C#——《C#語言程序設計》實驗報告——Windows桌面編程

一、實驗目的

1. 熟悉使用WPF進行界面編程的基本過程；
2. 掌握WPF佈局、控件、事件的使用。

二、實驗內容

1. 使用WPF技術，進行合理佈局，設計一個窗體應用程序，完成一些常用度量單位的轉換，基本模板如下圖：

 

對於本實驗，屬於一個小型的界面，主要設計過程包括：

（1）新建WPF工程。

（2）選擇內容佈局控件。以Grid控件爲主，在其中內嵌其它佈局控件。併爲佈局控件設置一些重要的屬性，如行數與列數，平均分配還是比例分配等。操作方式，主要通過拖放控件，再輔以少量XAML編輯。

（3）選擇各類控件，爲它們安排好位置，設置它們的各類屬性，如顏色、大小、靠左還是靠右、margin、padding等。首先拖放控件，然後在屬性窗口中編輯。

（4）添加事件處理方法。通過事件標籤頁或雙擊控件添加。

另外要求：

1. 在原始數據和換算結果後加兩個TextBlock，綁定到原始單位和換算單位。
2. 當在TextBox輸入內容時，換算結果內容清空。
3. 如果原始數據格式有誤，要提示用戶。
4. 可在顏色、佈局、功能等方面按自己的想法進行完善。

   其中：

   （1）中間的Button用下面的方式面出來：

    <Button Width="100" Height="40">
               <Canvas>
                   <Path Stroke="Blue" Data="M -30, -5 l 40,0 l0,-6 l 20,10 l-20,10 l0,-6 l-40,0 Z">
                   </Path>
               </Canvas>
   </Button>

   （2）爲在後臺代碼中訪問控件，需要給它命名，如

   <ListBox x:Name="lstSource"></ListBox>

   （3）響應ComboBox的SelectionChanged事件，獲取到選定內容的方法是：          

   ComboBox cb = sender as ComboBox;
   
   ComboBoxItem item = cb.SelectedItem as ComboBoxItem;
   
   string selected = item.Content.ToString();

   然後通過switch語句分別處理長度、重量等選項。

5. 對於長度等單位，可構建如下字典對象輔助轉換：

Dictionary<string, double> length = new Dictionary<string, double>

        { {"m(米)", 1 },  {"cm(釐米)", 0.01 }, {"mm(毫米)", 0.001 }};

但溫度不行，需自行轉換。

三、程序代碼

UI設計

<Window x:Class="Homework10.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:Homework10"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800" Loaded="Window_Loaded">
    <Grid Loaded="Grid_Loaded">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="1*"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition/>
            <ColumnDefinition/>
            <ColumnDefinition/>
        </Grid.ColumnDefinitions>
        <TextBlock Grid.Row="0" Grid.Column="0"
            HorizontalAlignment="Center" TextWrapping="Wrap" Text="請選擇單位類別" VerticalAlignment="Center"/>
        <ComboBox Grid.Column="1" Grid.Row="0" x:Name="comboTypes" SelectionChanged="ComboTypes_SelectionChanged">
            <ComboBoxItem>長度</ComboBoxItem>
            <ComboBoxItem>質量</ComboBoxItem>
            <ComboBoxItem>溫度</ComboBoxItem>
        </ComboBox>
        <TextBlock  Grid.Row="1" Grid.Column="0"
            HorizontalAlignment="Center" TextWrapping="Wrap" Text="請輸入原始數據" VerticalAlignment="Center"/>
        <TextBox  x:Name="lstvalText" Grid.Column="1" Grid.Row="1" TextWrapping="Wrap" Text="0" TextChanged="Cal_Text"/>
        <TextBlock  x:Name="lstText" Grid.Row="1" Grid.Column="2"
            HorizontalAlignment="Center" TextWrapping="Wrap" Text="原始單位" VerticalAlignment="Center" />
        <TextBlock  Grid.Row="2" Grid.Column="0"
            HorizontalAlignment="Center" TextWrapping="Wrap" Text="換算結果" VerticalAlignment="Center"/>
        <TextBox x:Name="tndvalText" Grid.Row="2" Grid.Column="1" TextWrapping="Wrap"  Text="0" IsEnabled="False"/>
        <TextBlock  x:Name="tndText"  Grid.Row="2" Grid.Column="2"
            HorizontalAlignment="Center" TextWrapping="Wrap" Text="換算單位" VerticalAlignment="Center"/>
        <TextBlock  x:Name="errText"  Grid.Row="3" Grid.ColumnSpan="3" TextWrapping="Wrap" Text="" />
        <ListBox x:Name="lstSource" Grid.Row="4" Grid.Column="0" SelectionChanged="LstSource_SelectionChanged"/>
        <Button Grid.Column="1" Grid.Row="4" Width="160" Height="40" Click="CalBtn_Click">
            <Canvas>
                <Path Stroke="Blue" Data="M -30, -5 l 40,0 l0,-6 l 20,10 l-20,10 l0,-6 l-40,0 Z">
                </Path>
            </Canvas>
        </Button>
        <ListBox x:Name="tndSource" Grid.Row="4" Grid.Column="2" SelectionChanged="TndSource_SelectionChanged"/>
    </Grid>
</Window>

 

邏輯設計 

using System;
using System.Collections.Generic;
using System.ComponentModel;
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;

namespace Homework10
{
    /// <summary>
    /// MainWindow.xaml 的交互邏輯
    /// </summary>
    public partial class MainWindow : Window
    {
        Dictionary<string, double> length = new Dictionary<string, double>
        { {"m(米)", 1 },  {"cm(釐米)", 0.01 }, {"mm(毫米)", 0.001 }};
        Dictionary<string, double> mass = new Dictionary<string, double>
        { {"k(克)", 1 },  {"jin(斤)", 500 }, {"kg(千克)", 1000 }};
        List<string> items = new List<string>() { "攝氏度", "華氏度" };
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Grid_Loaded(object sender, RoutedEventArgs e)
        {
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            
            lstSource.ItemsSource = length.Keys;
            tndSource.ItemsSource = length.Keys;
            comboTypes.SelectedIndex = 0;
        }
        private void LstSource_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            ListBox listBox1 = sender as ListBox;
            string txt = listBox1.SelectedItem as string;
            lstText.Text = txt;

        }
        private void TndSource_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            ListBox listBox2 = sender as ListBox;
            string txt = listBox2.SelectedItem as string;
            tndText.Text = txt;
        }
        private void ComboTypes_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            ComboBox cb = sender as ComboBox;
            ComboBoxItem item = cb.SelectedItem as ComboBoxItem;
            string selected = item.Content.ToString();
            if (selected == "長度") 
            {
                lstSource.ItemsSource = length.Keys;
                tndSource.ItemsSource = length.Keys;
            }
            else if (selected == "質量")
            {
                lstSource.ItemsSource = mass.Keys;
                tndSource.ItemsSource = mass.Keys;
            }
            else if (selected == "溫度")
            {
                lstSource.ItemsSource = items;
                tndSource.ItemsSource = items;
            }
        }

        private void CalBtn_Click(object sender, RoutedEventArgs e)
        {
            
        }

        private void Cal_Text(object sender, TextChangedEventArgs e)
        {
            if (lstSource == null || tndSource == null)
                return;
            if(errText!=null)
                errText.Text = "";
            if (lstvalText.Text == "" || lstSource.SelectedIndex == -1 || tndSource.SelectedIndex == -1) {
                tndvalText.Text = "0";
                return;
            }
            try
            {
                tndvalText.Text = "0";
                double a = double.Parse(lstvalText.Text);
                if (comboTypes.SelectedIndex == 0)
                {
                    tndvalText.Text = (a * length[lstText.Text] / length[tndText.Text]).ToString();
                }
                else if (comboTypes.SelectedIndex == 1)
                {
                    tndvalText.Text = (a * mass[lstText.Text] / mass[tndText.Text]).ToString();
                }
                else if (comboTypes.SelectedIndex == 2)
                {
                    if (lstSource.SelectedIndex == 0)
                    {
                        tndvalText.Text = (a * 1.8 + 32).ToString();
                    }
                    else
                    {
                        tndvalText.Text = ((a - 32) / 1.8).ToString();
                    }
                }
            }
            catch (FormatException fe)
            {
                errText.Text = "數據格式錯誤:" + fe.Message;
            }
            catch (KeyNotFoundException kfe) {

                errText.Text = "單位錯誤：" + kfe.Message;
            }
          
        }
    }
}

四、運行結果

五、實驗心得與體會

1. 熟悉使用WPF進行界面編程的基本過程；
2. 掌握WPF佈局、控件、事件的使用。

參考文章

https://baike.baidu.com/item/%E5%8D%8E%E6%B0%8F%E5%BA%A6/9982416?fr=aladdin#2

https://docs.microsoft.com/zh-cn/dotnet/framework/wpf/controls/how-to-get-a-listboxitem

https://blog.csdn.net/weixin_44543135/article/details/98762476