Asp.net 如何选中复选框列表中的选定项(由代码生成)
我有一个ASP.NET/VB应用程序 我需要选中复选框列表中的选定项,但复选框是从代码隐藏动态生成的Asp.net 如何选中复选框列表中的选定项(由代码生成),asp.net,vb.net,checkboxlist,Asp.net,Vb.net,Checkboxlist,我有一个ASP.NET/VB应用程序 我需要选中复选框列表中的选定项,但复选框是从代码隐藏动态生成的 <asp:Panel ID="panel1" runat="server"> <asp:Button ID="Button1" runat="server" Text="Save" /> <asp:Label ID="lbl_Selected_Items" runat="server" Text=""></asp:Label> &l
<asp:Panel ID="panel1" runat="server">
<asp:Button ID="Button1" runat="server" Text="Save" />
<asp:Label ID="lbl_Selected_Items" runat="server" Text=""></asp:Label>
</asp:Panel>
按钮1单击事件
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim CheckBoxList1 As CheckBoxList = CType(Me.FindControl("CheckBoxList"), CheckBoxList)
Dim sCheckedValue As String = ""
For Each oItem As ListItem In CheckBoxList1.Items
If oItem.Selected Then
If sCheckedValue = "" Then
sCheckedValue = ("Selected Value : " + oItem.Value & " Selected Text: ") + oItem.Text
Else
sCheckedValue += ("<br/>Selected Value : " + oItem.Value & " Selected Text: ") + oItem.Text
End If
End If
Next
lbl_Selected_Items.Text = sCheckedValue
Protected Sub Button1\u Click(ByVal sender作为对象,ByVal e作为System.EventArgs)处理按钮1。单击
Dim CheckBoxList1作为CheckBoxList=CType(Me.FindControl(“CheckBoxList”),CheckBoxList)
Dim sCheckedValue As String=“”
对于CheckBoxList1.Items中的每个oItem作为ListItem
如果选择了oItem,则
如果sCheckedValue=“”,则
sCheckedValue=(“选定值:”+oItem.Value&“选定文本:”)+oItem.Text
其他的
sCheckedValue+=(“
所选值:”+oItem.Value&“所选文本:”)+oItem.Text
如果结束
如果结束
下一个
lbl_Selected_Items.Text=sCheckedValue
错误文本:空引用异常对象引用未设置为对象的实例-
那么发生了什么?错误?没有结果 此时,我唯一可以推荐的是在pageinit中加载动态控件,而不是在pageload中加载 编辑 调试时,您会发现按钮单击第一行上的复选框为空。代码中有两个错误
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim CheckBoxList1 As CheckBoxList = CType(pagerview.FindControl("cbl1"), CheckBoxList)
Dim sCheckedValue As String = ""
For Each oItem As ListItem In CheckBoxList1.Items
If oItem.Selected Then
If sCheckedValue = "" Then
sCheckedValue = ("Selected Value : " + oItem.Value & " Selected Text: ") + oItem.Text
Else
sCheckedValue += ("<br/>Selected Value : " + oItem.Value & " Selected Text: ") + oItem.Text
End If
End If
Next
lbl_Selected_Items.Text = sCheckedValue
End Sub
Protected Sub Button1\u Click(ByVal sender作为对象,ByVal e作为System.EventArgs)处理按钮1。单击
Dim CheckBoxList1作为CheckBoxList=CType(pagerview.FindControl(“cbl1”),CheckBoxList)
Dim sCheckedValue As String=“”
对于CheckBoxList1.Items中的每个oItem作为ListItem
如果选择了oItem,则
如果sCheckedValue=“”,则
sCheckedValue=(“选定值:”+oItem.Value&“选定文本:”)+oItem.Text
其他的
sCheckedValue+=(“
所选值:”+oItem.Value&“所选文本:”)+oItem.Text
如果结束
如果结束
下一个
lbl_Selected_Items.Text=sCheckedValue
端接头
谢谢,错误为空引用异常对象引用未设置为object@MrSmith这样的事情必须出现在评论中,而不是答案中!答案是确切的或可能的解决方案,而您的问题或建议是comment@Khazratbek谢谢你说清楚。但是否决票,你今天过得不好吗,伙计?享受答案。@Ibrahim Alsurkhi这解决了你的问题吗?如果是的话,你能标出答案吗?
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
Handles Me.Load
Dim CheckBoxList As New CheckBoxList
CheckBoxList.ID = "cbl1"
pagerview.Controls.Add(CheckBoxList)
End Sub
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim CheckBoxList1 As CheckBoxList = CType(pagerview.FindControl("cbl1"), CheckBoxList)
Dim sCheckedValue As String = ""
For Each oItem As ListItem In CheckBoxList1.Items
If oItem.Selected Then
If sCheckedValue = "" Then
sCheckedValue = ("Selected Value : " + oItem.Value & " Selected Text: ") + oItem.Text
Else
sCheckedValue += ("<br/>Selected Value : " + oItem.Value & " Selected Text: ") + oItem.Text
End If
End If
Next
lbl_Selected_Items.Text = sCheckedValue
End Sub