我有一個 ASP.NET HTML 網站，我想在其中使用下拉選單更新我的 SQLDataSource SELECT 命令。用戶可以選擇按日期、持續時間或播放器排序，GridView 將更新顯示來自我的 mdf 資料庫的新排序結果。我真的不知道如何解決這個問題，因為我對 ASP.NET 還很陌生。我可以只做一些關于如何去做的指標，以及使用什么方法。我可以谷歌教程，問題是知道谷歌什么。非常感謝任何建議:) 我的代碼：
<form id="form1" runat="server">
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="RunsData">
<Columns>
<asp:BoundField DataField="PlayerId" HeaderText="PlayerId" SortExpression="PlayerId" />
<asp:BoundField DataField="Duration" HeaderText="Duration" SortExpression="Duration" />
<asp:BoundField DataField="VersionId" HeaderText="VersionId" SortExpression="VersionId" />
<asp:BoundField DataField="DateUploaded" HeaderText="DateUploaded" SortExpression="DateUploaded" />
</Columns>
</asp:GridView>
<asp:SqlDataSource ID="RunsData" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>" SelectCommand="SELECT [PlayerId], [Duration], [VersionId], [DateUploaded] FROM [Run] ORDER BY [Duration]"></asp:SqlDataSource>
</form>
<div>
<label class="label" for="version">Version: </label>
<select name="version" id="version">
<option value="lev1">Level 1</option>
<option value="lev1to3">Level 1-3</option>
<option value="lev8">Level 8</option>
<option value="lev17">Level 17</option>
</select>
<label class="label" for="sortby">Sort By: </label>
<select name="sortby" id="sortby">
<option value="duration">Duration</option>
<option value="date">Date</option>
<option value="player">Player</option>
</select>
</div>
</div>
uj5u.com熱心網友回復：
好的，首先，我認為將過濾器放在網格頂部（上方）而不是下方更好？（只是一個想法）。
事實上，更好的主意是將兩個組合框直接放入網格標題中 - 更好！
但是，讓我們一步一步來。
首先，我建議我們轉儲（洗掉）網頁中的資料源。可以很方便，向導生成它們 - 非常感謝 - 一切都很好。然而，即使我經常使用向導來創建 GV，我也會炸掉資料源，并使用代碼。什么時候使用代碼來填充 GV 是一個好主意？
為什么當然要過濾它！！！
所以，讓我們這樣做：
洗掉/移除 Sqldata 源 - 我們不會使用它。
從 GV 中洗掉它 - DataSourceID="RunsData"
此外，您清楚地使用向導來創建和設定該 GV，但現在使用選擇 html？為什么不使用下拉串列？向導不僅可以為您構建它們（就像 GV，它們還有豐富的 .net 事件模型。您可以像 GV 一樣推動、驅動下拉串列（它們是資料源友好的）。
所以，我們現在假設這個標記：
<div style="float:left">
<label class="label" for="version">Version: </label>
<asp:DropDownList ID="cboVersion" runat="server" Width="150px">
<asp:ListItem></asp:ListItem>
<asp:ListItem Value="1">Level 1</asp:ListItem>
<asp:ListItem Value="1-3">Level 1-3</asp:ListItem>
<asp:ListItem Value="8">Level 8</asp:ListItem>
<asp:ListItem Value="17">Level 17</asp:ListItem>
</asp:DropDownList>
</div>
<div style="float:left;padding-left:25px">
<label class="label" for="sortby">Sort By:</label>
<asp:DropDownList ID="cboSortBy" runat="server" Width="150px">
<asp:ListItem></asp:ListItem>
<asp:ListItem Value="duration">Duration</asp:ListItem>
<asp:ListItem Value="DateUploaded">Date</asp:ListItem>
<asp:ListItem>Player</asp:ListItem>
</asp:DropDownList>
</div>
<div style="clear:both;height:10px"></div> <%-- Start new line for grid --%>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="RunsData">
<Columns>
<asp:BoundField DataField="PlayerId" HeaderText="PlayerId" />
<asp:BoundField DataField="Duration" HeaderText="Duration" />
<asp:BoundField DataField="VersionId" HeaderText="VersionId" />
<asp:BoundField DataField="DateUploaded" HeaderText="DateUploaded" />
</Columns>
</asp:GridView>
</form>
所以，請注意，就像 GV 下拉串列作為編輯專案選項，像這樣：
然后你會得到這個：
另外，當您想要級別時說 1-3 該列是數字型別嗎？
And as noted, I put the filters tat the top of the grid. Since your placing the filers below the grid? You have to explain that goal - not seen filters on the bottom of a grid in about 20 years now - maybe some desktop apps? But SUPER rare. Since that choice is SUPER RARE? Then you may well have a good reason, but I placed the filter at the top. In fact, we would/could consider placing the dropdowns in the header of the GV (and that is allowed!!!). But, hey, one step at a time.
I also don't grasp, see the need for two forms on the page? (again, might be a reason, but you better have one heck of a good and great reason for that choice).
So, we now have this:
<div style="float:left">
<label class="label" for="version">Version: </label>
<asp:DropDownList ID="cboVersion" runat="server" Width="150px" AutoPostBack="true">
<asp:ListItem></asp:ListItem>
<asp:ListItem Value="1">Level 1</asp:ListItem>
<asp:ListItem Value="1,3">Level 1-3</asp:ListItem>
<asp:ListItem Value="8">Level 8</asp:ListItem>
<asp:ListItem Value="17">Level 17</asp:ListItem>
</asp:DropDownList>
</div>
<div style="float:left;padding-left:25px">
<label class="label" for="sortby">Sort By:</label>
<asp:DropDownList ID="cboSortBy" runat="server" Width="150px" AutoPostBack="true" >
<asp:ListItem></asp:ListItem>
<asp:ListItem Value="duration">Duration</asp:ListItem>
<asp:ListItem Value="DateUploaded">Date</asp:ListItem>
<asp:ListItem>Player</asp:ListItem>
</asp:DropDownList>
</div>
<div style="clear:both;height:10px"></div> <%-- Start new line for grid --%>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
Width="30%" CssClass="table">
<Columns>
<asp:BoundField DataField="PlayerId" HeaderText="PlayerId" />
<asp:BoundField DataField="Duration" HeaderText="Duration" />
<asp:BoundField DataField="VersionId" HeaderText="VersionId" />
<asp:BoundField DataField="DateUploaded" HeaderText="DateUploaded" />
</Columns>
</asp:GridView>
Note careful we added/allow/have a BLANK choice for the two combo boxes.
Ok, so now our code to load up the grid like this:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
loadgrid()
End If
End Sub
Sub loadgrid()
Using conn As New SqlConnection(My.Settings.TEST4)
Using cmdSQL As New SqlCommand("SELECT PlayerId, Duration, VersionId, DateUploaded FROM [Run]", conn)
' add filter
Dim strWhere As String = ""
If cboVersion.Text <> "" Then
If InStr(cboVersion.SelectedItem.Value, "-") = 0 Then
' one value
cmdSQL.CommandText &= " WHERE VersionID = @id"
cmdSQL.Parameters.Add("@id", SqlDbType.Int).Value = cboVersion.SelectedItem.Value
Else
' we have range
Dim MyRnage() As String = Split(cboVersion.SelectedItem.Value, "-")
cmdSQL.CommandText &= " WHERE VersionID is between @lower and @upper"
cmdSQL.Parameters.Add("@lower", SqlDbType.Int).Value = MyRnage(0)
cmdSQL.Parameters.Add("@upper", SqlDbType.Int).Value = MyRnage(1)
End If
End If
' add order by
If cboSortBy.Text = "" Then
cmdSQL.CommandText &= " ORDER BY Duration"
Else
cmdSQL.CommandText &= " ORDER BY " & cboSortBy.SelectedItem.Value
End If
Dim rstData As New DataTable
conn.Open
rstData.Load(cmdSQL.ExecuteReader)
GridView1.DataSource = rstData
GridView1.DataBind()
End Using
End Using
End Sub
Since we have auto post-back, then for both the sort by combo, filter by, then we have two event stubs here.
Protected Sub cboVersion_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cboVersion.SelectedIndexChanged
loadgrid()
End Sub
Protected Sub cboSortBy_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cboSortBy.SelectedIndexChanged
loadgrid()
End Sub
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