转asp.net C#简单计算器

一个简单的计算器，如图：

前台代码如下：

<div>

        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>

        <asp:DropDownList ID="DropDownList1" runat="server">

            <asp:ListItem>选择</asp:ListItem>

            <asp:ListItem>+</asp:ListItem>

            <asp:ListItem>-</asp:ListItem>

            <asp:ListItem>*</asp:ListItem>

            <asp:ListItem>/</asp:ListItem>

            <asp:ListItem>%</asp:ListItem>

        </asp:DropDownList>

        <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>=<asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>

        <asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />     

    </div>

后台代码：

        
          

         
           protected
         
            
         
           void
         
            Button1_Click(
         
           object
         
            sender, EventArgs e)
 {
 
         
           double
         
            a 
         
           =
         
            Convert.ToDouble(TextBox1.Text);
 
         
           double
         
            b 
         
           =
         
            Convert.ToDouble(TextBox2.Text);
 
         
           string
         
            c 
         
           =
         
            DropDownList1.Text;
 
         
           double
         
            d 
         
           =
         
            
         
           0
         
           ;
 d 
         
           =
         
            Class1.Switch(a, b, c, d);
 TextBox3.Text 
         
           =
         
            Convert.ToString(d); 
 }
        
          

 

调用Class1类中的Switch 方法:

                  
                    

                   
                     public
                   
                      
                   
                     class
                   
                      Class1
{
 
                   
                     //
                   
                     四则运算
                   
                     

                   
                      
                   
                     public
                   
                      
                   
                     static
                   
                      
                   
                     double
                   
                      Switch(
                   
                     double
                   
                      a, 
                   
                     double
                   
                      b, 
                   
                     string
                   
                      c, 
                   
                     double
                   
                      d)
 {
 
                   
                     switch
                   
                      (c)
{
 
                   
                     case
                   
                      
                   
                     "
                   
                     +
                   
                     "
                   
                     :
 d 
                   
                     =
                   
                      a 
                   
                     +
                   
                      b;
 
                   
                     break
                   
                     ;
 
                   
                     case
                   
                      
                   
                     "
                   
                     -
                   
                     "
                   
                     :
 d 
                   
                     =
                   
                      a 
                   
                     -
                   
                      b;
 
                   
                     break
                   
                     ;
 
                   
                     case
                   
                      
                   
                     "
                   
                     *
                   
                     "
                   
                     :
 d 
                   
                     =
                   
                      a 
                   
                     *
                   
                      b;
 
                   
                     break
                   
                     ;
 
                   
                     case
                   
                      
                   
                     "
                   
                     /
                   
                     "
                   
                     :
 d 
                   
                     =
                   
                      a 
                   
                     /
                   
                      b;
 
                   
                     break
                   
                     ;
 
                   
                     case
                   
                      
                   
                     "
                   
                     %
                   
                     "
                   
                     :
 d 
                   
                     =
                   
                      a 
                   
                     %
                   
                      b;
 
                   
                     break
                   
                     ;
 
                   
                     default
                   
                     :
 
                   
                     break
                   
                     ;
 }
 
                   
                     return
                   
                      d;
 }
}