UC知道DropDownList未将对象引用设置到对象的实例
来源：百度知道 编辑：UC知道 时间：2024/05/31 16:14:15
.aspx内容
<form id="form1" runat="server">
<div>
<%
for (int i = 0; i < 2; i++)
{
DropDownList1.Items.Add(i.ToString());
}
%>
<asp:DropDownList ID="DropDownList1" runat="server">
</asp:DropDownList>
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button" />
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label></div>
</form>
.cs内容
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
Label1.Text =DropDownList1.SelectedItem.Text;
}
为什么会出现"未将对象引用设置到对象的实例"的错误
该怎么解决???
<form id="form1" runat="server">
<div>
<%
for (int i = 0; i < 2; i++)
{
DropDownList1.Items.Add(i.ToString());
}
%>
<asp:DropDownList ID="DropDownList1" runat="server">
</asp:DropDownList>
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button" />
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label></div>
</form>
.cs内容
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
Label1.Text =DropDownList1.SelectedItem.Text;
}
为什么会出现"未将对象引用设置到对象的实例"的错误
该怎么解决???
Label1.Text =DropDownList1.SelectedItem.Text; 是这句吗？如果是可能是因为你DropDownList1里面没填进东西，你可以跟踪一下啊你设置DropDownList1.SelectedIndex=0;看下还报错不？
<asp:DropDownList ID="DropDownList1" runat="server">
<%
for (int i = 0; i < 2; i++)
{
%>
<asp:ListItem><%i%></asp:ListItem>
<%
}
%>
</asp:DropDownList>
看看这样行不行啊?