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我有一個asp.net的網頁形式的應用程序,當用戶列出用戶名字段它檢查我的數據庫,看看它是否可用,但我遇到的問題是它總是即使不存在,也似乎陷入了存在之中。檢查用戶名可用不起作用
我看過很多視頻,也看過很多文章,但是我根本無法得到它。
我已經在下面提供了我所有的代碼。
配置
<add name="PaydayLunchConnectionString1" connectionString="Data Source=********\*******;Initial Catalog=************;Integrated Security=True"
providerName="System.Data.SqlClient" />
HTML
<asp:GridView ID="tblUsers" runat="server" AutoGenerateColumns="False" CellPadding="4" DataSourceID="SqlUsers" GridLines="None" Width="15%">
<AlternatingRowStyle BackColor="White" />
<Columns>
<asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />
</Columns>
<HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
<RowStyle BackColor="#EFF3FB" />
</asp:GridView>
<asp:SqlDataSource ID="SqlUsers" runat="server" ConnectionString="<%$ ConnectionStrings:PaydayLunchConnectionString1 %>" SelectCommand="SELECT [Name] FROM [Users] WHERE [name] != 'Admin'"></asp:SqlDataSource>
<asp:Label ID="removeUserNotExist" runat="server" Text="The user entered does not exist. Please try again." Visible="false" style="color: red"></asp:Label>
<asp:Label ID="removeUserExists" runat="server" Text="The user entered exists." Visible="false" style="color: green"></asp:Label>
<div class="form-group">
<asp:Label runat="server" AssociatedControlID="txtRemoveUser" CssClass="col-sm-offset-2 col-sm-3 control-label">Enter Name To Be Removed</asp:Label>
<div class="col-sm-3">
<asp:TextBox runat="server" ID="txtRemoveUser" CssClass="form-control" AutoPostBack="true" OnTextChanged="txtRemoveUser_TextChanged" />
</div>
</div>
代碼隱藏
using System.Data.SqlClient;
using System.Configuration;
using System.Data;
protected void txtRemoveUser_TextChanged(object sender, EventArgs e)
{
if (!string.IsNullOrEmpty(txtRemoveUser.Text))
{
string connection = ConfigurationManager.ConnectionStrings["PaydayLunchConnectionString1"].ConnectionString;
SqlConnection conn = new SqlConnection(connection);
conn.Open();
SqlCommand cmd = new SqlCommand("SELECT * FROM Users WHERE Name != @Name", conn);
cmd.Parameters.AddWithValue("@Name", txtRemoveUser.Text);
SqlDataReader rd = cmd.ExecuteReader();
if (rd.HasRows)
{
removeUserNotExist.Visible = true;
removeUserExists.Visible = false;
}
else
{
removeUserNotExist.Visible = false;
removeUserExists.Visible = true;
}
}
}
DB詳細
Table Name = Users
Columns = ID, Name, Password
Users = Test, Test2
如果我在字段中輸入和標籤進行「測試」,我得到正確的信息(存在),但如果我再進入「ABC」我仍然得到「存在」的消息。
廣東話相信這是那麼容易。只是有一點盲目的代碼,無法讓我的頭繞過我所做的事情 – murday1983