使用WPF编写一个多运算符表达式计算器

发布时间：2020-11-09 15:01:29 作者：Leah
来源：亿速云阅读：209

使用WPF编写一个多运算符表达式计算器？很多新手对此不是很清楚，为了帮助大家解决这个难题，下面小编将为大家详细讲解，有这方面需求的人可以来学习下，希望你能有所收获。

WPF实现一个简单的多运算符表达式计算器

1.先看下效果图在这里插入图片描述

首先外围给了一个grid 把他分成了两行第一行用来显示文本框给了一个低于第二行的高度第二行用来存按钮窗体的大小自己去调就好了我这里给的是380x268

<Grid.RowDefinitions>
   <RowDefinition Height="0.7*"></RowDefinition>
   <RowDefinition></RowDefinition>
</Grid.RowDefinitions>

这是一个非常简单的布局没有用到样式头部是用了一个Border给一个圆弧实现的代码如下

<Border Margin="5" Padding="5" Background="White" BorderBrush="Black" BorderThickness="3,5,3,5" CornerRadius="10" VerticalAlignment="Top" Height="130" Width="240">
      <TextBlock Name="ShowNumText" Height="100" Width="auto" VerticalAlignment="Top" FontSize="50" HorizontalAlignment="Right" >
        
      </TextBlock>
</Border>

接下来就是按键部分了用了一个UniformGrid布局类似于一个表格给4行4列最后再往里面添加按钮实现的分别给每个按钮设置背景颜色，字体颜色以及单击事件（一共4类单击事件分别是数字的、运算符的、等于号、还有一个清空C）

<UniformGrid Grid.Row="1" Rows="4" Columns="4" Height="200" Width="250">
      <Button Name="btn1" Content="1" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btn2" Content="2" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btn3" Content="3" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btnD" Content="÷" FontSize="35" Background="Black" Foreground="White" Click="btnD_Click"/>
      <Button Name="btn4" Content="4" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btn5" Content="5" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btn6" Content="6" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btnX" Content="X" FontSize="35" Background="Black" Foreground="White" Click="btnD_Click"/>
      <Button Name="btn7" Content="7" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btn8" Content="8" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btn9" Content="9" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btnM" Content="-" FontSize="35" Background="Black" Foreground="White" Click="btnD_Click"/>
      <Button Name="btnC" Content="C" FontSize="35" Background="Black" Foreground="White" Click="btnC_Click"/>
      <Button Name="btn0" Content="0" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btnE" Content="+" FontSize="35" Background="Black" Foreground="White" Click="btnD_Click"/>
      <Button Name="btnP" Content="=" FontSize="35" Background="Black" Foreground="White" Click="btnP_Click"/>
</UniformGrid>

这样我们的xaml样式就写完了，接下来就是后端了

上面的代码我们看到我们已经定义了单击事件首先找到数字的单击事件写上以下代码

var v = sender as Button;
      switch (v.Content.ToString())
      {
        case "1":
          ShowNumText.Text += 1;
          break;
        case "2":
          ShowNumText.Text += 2;
          break;
        case "3":
          ShowNumText.Text += 3;
          break;
        case "4":
          ShowNumText.Text += 4;
          break;
        case "5":
          ShowNumText.Text += 5;
          break;
        case "6":
          ShowNumText.Text += 6;
          break;
        case "7":
          ShowNumText.Text += 7;
          break;
        case "8":
          ShowNumText.Text += 8;
          break;
        case "9":
          ShowNumText.Text += 9;
          break;
        case "0":
          ShowNumText.Text += 0;
          break;

意思就是判断一下用户点击的是哪一个数字然后把他加到文本框内

接下来就是运算符的单击事件同理数字的

if (ShowNumText.Text == "")
        return;
      var v1 = sender as Button;
      switch (v1.Content.ToString())
      {
        case "+":
          ShowNumText.Text += "+";
          break;
        case "-":
          ShowNumText.Text += "-";
          break;
        case "X":
          ShowNumText.Text += "X";
          break;
        case "÷":
          ShowNumText.Text += "÷";
          break;
}

然后导入命名空间

using System.Data;

这个命名空间里面有一个超级好用的方法Compute
Compute的意思简单来说就是放入一个string类型的带有表达式的字符串计算，
找到等于号的事件加入代码

try
    {
        string str= ShowNumText.Text.Replace('X', '*');
        str= str.Replace('÷', '/');
        DataTable dt = new DataTable();
        string v = dt.Compute(str, null).ToString();
        ShowNumText.Text = v.ToString();
      }
      catch { ShowNumText.Text = ""; }

用Replace方法过滤掉 x和÷
因为Compute 是不接收数学的乘和除的

最后在清空事件里加入一个ShowNumText.Text = "";//清空文本框
这样我们的计算器就写完了！！！

前台xaml

<Window x:Class="WpfApplication1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:local="clr-namespace:WpfApplication1"
    mc:Ignorable="d"
    Title="计算机" Height="380" Width="268">
  <Grid>
    <Grid.RowDefinitions>
      <RowDefinition Height="0.7*"></RowDefinition>
      <RowDefinition></RowDefinition>
    </Grid.RowDefinitions>
    <Border Margin="5" Padding="5" Background="White" BorderBrush="Black" BorderThickness="3,5,3,5" CornerRadius="10" VerticalAlignment="Top" Height="130" Width="240">
      <TextBlock Name="ShowNumText" Height="100" Width="auto" VerticalAlignment="Top" FontSize="50" HorizontalAlignment="Right" >
        
      </TextBlock>
    </Border>
    <UniformGrid Grid.Row="1" Rows="4" Columns="4" Height="200" Width="250">
      <Button Name="btn1" Content="1" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btn2" Content="2" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btn3" Content="3" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btnD" Content="÷" FontSize="35" Background="Black" Foreground="White" Click="btnD_Click"/>
      <Button Name="btn4" Content="4" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btn5" Content="5" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btn6" Content="6" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btnX" Content="X" FontSize="35" Background="Black" Foreground="White" Click="btnD_Click"/>
      <Button Name="btn7" Content="7" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btn8" Content="8" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btn9" Content="9" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btnM" Content="-" FontSize="35" Background="Black" Foreground="White" Click="btnD_Click"/>
      <Button Name="btnC" Content="C" FontSize="35" Background="Black" Foreground="White" Click="btnC_Click"/>
      <Button Name="btn0" Content="0" FontSize="35" Background="Black" Foreground="White" Click="btn1_Click_1"/>
      <Button Name="btnE" Content="+" FontSize="35" Background="Black" Foreground="White" Click="btnD_Click"/>
      <Button Name="btnP" Content="=" FontSize="35" Background="Black" Foreground="White" Click="btnP_Click"/>
    </UniformGrid>
  </Grid>
</Window>

后台代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Data;
namespace WpfApplication1
{
  /// <summary>
  /// MainWindow.xaml 的交互逻辑
  /// </summary>
  public partial class MainWindow : Window
  {
    public MainWindow()
    {
      InitializeComponent();
      
    }
    private void btn1_Click_1(object sender, RoutedEventArgs e)//0-9绑定同一个事件
    { 
      var v = sender as Button;
      switch (v.Content.ToString())
      {
        case "1":
          ShowNumText.Text += 1;
          break;
        case "2":
          ShowNumText.Text += 2;
          break;
        case "3":
          ShowNumText.Text += 3;
          break;
        case "4":
          ShowNumText.Text += 4;
          break;
        case "5":
          ShowNumText.Text += 5;
          break;
        case "6":
          ShowNumText.Text += 6;
          break;
        case "7":
          ShowNumText.Text += 7;
          break;
        case "8":
          ShowNumText.Text += 8;
          break;
        case "9":
          ShowNumText.Text += 9;
          break;
        case "0":
          ShowNumText.Text += 0;
          break;
      } 
    }
    private void btnD_Click(object sender, RoutedEventArgs e)//运算符也绑定同一个事件
    {
      if (ShowNumText.Text == "")
        return;
      var v1 = sender as Button;
      switch (v1.Content.ToString())
      {
        case "+":
          ShowNumText.Text += "+";
          break;
        case "-":
          ShowNumText.Text += "-";
          break;
        case "X":
          ShowNumText.Text += "X";
          break;
        case "÷":
          ShowNumText.Text += "÷";
          break;
      }  
    }
    private void btnP_Click(object sender, RoutedEventArgs e)
    {
      try
      {
        string str= ShowNumText.Text.Replace('X', '*');
        str= str.Replace('÷', '/');
        DataTable dt = new DataTable();
        string v = dt.Compute(str, null).ToString();
        ShowNumText.Text = v.ToString();
      }
      catch { ShowNumText.Text = ""; }
    }
    private void btnC_Click(object sender, RoutedEventArgs e)
    {
      ShowNumText.Text = "";//清空文本框
    }
  }
}

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使用WPF编写一个多运算符表达式计算器

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