切换到MVVM问题

Question

我是MVVM的新手。目前，我所有的代码都是在链接到XAML的.cs文件中编写的。我想切换到MVVM，但遇到了困难。我将尝试解释原因：

我在.cs文件中指定了许多不同的图表控件和输入数据，我直接访问图表对象，并通过编程使用它的属性为图表添加点。

示例：

foreach (var group in qcv.Groups)
{
    AreaSeries areaSeries = new AreaSeries();
    areaSeries.CombineMode = Telerik.Charting.ChartSeriesCombineMode.Stack;
    areaSeries.ValueBinding = new PropertyNameDataPointBinding("Rev");
    areaSeries.CategoryBinding = new PropertyNameDataPointBinding("Date");
    areaSeries.ItemsSource = group as IEnumerable;
    RadChart1.Series.Add(areaSeries);
}

但只要我切换到MVVM，ViewModel文件中的RadChart1对象就无法访问。我如何使它在ViewModel类中可见，或者您可以建议更好的方法，如何在不更改代码的情况下获取该对象并为图表提供输入？

我的XAML文件：

<UserControl x:Class="FrontEnd.RevenueChart"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:FrontEnd"
             mc:Ignorable="d" xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation" HorizontalAlignment="Stretch" >
    <UserControl.DataContext>
        <local:RevenueChartViewModel/>
    </UserControl.DataContext>
    <Grid>
        <telerik:RadCartesianChart HorizontalAlignment="Stretch" x:Name="RadChart1" Palette="Metro" Zoom="10,1">
            <telerik:RadCartesianChart.HorizontalAxis>
                <telerik:CategoricalAxis/>
            </telerik:RadCartesianChart.HorizontalAxis>
            <telerik:RadCartesianChart.VerticalAxis>
                <telerik:LinearAxis/>
            </telerik:RadCartesianChart.VerticalAxis>
            <telerik:RadCartesianChart.Behaviors>
                <telerik:ChartPanAndZoomBehavior ZoomMode="Both">
                </telerik:ChartPanAndZoomBehavior>
            </telerik:RadCartesianChart.Behaviors>
        </telerik:RadCartesianChart>
    </Grid>
</UserControl>

Answer 1

从视图模型访问视图控件是MVVM领域的一大禁忌。你必须颠倒你的想法：与其把东西添加到Series，不如把Series绑定到东西上。使用SeriesMapping s获取图表控件以将您的组转换为系列。下面是一些让你开始的即兴代码：

<telerik:RadCartesianChart HorizontalAlignment="Stretch"
  Palette="Metro" Zoom="10,1"
  Series="{Binding Groups}"><!-- <=== this is the important part -->
  <telerik:RadChart.SeriesMappings>
    <telerikCharting:SeriesMapping LegendLabel="Product Sales">
      <telerikCharting:SeriesMapping.SeriesDefinition>
        <telerikCharting:AreaSeriesDefinition/>
      </telerikCharting:SeriesMapping.SeriesDefinition>
      <telerikCharting:SeriesMapping.ItemMappings>
        <telerikCharting:ItemMapping DataPointMember="XCategory" FieldName="Date"/>
        <telerikCharting:ItemMapping DataPointMember="YValue" FieldName="Rev"/>
      </telerikCharting:SeriesMapping.ItemMappings>
    </telerikCharting:SeriesMapping>
  </telerik:RadChart.SeriesMappings>
  ...