从头实现一个WPF条形图

2022-08-07 08:11:46

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本文 Dotnet9 https://dotnet9.com 已收录，站长乐于分享dotnet相关技术，比如Winform、WPF、ASP.NET Core等，亦有C++桌面相关的Qt Quick和Qt Widgets等，只分享自己熟悉的、自己会的。

阅读导航：

一、先看效果
二、本文背景
三、代码实现
四、文章参考
五、代码下载

一、先看效果

二、本文背景

有没有这种场景：开源控件库或者收费的控件库，条形图或者柱状图都非常强大，但我的业务就是不符合，就是要自己设计呢？本文通过简单的实现一个条形图功能，以后类似的统计图可以在这上面进行修改，原理是类似的。

三、代码实现

小编使用.Net Core 3.1创建的WPF工程，创建名称为“BarChart”的解决方案后，添加名称为”Bar“的WPF用户控件，这个控件就是上图中的单个柱子，下面是Bar.xaml代码

 1 <UserControl x:Class="BarChart.Bar"
 2              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 3              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 4              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
 5              xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
 6              mc:Ignorable="d" 
 7              MinHeight="20" Width="Auto" Loaded="UserControl_Loaded">
 8     <Grid SizeChanged="Grid_SizeChanged">
 9         <Grid Background="{Binding Background,ElementName=border}" Opacity="0.3"/>
10         <Border x:Name="border" Background="{Binding Color}" VerticalAlignment="Bottom" Height="{Binding BarHeight}"/>
11         <TextBlock VerticalAlignment="Center" Margin="3" HorizontalAlignment="Center" Text="{Binding Value}" FontSize="20">
12             <TextBlock.Effect>
13                 <DropShadowEffect BlurRadius="1" ShadowDepth="0" Color="White"/>
14             </TextBlock.Effect>
15         </TextBlock>
16     </Grid>
17 </UserControl>

Bar.xaml.cs代码，主要是绑定前景色及背景色，及柱子百分比值。

 1 using System.ComponentModel;
 2 using System.Windows;
 3 using System.Windows.Controls;
 4 using System.Windows.Media;
 5 
 6 namespace BarChart
 7 {
 8     /// <summary>
 9     /// BarChart.xaml 的交互逻辑
10     /// </summary>
11     public partial class Bar  : UserControl, INotifyPropertyChanged
12     {
13         public event PropertyChangedEventHandler PropertyChanged;
14         private void NotifyPropertyChanged(string info)
15         {
16             if (PropertyChanged != null)
17             {
18                 PropertyChanged(this, new PropertyChangedEventArgs(info));
19             }
20         }
21 
22         private double _value;
23         public double Value
24         {
25             get { return _value; }
26             set
27             {
28                 _value = value;
29                 UpdateBarHeight();
30                 NotifyPropertyChanged("Value");
31             }
32         }
33 
34         private double maxValue;
35         public double MaxValue
36         {
37             get { return maxValue; }
38             set
39             {
40                 maxValue = value;
41                 UpdateBarHeight();
42                 NotifyPropertyChanged("MaxValue");
43             }
44         }
45 
46         private double barHeight;
47         public double BarHeight
48         {
49             get { return barHeight; }
50             set
51             {
52                 barHeight = value;
53                 NotifyPropertyChanged("BarHeight");
54             }
55         }
56 
57         private Brush color;
58         public Brush Color
59         {
60             get { return color; }
61             set
62             {
63                 color = value;
64                 NotifyPropertyChanged("Color");
65             }
66         }
67 
68         private void UpdateBarHeight()
69         {
70             if (maxValue > 0)
71             {
72                 var percent = (_value * 100) / maxValue;
73                 BarHeight = (percent * this.ActualHeight) / 100;
74             }
75         }
76 
77         public Bar()
78         {
79             InitializeComponent();
80 
81             this.DataContext = this;
82             color = Brushes.Black;
83         }
84 
85 
86         private void UserControl_Loaded(object sender, RoutedEventArgs e)
87         {
88             UpdateBarHeight();
89         }
90 
91         private void Grid_SizeChanged(object sender, SizeChangedEventArgs e)
92         {
93             UpdateBarHeight();
94         }
95     }
96 }

主窗体MainWindow.xaml，添加显示的业务数据，目前只是展示了进度值，其他标签只要你看懂了代码，很好加的，比如每根柱子，上面颜色显示一种意义名称、下面显示另一种意义名称。

 1 <Window x:Class="BarChart.MainWindow"
 2         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 3         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 4         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
 5         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
 6         xmlns:local="clr-namespace:BarChart"
 7         mc:Ignorable="d"
 8         Background="#FF252525" FontFamily="Nontserrrat"
 9         Title="MainWindow" Height="600" Width="1080" WindowStyle="None" ResizeMode="NoResize" WindowStartupLocation="CenterScreen">
10     <Grid>
11         <Grid.RowDefinitions>
12             <RowDefinition Height="70"/>
13             <RowDefinition Height="*"/>
14         </Grid.RowDefinitions>
15 
16         <Border BorderBrush="Gray" BorderThickness="0 0 0 1">
17             <TextBlock Text="Dotnet9.com" VerticalAlignment="Center" Margin="15"
18                        Foreground="White" FontSize="24"/>
19         </Border>
20 
21         <Border Grid.Row="1" Width="500" Height="300" VerticalAlignment="Top"
22                 HorizontalAlignment="Left" Margin="20" Background="White"
23                 BorderBrush="Gray" CornerRadius="12">
24             <Grid>
25                 <TextBlock Text="自定义条形图" Margin="10" FontSize="15"/>
26                 <StackPanel Orientation="Horizontal" Height="200" VerticalAlignment="Bottom">
27                     <local:Bar Background="#FF4455AA" Color="#FF88AA55" MaxValue="100" Value="80" Margin="5"/>
28                     <local:Bar Background="#FF4335AA" Color="#FF883355" MaxValue="100" Value="26" Margin="5"/>
29                     <local:Bar Background="#F26455AA" Color="#FF88A355" MaxValue="100" Value="49" Margin="5"/>
30                     <local:Bar Background="#FF4423AA" Color="#FF88A115" MaxValue="100" Value="23" Margin="5"/>
31                     <local:Bar Background="#FF4415AA" Color="#FF887955" MaxValue="100" Value="97" Margin="5"/>
32                     <local:Bar Background="#FF44513A" Color="#FF896A55" MaxValue="100" Value="68" Margin="5"/>
33                 </StackPanel>
34             </Grid>
35         </Border>
36     </Grid>
37 </Window>