Question

我已将注释与数据点对齐;我想垂直对齐注释。

我已经读过这篇文章，但无法弄清楚如何将图表宽度与数据点联系起来。 https://msdn.microsoft.com/en-us/library/dd456731.aspx

而且：MS Charting Annotations refuse to align to mouse position

到目前为止，我添加了图表的图片。

'create new chart
 chart1 = New DataVisualization.Charting.Chart

 'add chart areas
  chart1.ChartAreas.Add("NewChartArea")
  chart1.ChartAreas("NewChartArea").Area3DStyle.Enable3D = False
  chart1.ChartAreas("NewChartArea").AxisX.MajorGrid.Enabled = False 'turn chart background grid on and off
  chart1.ChartAreas("NewChartArea").AxisY.MajorGrid.Enabled = False 'turn chart background grid on and off
  chart1.ChartAreas("NewChartArea").AxisX.Title = "Activities of daily living" '----> title on the bottom for the x axis
  '[template] chart1.ChartAreas("NewChartArea").AxisX.LabelStyle.Angle = 45
  '[template] Chart1.Series(SeriesZeroChartName).Label = " my own label" ' -----> adds a label at the top of each bar

   For c As Integer = 2 To Me.DataGridViewResultsAdls.ColumnCount - 1

        Dim NextSeriesChartName As String
        NextSeriesChartName = DataGridViewResultsAdls.Columns(c).Name

        chart1.Series.Add(NextSeriesChartName)
        chart1.Series(NextSeriesChartName).ChartType = DataVisualization.Charting.SeriesChartType.Bar 'CHART CHANGER ******  change this value to change chart type
        chart1.Series(NextSeriesChartName).Points.Clear()
        chart1.Series(NextSeriesChartName).IsValueShownAsLabel = True '----> puts little labels ontop of each bar
        chart1.Series(NextSeriesChartName).SmartLabelStyle.Enabled = True


       ' fill each subsequent series with points
         For Count As Integer = 0 To DataGridViewResultsAdls.Rows.Count - 2
                Dim NextColumnName As String
                NextColumnName = DataGridViewResultsAdls.Columns(c).Name

                ' define X values
                Dim XLabelMyCustom As String
                XLabelMyCustom = DataGridViewResultsAdls.Item(0, Count).Value
                'define Y values
                Dim YLabelMyCustom As String
                YLabelMyCustom = DataGridViewResultsAdls.Item(NextColumnName, Count).Value

                ' add the point to the chart
                chart1.Series(NextSeriesChartName).Points.AddXY(XLabelMyCustom, YLabelMyCustom)

                ' create custom labels for the x axis
                chart1.ChartAreas("NewChartArea").AxisX.CustomLabels.Add(Count + 0.5, Count + 0.4 + 0.5, "Q2", 0, DataVisualization.Charting.LabelMarkStyle.None)
                chart1.ChartAreas("NewChartArea").AxisX.CustomLabels.Add(Count + 0.5 + 0.5, Count + 0.9 + 0.5, "Q1", 0, DataVisualization.Charting.LabelMarkStyle.None)
                chart1.ChartAreas("NewChartArea").AxisX.CustomLabels.Add(Count + 0.5, Count + 1, "Q3", 2, DataVisualization.Charting.LabelMarkStyle.LineSideMark)



                'Create a variable MyDataPoint to hold the current datapoint
                Dim MyDataPoint As DataPoint
                MyDataPoint = chart1.Series(NextSeriesChartName).Points(Count)
                'Create a new text annotation
                Dim MyTextAnnotation As TextAnnotation
                MyTextAnnotation = New TextAnnotation
                MyTextAnnotation.Text = "some notation"
                '[template] MyTextAnnotation.X =   <---- sets coordinates on screen for x
                '[template ]MyTextAnnotation.Y =   <---- sets coordinates on screen for y
                '[template] MyTextAnnotation.AnchorDataPoint = MyDataPoint  'sets the point where the notation will be
                '[template] chart1.Annotations.Add(MyTextAnnotation) ' adds the notation to the chart

                ' only add annotations to the chart once per series
                If c = 2 Then
                    MyTextAnnotation.AxisY = chart1.ChartAreas("NewChartArea").AxisY

                    ' [template] chart1.Series(NextSeriesChartName).Points.Item(Count).ToString  <--- output points to a string {x,y}


                    MyTextAnnotation.AnchorDataPoint = MyDataPoint  'sets the point where the notation will be
                    chart1.Annotations.Add(MyTextAnnotation) ' adds the notation to the chart
                    MyTextAnnotation.AnchorOffsetX = -10


                End If
            Next

        Next

        'Add chart to control and set dock to fill
        Me.PanelChartAdls.Controls.Add(chart1)
        chart1.Dock = DockStyle.Fill

    End If

Answer 1

在Chart控件中定位相当复杂。

首先，图表有三个坐标系：

数据值
某些区域的百分比，最值得注意的是ChartArea和InnerPlotPosition
Chart控件的ClientArea

实现Annotations对齐的最简单方法是首先将每个对齐到DataPoint：

MyTextAnnotation.AnchorDataPoint = MyDataPoint

接下来，您将X-Position覆盖为您喜欢的值：

MyTextAnnotation.X = someValue;

一些注意事项：

虽然默认，但Annotation.Position会使用percentages，在锚定之后 DataPoint ，它会使用值代替。所以使用50不会放在中间的某个地方，而是放在右边......

查看您的图表我建议使用值3。

如果您的值有所不同，此定位也会有所不同。当您调整图表大小时，轴将调整大小并且注释也会移动。

Btw：百分比与下一个外部容器有关：ChartAreas到Chart.ClientRectangle，InnerPlotPostion到ChartArea以及每个元素到容器它停靠在..

默认情况下，Positions设置为自动，因此其值为NaN。要访问（当前）值，您可以调用ElementPosition.ToRectangleF()。
另请注意，Chart's Axes上有几个函数可以转换值，像素和百分比位置。

但是，您需要找到有效的时刻来调用这些功能;如果Chart未完成布局，则会返回null。

您可以安全地在三个Paint事件之一中调用它们，或者响应用户交互（如鼠标事件）。

以下是如何使用它们将所有Annotations定位到（某种程度上）固定的像素位置：

private void chart1_PostPaint(object sender, ChartPaintEventArgs e)
{
    Axis AY = chart1.ChartAreas[0].AxisY;

    double pypx = AY.ValueToPosition(AY.PixelPositionToValue(30));

    foreach (TextAnnotation ta in chart1.Annotations)
    {
        ta.X = pypx;
    }
}

现在，在调整图表大小或数据值增大或缩小时，Annotations不会移动。至少不是很多;可以看到一些跳跃。要么是因为我错过了某些东西，要么是因为四舍五入问题。

但我建议采用更简单的方法将X-Position设置为轴上的固定值..：

MyTextAnnotation.X = 3;

这会把它们放在你画的黄线上。

图表注释：如何沿数据点的轴对齐注释

1 个答案: