Question

使用Silverlight 4工具包图表控件，我试图在运行时创建一个100％的图表，而在XAML中没有任何证据。为此，我在页面加载时创建空白图表：

        Chart TrendChart = new Chart();
        TrendChart.Name = "TrendChart";
        TrendChart.Title = "Call History";
        TrendChart.HorizontalContentAlignment = System.Windows.HorizontalAlignment.Stretch;
        TrendChart.HorizontalAlignment = System.Windows.HorizontalAlignment.Stretch;
        TrendChart.VerticalAlignment = System.Windows.VerticalAlignment.Stretch;
        TrendChart.VerticalContentAlignment = System.Windows.VerticalAlignment.Stretch;

        GridPanel.Children.Add(TrendChart);

用户单击按钮以检索数据后，将创建此自定义类的列表：

    private class PhoneTrendDataPoint
    {
        public string XValue { get; set; }
        public double YValue { get; set; }
    }

我使用名为CurrentCallTrends的List作为我的图表的ItemsSource。

        // Update the chart with the received data
        Chart TrendChart = (Chart)this.FindName("TrendChart");

        // Wipe out previous chart data
        TrendChart.Series.Clear();



        // set the data
        ColumnSeries columnSeries = new ColumnSeries();
        columnSeries.Name = "Current Call Volume";
        columnSeries.ItemsSource = CurrentCallTrends;
        //columnSeries.SetBinding(ColumnSeries.ItemsSourceProperty, new Binding("CurrentCallTrends"));
        columnSeries.DependentValueBinding = new Binding("XValue");
        columnSeries.IndependentValueBinding = new Binding("YValue");
        TrendChart.Series.Add(columnSeries);

问题是我遇到运行时错误，它提示我打开一个关于未设置为对象实例的对象引用的调试器。如果我将该行注释为.SetBinding，则ItemsSource将消失并且不会显示任何数据，但至少没有运行时错误。

我错过了什么？

Answer 1

在进行了额外的谷歌搜索之后，我做了一些似乎有效的修改但是没有让我觉得这是最好的方法。现在显示数据，但除非没有更好的方法，否则我不接受这个答案：

        // Update the chart with the received data
        Chart TrendChart = (Chart)this.FindName("TrendChart");

        // Wipe out previous chart data
        TrendChart.Series.Clear();


        // test data
        KeyValuePair<string, double>[] CurrentCallData = new KeyValuePair<string, double>[CurrentCallTrends.Count];
        for (int i = 0; i < CurrentCallTrends.Count; i++)
        {
            CurrentCallData[i] = new KeyValuePair<string, double>(CurrentCallTrends[i].XValue, CurrentCallTrends[i].YValue);
        }



        // set the data
        ColumnSeries columnSeries = new ColumnSeries();
        columnSeries.Name = "CurrentCallVolume";
        columnSeries.Title = "Current Call Volume";
        columnSeries.SetBinding(ColumnSeries.ItemsSourceProperty, new Binding());
        //columnSeries.ItemsSource = CurrentCallTrends;
        columnSeries.ItemsSource = CurrentCallData;
        columnSeries.DependentValueBinding = new Binding("Value");
        columnSeries.IndependentValueBinding = new Binding("Key");
        TrendChart.Series.Add(columnSeries);

        //this.DataContext = CurrentCallTrends;

在运行时创建的Silverlight 4图表不会显示数据

1 个答案: