网站会员登录，注册设计

1.前台页面设计（登录）

<form id="form1" runat="server">
         <asp:Label ID="Label1" runat="server" Text="登录名："></asp:Label>
        <asp:TextBox ID="txtUserName" runat="server"></asp:TextBox>
         <asp:Label ID="lbUserName" runat="server" Text=""></asp:Label>
         <br /><br />
        <asp:Label ID="Label2" runat="server" Text="密 码："></asp:Label>
        <asp:TextBox ID="txtUserPass" runat="server"></asp:TextBox><br /><br />
        
        <asp:LinkButton ID="likbtnRegister" runat="server" PostBackUrl="~/DefaultRegister.aspx" CausesValidation="false">注册新用户</asp:LinkButton><br /><br />
        <asp:Button ID="btnLog" runat="server" Text="登录" OnClick="btnLog_Click" />
        <asp:Button ID="btnReset" runat="server" Text="重置" OnClick="btnReset_Click" />
    </form>

2.后天功能代码（登录）

 protected SqlConnection getconnect()
    {
        //读取web.config节点配置
        string strcon = ConfigurationManager.ConnectionStrings["login"].ConnectionString;
        //实例化sqlConnection对象
        SqlConnection con1 = new SqlConnection(strcon);
        return con1;
    }
    /// <summary>
    /// 用户登录
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void btnLog_Click(object sender, EventArgs e)
    {
        if (txtUserName.Text.Trim() == "")
        {
            lbUserName.Text = "用户名不能为空！";
            lbUserName.ForeColor = System.Drawing.Color.Red;
        }
        else
        {
            lbUserName.Text = "";
            //数据库连接
            SqlConnection con = getconnect();
            con.Open();
            //创建sql语句，查询用户输入的用户名和密码是否正确
            string strselect = "select count(*) from tb_userInfo where userName=@username and userPass=@userpass";
            SqlCommand cmd = new SqlCommand(strselect, con);
            // 使用Parameters的Add方法添加参数类型
            cmd.Parameters.Add(new SqlParameter("username", SqlDbType.VarChar, 20));
            //设置Parameters的参数值
            cmd.Parameters["username"].Value = txtUserName.Text;
            cmd.Parameters.Add(new SqlParameter("userpass", SqlDbType.VarChar, 50));
            cmd.Parameters["userpass"].Value = txtUserPass.Text;
            if (Convert.ToInt32(cmd.ExecuteScalar()) > 0)
            {
                Response.Write("<script>alert('登录成功')</script>");
                txtUserName.Text = "";
                txtUserPass.Text = "";
            }
            else
            {
                Response.Write("<script>alert('登录不成功')</script>");
            }
        }
        
    }
    protected void btnReset_Click(object sender, EventArgs e)
    {
        txtUserName.Text = "";
        txtUserPass.Text = "";
    }

1.前台页面设计（注册）

<form id="form1" runat="server">
        <asp:Label ID="Label1" runat="server" Text="用户名"></asp:Label>
        <asp:TextBox ID="txtName" runat="server" OnTextChanged="txtName_TextChanged"></asp:TextBox>
        <asp:Label ID="lbIsName" runat="server" Text=""></asp:Label>
        <asp:RequiredFieldValidator ID="rfvName" runat="server" ErrorMessage="RequiredFieldValidator" ControlToValidate="txtName"></asp:RequiredFieldValidator>
        <br /><br />

        <asp:Label ID="Label2" runat="server" Text="密 码："></asp:Label>
        <asp:TextBox ID="txtPass" runat="server"></asp:TextBox><br /><br />

        <asp:Label ID="Label3" runat="server" Text="昵 称："></asp:Label>
        <asp:TextBox ID="txtNickname" runat="server"></asp:TextBox><br /><br />

        <asp:RadioButtonList ID="redlistSex" runat="server" RepeatDirection="Horizontal">
            <asp:ListItem>男</asp:ListItem>
            <asp:ListItem>女</asp:ListItem>
        </asp:RadioButtonList>

        <asp:Label ID="Label4" runat="server" Text="电 话："></asp:Label>
        <asp:TextBox ID="txtPhone" runat="server"></asp:TextBox><br /><br />

        <asp:Label ID="Label5" runat="server" Text="邮 箱："></asp:Label>
        <asp:TextBox ID="txtEmaile" runat="server"></asp:TextBox><br /><br />

        <asp:Label ID="Label6" runat="server" Text="城 市："></asp:Label>
        <asp:TextBox ID="txtCity" runat="server"></asp:TextBox><br /><br />

        <asp:Button ID="btRegister" runat="server" Text="注册" OnClick="btRegister_Click" />
        <asp:Button ID="btnReturn" runat="server" Text="返回" PostBackUrl="~/DefaultLogin.aspx" CausesValidation="false" />
    </form>

2.后天功能实现（注册） 

protected SqlConnection getconnect()
    {
        //读取web.config节点配置
        string strcon = ConfigurationManager.ConnectionStrings["login"].ConnectionString;
        //实例化sqlConnection对象
        SqlConnection con1 = new SqlConnection(strcon);
        return con1;
    }
    /// <summary>
    /// 自定义一个isName()方法判断用户输入的用户名是否存在
    /// </summary>
    /// <returns></returns>
    protected bool isName()
    {
        bool blisName = false;
        string sqlselect = "select count(*) from tb_userInfo where userName='" + txtName.Text + "'";
        SqlConnection con = getconnect();
        con.Open();
        SqlCommand cmd = new SqlCommand(sqlselect, con);
        // 判断ExecuteScalar方法返回的参数是否大于0，大于0则表示用户名已存在
        if (Convert.ToInt32(cmd.ExecuteScalar()) > 0)
        {
            blisName = true;
        }
        else
        {
            blisName = false;
        }
        return blisName;
    }
    /// <summary>
    /// 先判断用户填写的用户名是否为空，在判断用户名是否存在
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void txtName_TextChanged(object sender, EventArgs e)
    {
        if (txtName.Text == "")
        {
            lbIsName.Text = "用户名不能为空";
            lbIsName.ForeColor = System.Drawing.Color.Red;
        }
        else
        {
            if (isName())
            {
                lbIsName.Text = "用户名已经存在";
                lbIsName.ForeColor = System.Drawing.Color.Red;
            }
            else
            {
                lbIsName.Text = "可以注册";
                lbIsName.ForeColor = System.Drawing.Color.Blue;
            }
        }
    }
    /// <summary>
    /// 注册
    /// </summary>
    /// <param name="ExecuteNonQuery（）">执行SQL语句并返回受影响的行数</param>
    /// <param name="e"></param>
    protected void btRegister_Click(object sender, EventArgs e)
    {
        if (isName())
        {
            lbIsName.Text = "用户名已经存在";
            lbIsName.ForeColor = System.Drawing.Color.Red;
        }
        else
        {
            string username = txtName.Text.Trim();
            string userpass = txtPass.Text.Trim();
            string nickname = txtNickname.Text.Trim();
            string sex = "";
            if (redlistSex.SelectedValue.Trim() == "男")
            {
                sex = "男";
            }
            else
            {
                sex = "女";
            }
            string phone = txtPhone.Text.Trim();
            string emaile = txtEmaile.Text.Trim();
            string city = txtCity.Text.Trim();
            string strinsert = "insert into tb_userInfo(userName,userPass,nickName,sex,phone,emaile,city) values('" + username + "','" + userpass + "','" + nickname + "','" + sex + "','" + phone + "','" + emaile + "','" + city + "')";
            SqlConnection con = getconnect();
            con.Open();
            SqlCommand cmd = new SqlCommand(strinsert, con);
            if (cmd.ExecuteNonQuery() > 0)
            {
                Response.Write("<script>alert('注册成功')</script>");
                txtName.Text = txtPass.Text = txtNickname.Text = txtPhone.Text = txtEmaile.Text = txtCity.Text = "";
            }
            else
            {
                Response.Write("<script>alert('注册失败')</script>");
            }
        }
    }