new SqlParameter("@return", SqlDbType.Int, 4);

sp.Direction = ParameterDirection.Output;
cmd.Parameters.Add(sp);

try
{
conn.Open();
cmd.ExecuteNonQuery();
conn.Close();
int n = (int)(sp.Value);
return n;
}
catch
{
return 0;
}
}
}
private void button1_Click(object sender, EventArgs e)
{
if (CheckUser() > 0)
{
PicManager pic = new PicManager();
pic.Show();
this.Hide();
}
else
{
MessageBox.Show("用户名不能为空");
}
}

[懦芞]

自己先顶顶

[wkishappy]

CheckUser()最后一个大括号之前写上一句：return 0;

[wuyi8808]

        public int CheckUser() 
        { 
            if (this.tbxUserName.Text == "") 
            { 
                MessageBox.Show("用户名不能为空！", "错误"); 
            } 
            else if (this.tbxPassWord.Text == "") 
            { 
                MessageBox.Show("密码不能为空！", "错误"); 
            } 
            else 
            { 
                string str = System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"]; 
                SqlConnection conn = new SqlConnection(str); 
                SqlCommand cmd = new SqlCommand("Login", conn); 

                cmd.CommandType = CommandType.StoredProcedure; 
                SqlParameter UserName = new SqlParameter("@username", SqlDbType.VarChar, 50); 
                UserName.Value = this.tbxUserName.Text; 
                cmd.Parameters.Add(UserName); 

                SqlParameter PassWord = new SqlParameter("@pwd", SqlDbType.VarChar, 50); 
                UserName.Value = this.tbxPassWord.Text; 
                cmd.Parameters.Add(PassWord); 

                SqlParameter sp = new SqlParameter("@return", SqlDbType.Int, 4); 

                sp.Direction = ParameterDirection.Output; 
                cmd.Parameters.Add(sp); 

                try 
                { 
                    conn.Open(); 
                    cmd.ExecuteNonQuery(); 
                    conn.Close(); 
                    int n = (int)(sp.Value); 
                    return n; 
                } 
                catch 
                { 
                    return 0; 
                } 
            }

            return 0;  // <---- 最后加上这句！
 
        } 

[qq904492758]

MessageBox.Show("用户名不能为空！", "错误");
加上 return 0;

MessageBox.Show("密码不能为空！", "错误");
加上 return 0;

[qq904492758]

mark

[qq904492758]

我晕 。。一分没有啊