Question

asp.net怎么用控件实现加减乘除

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Answer 1

新建aspx页面：代码如下：

<div>
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
        <asp:DropDownList ID="DropDownList1" runat="server">
        <asp:ListItem Text="+" Value="+"></asp:ListItem>
        <asp:ListItem Text="-" Value="-"></asp:ListItem>
        <asp:ListItem Text="*" Value="*"></asp:ListItem>
        <asp:ListItem Text="/" Value="/"></asp:ListItem>
        </asp:DropDownList>
        <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
        <asp:Button ID="Button1" runat="server" Text="计算值" onclick="Button1_Click" />
        <asp:Label ID="Label1" runat="server" Text=""></asp:Label>
    </div>

在Button1的单击事件下写后台代码：

protected void Button1_Click(object sender, EventArgs e)
        {
            string value = "";
            float numA = Convert.ToSingle(TextBox1.Text);
            float numB = Convert.ToSingle(TextBox2.Text);
            switch (DropDownList1.SelectedValue)
            {
                case "+":
                    value = (numA+numB).ToString();
                    break;
                case "-":
                    value = (numA - numB).ToString();
                    break;
                case "*":
                    value = (numA * numB).ToString();
                    break;
                case "/":
                    value = (numA / numB).ToString();
                    break;
            }
            Label1.Text = TextBox1.Text + DropDownList1.SelectedValue + TextBox2.Text + "=" + value;
        }

运行效果如下：