我使用以下代码将所选项目从dropdownlist插入到sql数据库表中。它会运行，但是下拉列表1,2,5和6的所选项始终将第一个项存储在下拉列表中。 这是我的代码
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
//populate gridview
TextBox2.Focus();
string selectquery = "select [TASK ID],[NATURE OF PAYMENT],[DESC],FREQUENCY,PREALERT1,PREALERT2,OWNER,[VERIFICATION OWNER],(case when STATUS='1' then 'Active' when STATUS='0' then 'Inactive' ELSE 'UNKNOWN' END)as STATUS,ID from Compliance_Tracker.dbo.tasklistManager;";
obj6.PopulateGrid(GridView1, selectquery);
}
{
// populate dropdownlist for prealert 1
for (int i = 0; i <= 30; i++)
{
DropDownList3.Items.Insert(i, new ListItem((i + 1).ToString(), (i + 1).ToString()));
}
DropDownList3.DataBind();
}
{
// populate dropdown list for prealert 2
for (int j = 0; j <= 30; j++)
{
DropDownList4.Items.Insert(j, new ListItem((j + 1).ToString(), (j + 1).ToString()));
}
DropDownList4.DataBind();
}
{
//populate dropdown for Nature of Payment
string query = "select * from Compliance_Tracker.dbo.paymentNatureMaster where STATUS='1';";
string columnname = "DESC";
string datavaluefield="DESC";
obj6.PopulateCombo(DropDownList1,query,columnname,datavaluefield);
}
{
//populate dropdown for frequency
string query1 = "select * from Compliance_Tracker.dbo.frequencyMaster where STATUS='1';";
string columnname1 = "DESC";
string datavaluefield1 = "DESC";
obj6.PopulateCombo(DropDownList2,query1, columnname1,datavaluefield1);
}
{
//populate dropdown for owner
string query2 = "select * from Compliance_Tracker.dbo.ownerMaster where STATUS='1';";
string columnname2 = "NAME";
string datavaluefield2 = "NAME";
obj6.PopulateCombo( DropDownList5,query2, columnname2,datavaluefield2);
}
{
//populate dropdown for owner verification
string query3 = "select * from Compliance_Tracker.dbo.verificationMaster where STATUS='1'";
string columnname3 = "NAME";
string datavaluefield3 = "NAME";
obj6.PopulateCombo(DropDownList6,query3, columnname3,datavaluefield3);
}
我的按钮点击事件抱歉我忘了添加主要内容
protected void Button1_Click(object sender, EventArgs e)
{
string query = "insert into Compliance_Tracker.dbo.tasklistManager([NATURE OF PAYMENT],[DESC],FREQUENCY,PREALERT1,PREALERT2,OWNER,[VERIFICATION OWNER],STATUS)values('" + DropDownList1.SelectedValue.ToString() + "','" + TextBox2.Text + "','" + DropDownList2.SelectedItem.Text + "','" + DropDownList3.SelectedItem.Text + "','" + DropDownList4.SelectedItem.Text + "','" + DropDownList5.SelectedItem.Text + "','" + DropDownList6.SelectedItem.Text + "','" + DropDownList7.SelectedValue + "');";
obj6.ExecuteScalar(query);
string selectquery = "select [TASK ID],[NATURE OF PAYMENT],[DESC],FREQUENCY,PREALERT1,PREALERT2,OWNER,[VERIFICATION OWNER],(case when STATUS='1' then 'Active' when STATUS='0' then 'Inactive' ELSE 'UNKNOWN' END)as STATUS,ID from Compliance_Tracker.dbo.tasklistManager;";
obj6.PopulateGrid(GridView1, selectquery);
TextBox2.Text = string.Empty;
DropDownList7.SelectedItem.Text = "Active";
}
protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e) { }
protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e) { }
protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e) { }
protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e) { }
protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e) { }
}
这是我的HTML代码
<%@ Page Title="" Language="C#" MasterPageFile="~/LoggedInMasterPage.master" AutoEventWireup="true" CodeFile="TaskList.aspx.cs" Inherits="TaskList" %>
<asp:TemplateField HeaderText="TASK ID" SortExpression="TASK ID" HeaderStyle-BackColor="DarkGreen" HeaderStyle-ForeColor="White">
<ItemTemplate>
<asp:Label ID="TASKID" runat="server" Text='<%#Eval("[TASK ID]") %>' />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="NATURE OF PAYMENT" SortExpression="NATURE OF PAYMENT" HeaderStyle-BackColor="DarkGreen" HeaderStyle-ForeColor="White">
<ItemTemplate>
<asp:Label ID="NOP" runat="server" Text='<%#Eval("[NATURE OF PAYMENT]") %>' />
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList runat="server" ID="dropdownnop"></asp:DropDownList>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="DESC" HeaderStyle-BackColor="DarkGreen" HeaderStyle-ForeColor="White">
<ItemTemplate>
<asp:Label runat="server" ID="DESC" Text='<%#Eval("[DESC]") %>'/>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID ="DESC" runat="server" Text='<%#Eval("[DESC]") %>'></asp:TextBox>
<asp:RequiredFieldValidator ID="REQUIREDFIELDVALIDATORDESC" runat="server" ControlToValidate="DESC" ErrorMessage="FIELD CANNOT BE EMPTY"></asp:RequiredFieldValidator>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="FREQUENCY" HeaderStyle-BackColor="DarkGreen" HeaderStyle-ForeColor="White">
<ItemTemplate>
<asp:Label runat="server" ID="FREQUENCY" Text='<%#Eval("FREQUENCY") %>' />
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList runat="server" ID="dropdownfreq"></asp:DropDownList>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="DUE DATE OF PAYMENT" HeaderStyle-BackColor="DarkGreen" HeaderStyle-ForeColor="White">
<ItemTemplate>
<asp:Label runat="server" ID="DDOP" Text='<%#Eval("PREALERT1") %>' />
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList runat="server" ID="dropdownddop"></asp:DropDownList>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="DUE DATE OF SUBMISSION OF RETURN" HeaderStyle-BackColor="DarkGreen" HeaderStyle-ForeColor="White">
<ItemTemplate>
<asp:Label runat="server" ID="DDOSOR" Text='<%#Eval("PREALERT2") %>' />
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList runat="server" ID="dropdownddosor"></asp:DropDownList>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="OWNER" HeaderStyle-BackColor="DarkGreen" HeaderStyle-ForeColor="White">
<ItemTemplate>
<asp:Label runat="server" ID="OWNER" Text='<%#Eval("OWNER") %>' />
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList runat="server" ID="dropdownowner"></asp:DropDownList>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="VERIFICATION OWNER" HeaderStyle-BackColor="DarkGreen" HeaderStyle-ForeColor="White">
<ItemTemplate>
<asp:Label runat="server" ID="VO" Text='<%#Eval("[VERIFICATION OWNER]") %>' />
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList runat="server" ID="dropdownvo"></asp:DropDownList>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="STATUS" HeaderStyle-BackColor="DarkGreen" HeaderStyle-ForeColor="White">
<ItemTemplate>
<asp:Label runat="server" ID="STATUS" Text='<%#Eval("STATUS") %>'/>
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList runat ="server" ID="dropdownstatus">
<asp:ListItem Text="Active" Value="1"></asp:ListItem>
<asp:ListItem Text="Inactive" Value="0"></asp:ListItem>
</asp:DropDownList>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField Visible="false" HeaderText="ID">
<ItemTemplate>
<asp:Label runat="server" ID="ID" Text='<%#Eval("ID") %>' />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Action" HeaderStyle-BackColor="DarkGreen" HeaderStyle-ForeColor="White">
<ItemTemplate>
<asp:LinkButton ID="btnEdit" Text="Edit" runat="server" CommandName="Edit" />
<asp:LinkButton ID="btnDelete" Text="Delete" runat="server" CommandName="Delete" />
</ItemTemplate>
<EditItemTemplate>
<asp:LinkButton ID="btnUpdate" Text="Update" runat="server" CommandName="Update" />
<asp:LinkButton ID="btnCancel" Text="Cancel" runat="server" CommandName="Cancel" />
</EditItemTemplate>
</asp:TemplateField>
</Columns>
<PagerSettings FirstPageText="First" LastPageText="Last" Mode="NumericFirstLast" PageButtonCount="4" />
</asp:GridView>
这是我的populatecombo代码
public bool PopulateCombo(DropDownList DDList, string strSQL, string DisMember, string ValMember)
{
SqlDataAdapter DAdpt = new SqlDataAdapter();
DataSet DSet = new DataSet();
try
{
if (Conn.State == ConnectionState.Closed)
Conn.Open();
DAdpt = new SqlDataAdapter(strSQL, Conn);
DAdpt.Fill(DSet);
DDList.DataSource = DSet.Tables[0];
DDList.DataTextField = DisMember;
DDList.DataValueField = ValMember;
DDList.DataBind();
return true;
}
catch (Exception Ex)
{
//return null;
throw new Exception(Ex.Message);
}
finally
{
DAdpt.Dispose();
DSet.Dispose();
Conn.Close();
}
}
这是我的执行标量函数
public object ExecuteScalar(string strSQL)
{
try
{
if (Conn.State == ConnectionState.Closed)
Conn.Open();
Comm = new SqlCommand(strSQL, Conn);
return Comm.ExecuteScalar();
}
catch (Exception Ex)
{
//return null;
throw new Exception(Ex.Message);
}
finally
{
Comm.Dispose();
Conn.Close();
}
}
答案 0 :(得分：2)
我认为这是Page_Load中的一个问题。您已检查if(!IsPostBack)，之后您在括号中有一些代码：
if(!IsPostBack)
{
//populate gridview
....
}
但是这个代码的其余部分在这个初始块之后是括号，因此每次回发时它都会被触发，因此重置列表。所有代码都应该在第一组大括号中，你可以删除绑定下拉列表的其他块周围的所有额外大括号：
if(!IsPostBack)
{
//populate gridview
....
// populate dropdownlist for prealert 1
...
// populate dropdown list for prealert 2
...
//populate dropdown for Nature of Payment
...
//populate dropdown for frequency
...
//populate dropdown for owner
...
//populate dropdown for owner verification
...
}
如果您在页面加载中设置断点，则应该看到在提交时，它会重新加载每个下拉列表并将其值再次设置为初始值。