我需要在WPF项目中实现一个简单的柱状图输出。我选择了OxyPlot库来完成。设计模式当然是MVVM。
相关的源代码部分如下所示。当我运行项目时,我得到的是一个空的图表,x轴上有1到5个类别(这是正确的),y轴上有0到100的值(这也是正确的,因为我应该显示百分比)。
数据集合(命名为“difficulties”用于类别轴和“percentages”用于值轴)已经正确地填充了值,我已经检查过了。
但是没有显示任何柱形。所以我想知道我做错了什么。我根据this oxyplot demo建立了我的示例,并基于我们在大学wpf课程上展示的一个示例。
有什么建议吗?
问候 Roland
数据集合(命名为“difficulties”用于类别轴和“percentages”用于值轴)已经正确地填充了值,我已经检查过了。
但是没有显示任何柱形。所以我想知道我做错了什么。我根据this oxyplot demo建立了我的示例,并基于我们在大学wpf课程上展示的一个示例。
有什么建议吗?
问候 Roland
using System;
using System.ComponentModel;
using System.Linq.Expressions;
namespace GeoCaching.Wpf.ViewModels
{
public abstract class ViewModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
protected void RaisePropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
Console.WriteLine("PropertyChangedEventArgs called " + propertyName);
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
}
统计模型本身放在这里:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using GeoCaching.BL;
using GeoCaching.BL.Interfaces;
using GeoCaching.BL.Factories;
using GeoCaching.DAL.Common.Domain;
using GeoCaching.Wpf.ViewModels;
using OxyPlot;
using OxyPlot.Wpf;
using OxyPlot.Annotations;
using OxyPlot.Axes;
namespace GeoCaching.Wpf.ViewModels
{
public class StatisticsVM : ViewModelBase
{
private IStatisticsMgr statManager;
Dictionary<int, double> testList;
List<int> difficulties;
List<double> percentages;
public StatisticsVM()
{
PlotModel = new PlotModel();
this.difficulties = new List<int>();
this.percentages = new List<double>();
LoadData();
SetUpModel();
}
private PlotModel plotModel;
public PlotModel PlotModel
{
get { return plotModel; }
set { plotModel = value; OnPropertyChanged("PlotModel"); }
}
private void SetUpModel()
{
var temp = new PlotModel("difficulties distribution");
OxyPlot.Axes.CategoryAxis catAxis = new OxyPlot.Axes.CategoryAxis(AxisPosition.Bottom);
OxyPlot.Axes.LinearAxis valAxis = new OxyPlot.Axes.LinearAxis(AxisPosition.Left, 0, 100);
valAxis.MinimumPadding = 0;
valAxis.AbsoluteMinimum = 0;
OxyPlot.Series.ColumnSeries cs = new OxyPlot.Series.ColumnSeries();
cs.ItemsSource = percentages;
temp.Axes.Add(catAxis);
temp.Axes.Add(valAxis);
temp.Series.Add(cs);
PlotModel = temp;
PlotModel.RefreshPlot(true);
}
//fetch statistics data from
//database
private void LoadData()
{
statManager = StatisticsMgrFactory.GetStatisticsManager();
testList = new Dictionary<int, double>();
testList = statManager.GroupByDifficulty();
//extract keys and values
//for statistical display on axes
foreach (KeyValuePair<int,double> item in testList)
{
difficulties.Add(item.Key);
percentages.Add(item.Value);
}
}
}
}
XAML窗口背后的代码:
using GeoCaching.Wpf.ViewModels;
namespace GeoCaching.Wpf
{
/// <summary>
/// Interaction logic for ChartTest.xaml
/// </summary>
public partial class ChartTest : Window
{
public ChartTest()
{
InitializeComponent();
this.DataContext = new StatisticsVM();
}
}
}
以及 XAML 本身:
<Window x:Class="GeoCaching.Wpf.ChartTest"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:oxy="http://oxyplot.codeplex.com"
Title="ChartTest" Height="300" Width="300">
<Grid>
<oxy:Plot Title="Bar series" LegendPlacement="Outside" LegendPosition="RightTop" LegendOrientation="Vertical" Model="{Binding PlotModel}">
</oxy:Plot>
</Grid>
</Window>