Question

我是MVVM的新手。目前我的所有代码都是用.cs文件编写的，该文件链接到XAML。我想切换到MVVM但遇到困难。我会尝试解释原因：

我在.cs文件中指定了许多不同的图表控件和输入数据，就像我直接访问Chart对象并使用它的属性programaticaly为我的图表添加点。

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);
}

但只要切换到MVVM RadChart1，ViewModel文件中的对象就无法访问。如何在ViewModel类中使其可见，或者您可以建议更好的方法如何获取该对象并为我的图表提供输入而不更改我的代码？

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领域的一个重要禁忌。你必须反思你的想法：不是向Series添加东西，而是将Series绑定到东西。使用SeriesMapping s获取图表控件以将您的组转换为系列。这里有一些让您入门的袖口代码：

<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>
  ...

切换到MVVM问题

1 个答案: