WPF设计简单计算器

本文中设计的计算器仅支持单次双目运算，可连续计算。

实验要求、
1、在wpf项目中编程实现一个简单计算器，具体要求如下：
1）实现+，-，*，/运算
2）可以连续进行计算。
效果如图：

*该程序中数字通过点击对应按钮输入，运算符包含四种常用运算，除此之外还有退格以及清空操作，输入以及运算结果在上方文本框内显示

1.首先，该程序中只涉及单次运算，所以我们可以在隐藏文件里声明两个全局变量来相应的保存operation前后两个数（字符串）。

 		string num1 = null;   //运算符之前的数
        string num2 = null;   //运算符之后的数
        string ope = null;    //运算符

2.每次键入一个位数要判断放在num1里还是num2里。

private void button1_Click(object sender, RoutedEventArgs e)
        { 
            if (ope == null)
            { 
                num1 += button1.Content;
                textBox.Text = num1;
            }
            else
            { 
                num2 += button1.Content;
                textBox.Text = num2;
            }
        }

3.键入运算符是对变量ope赋值(因为是单次计算，所以运算符没必要在文本框里显示)

 private void buttonADD_Click(object sender, RoutedEventArgs e)
        { 
            ope = "+";
        }

4.CE清空操作，将textbox中的内容以及所有变量清空

 private void buttonCE_Click(object sender, RoutedEventArgs e)
        { 
            //if (ope == null)
            //{ 
            // num1 = textBox.Text;
            //}
            //else
            //{ 
            // num2 = textBox.Text;
            //}
            this.textBox.Text = "";
            num1 = null;
            num2 = null;
            ope = null;
        }

5.退格操作

 private void buttonBK_Click(object sender, RoutedEventArgs e)
        { 
            string s = textBox.Text;
            int len = s.Length;
            if (textBox.Text != null && len >= 1)
                textBox.Text = s.Remove(len - 1);
            if (ope == null)
            { 
                num1 = textBox.Text;
            }
            else
            { 
                num2 = textBox.Text;
            }
        }

6.计算结果（利用switch case ）

private void buttonEQ_Click(object sender, RoutedEventArgs e)
        { 
            switch (ope)
            { 
                case "+":
                    textBox.Text = Convert.ToString(Convert.ToDouble(num1) + Convert.ToDouble(num2));
                    break;
                case "-":
                    textBox.Text = Convert.ToString(Convert.ToDouble(num1) - Convert.ToDouble(num2));
                    break;
                case "*":
                    textBox.Text = Convert.ToString(Convert.ToDouble(num1) * Convert.ToDouble(num2));
                    break;
                case "/":
                    textBox.Text = Convert.ToString(Convert.ToDouble(num1) / Convert.ToDouble(num2));
                    break;
            }
            num1 = textBox.Text;   
            num2 = null;
            ope = null;
        }

将结果值赋给num1来实现连续计算.

效果如如下：

完整代码如下：
*xaml

Window x:Class="小小计算器.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="计算器" Height="382" Width="362">
    <Grid Height="335">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="48*" />
            <ColumnDefinition Width="23*" />
        </Grid.ColumnDefinitions>
        <Button Content="CE" Height="30" HorizontalAlignment="Left" Margin="62,87,0,0" Name="buttonCE" VerticalAlignment="Top" Width="41" Click="buttonCE_Click" />
        <Button Content="＜-" Height="29" HorizontalAlignment="Left" Margin="118,87,0,0" Name="buttonBK" VerticalAlignment="Top" Width="45" Click="buttonBK_Click" />
        <Button Content="." Height="29" HorizontalAlignment="Left" Margin="185,87,0,0" Name="buttonDOT" VerticalAlignment="Top" Width="46" Click="buttonDOT_Click" />
        <Button Content="+" Height="28" HorizontalAlignment="Left" Margin="7,87,0,0" Name="buttonADD" VerticalAlignment="Top" Width="47" Click="buttonADD_Click" Grid.Column="1" />
        <Button Content="1" Height="30" HorizontalAlignment="Left" Margin="62,136,0,0" Name="button1" VerticalAlignment="Top" Width="41" Click="button1_Click" />
        <Button Content="2" Height="30" HorizontalAlignment="Left" Margin="118,136,0,0" Name="button2" VerticalAlignment="Top" Width="45" Click="button2_Click" />
        <Button Content="3" Height="30" HorizontalAlignment="Left" Margin="185,136,0,0" Name="button3" VerticalAlignment="Top" Width="46" Click="button3_Click" RenderTransformOrigin="1.217,0.437" />
        <Button Content="-" Height="30" HorizontalAlignment="Left" Margin="7,136,0,0" Name="buttonSUB" VerticalAlignment="Top" Width="47" Click="buttonSUB_Click" Grid.Column="1" />
        <Button Content="4" Height="30" HorizontalAlignment="Left" Margin="62,186,0,0" Name="button4" VerticalAlignment="Top" Width="41" Click="button4_Click" />
        <Button Content="5" Height="30" HorizontalAlignment="Left" Margin="118,186,0,0" Name="button5" VerticalAlignment="Top" Width="45" Click="button5_Click" />
        <Button Content="6" Height="30" HorizontalAlignment="Left" Margin="185,186,0,0" Name="button6" VerticalAlignment="Top" Width="46" Click="button6_Click" />
        <Button Content="*" Height="30" HorizontalAlignment="Left" Margin="7,186,0,0" Name="buttonMUP" VerticalAlignment="Top" Width="47" Click="buttonMUP_Click" Grid.Column="1" />
        <Button Content="7" Height="30" HorizontalAlignment="Left" Margin="62,231,0,0" Name="button7" VerticalAlignment="Top" Width="40" Click="button7_Click" />
        <Button Content="8" Height="30" HorizontalAlignment="Left" Margin="118,231,0,0" Name="button8" VerticalAlignment="Top" Width="45" Click="button8_Click" />
        <Button Content="9" Height="30" HorizontalAlignment="Left" Margin="185,231,0,0" Name="button9" VerticalAlignment="Top" Width="46" Click="button9_Click" />
        <Button Content="/" Height="30" HorizontalAlignment="Left" Margin="7,231,0,0" Name="buttonDIV" VerticalAlignment="Top" Width="47" Click="buttonDIV_Click" Grid.Column="1" />
        <Button Content="0" Height="25" HorizontalAlignment="Left" Margin="62,281,0,0" Name="button0" VerticalAlignment="Top" Width="101" Click="button0_Click" />
        <Button Content="=" Height="25" HorizontalAlignment="Right" Margin="0,281,59.2,0" Name="buttonEQ" VerticalAlignment="Top" Width="111" Grid.ColumnSpan="2" Click="buttonEQ_Click" RenderTransformOrigin="-0.085,0.493" />
        <TextBox Grid.ColumnSpan="2" Height="32" HorizontalAlignment="Left" Margin="88,30,0,0" Name="textBox" VerticalAlignment="Top" Width="173" />
    </Grid>
</Window>

.cs文件

namespace 小小计算器
{ 
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    { 
        string num1 = null;   //运算符之前的数
        string num2 = null;   //运算符之后的数
        string ope = null;    //运算符
        public MainWindow()
        { 
            InitializeComponent();
        }

        private void button1_Click(object sender, RoutedEventArgs e)
        { 
            if (ope == null)
            { 
                num1 += button1.Content;
                textBox.Text = num1;
            }
            else
            { 
                num2 += button1.Content;
                textBox.Text = num2;
            }
        }

        private void button2_Click(object sender, RoutedEventArgs e)
        { 
            if (ope == null)
            { 
                num1 += button2.Content;
                textBox.Text = num1;
            }
            else
            { 
                num2 += button2.Content;
                textBox.Text = num2;
            }
        }

        private void button3_Click(object sender, RoutedEventArgs e)
        { 
            if (ope == null)
            { 
                num1 += button3.Content;
                textBox.Text = num1;
            }
            else
            { 
                num2 += button3.Content;
                textBox.Text = num2;
            }
        }

        private void button4_Click(object sender, RoutedEventArgs e)
        { 
            if (ope == null)
            { 
                num1 += button4.Content;
                textBox.Text = num1;
            }
            else
            { 
                num2 += button4.Content;
                textBox.Text = num2;
            }
        }

        private void button5_Click(object sender, RoutedEventArgs e)
        { 
            if (ope == null)
            { 
                num1 += button5.Content;
                textBox.Text = num1;
            }
            else
            { 
                num2 += button5.Content;
                textBox.Text = num2;
            }
        }

        private void button6_Click(object sender, RoutedEventArgs e)
        { 
            if (ope == null)
            { 
                num1 += button6.Content;
                textBox.Text = num1;
            }
            else
            { 
                num2 += button6.Content;
                textBox.Text = num2;
            }
        }

        private void button7_Click(object sender, RoutedEventArgs e)
        { 
            if (ope == null)
            { 
                num1 += button7.Content;
                textBox.Text = num1;
            }
            else
            { 
                num2 += button7.Content;
                textBox.Text = num2;
            }
        }

        private void button8_Click(object sender, RoutedEventArgs e)
        { 
            if (ope == null)
            { 
                num1 += button8.Content;
                textBox.Text = num1;
            }
            else
            { 
                num2 += button8.Content;
                textBox.Text = num2;
            }
        }

        private void button9_Click(object sender, RoutedEventArgs e)
        { 
            if (ope == null)
            { 
                num1 += button9.Content;
                textBox.Text = num1;
            }
            else
            { 
                num2 += button9.Content;
                textBox.Text = num2;
            }
        }
        private void button0_Click(object sender, RoutedEventArgs e)
        { 
            if (ope == null)
            { 
                num1 += button0.Content;
                textBox.Text = num1;
            }
            else
            { 
                num2 += button0.Content;
                textBox.Text = num2;
            }
        }

        private void buttonADD_Click(object sender, RoutedEventArgs e)
        { 
            ope = "+";
        }

        private void buttonSUB_Click(object sender, RoutedEventArgs e)
        { 
            ope = "-";
        }

        private void buttonMUP_Click(object sender, RoutedEventArgs e)
        { 
            ope = "*";
        }

        private void buttonDIV_Click(object sender, RoutedEventArgs e)
        { 
            ope = "/";
        }

        private void buttonDOT_Click(object sender, RoutedEventArgs e)
        { 

            if (ope == null &&!num1.Contains("."))   //如果num中已有小数点，则不允许再输入.
            { 

                num1 += buttonDOT.Content;
                textBox.Text = num1;

            }
            if(ope!=null&&!num2.Contains("."))                                  
            { 
                num2 += buttonDOT.Content;
                textBox.Text = num2;
            }
        }

        private void buttonCE_Click(object sender, RoutedEventArgs e)
        { 
            //if (ope == null)
            //{ 
            // num1 = textBox.Text;
            //}
            //else
            //{ 
            // num2 = textBox.Text;
            //}
            this.textBox.Text = "";
            num1 = null;
            num2 = null;
            ope = null;
        }

        private void buttonBK_Click(object sender, RoutedEventArgs e)
        { 
            string s = textBox.Text;
            int len = s.Length;
            if (textBox.Text != null && len >= 1)
                textBox.Text = s.Remove(len - 1);
            if (ope == null)
            { 
                num1 = textBox.Text;
            }
            else
            { 
                num2 = textBox.Text;
            }
        }

        private void buttonEQ_Click(object sender, RoutedEventArgs e)
        { 
            switch (ope)
            { 
                case "+":
                    textBox.Text = Convert.ToString(Convert.ToDouble(num1) + Convert.ToDouble(num2));
                    break;
                case "-":
                    textBox.Text = Convert.ToString(Convert.ToDouble(num1) - Convert.ToDouble(num2));
                    break;
                case "*":
                    textBox.Text = Convert.ToString(Convert.ToDouble(num1) * Convert.ToDouble(num2));
                    break;
                case "/":
                    textBox.Text = Convert.ToString(Convert.ToDouble(num1) / Convert.ToDouble(num2));
                    break;
            }
            num1 = textBox.Text;
            num2 = null;
            ope = null;
        }


    }
}