带有MS Chart Control VB的交互式图表 [英] Interactive Chart with MS Chart Control VB

问题描述

您好，我目前正在创建图表和img并在视图中显示。但是我想使其更具交互性……例如。当用户将mose放在点上（在点图中）时，他可以看到该点的值。

Hi I'am currently creating a Chart to and img and display it in view. But I would like to make it a little more interactive ... eg. when user put mose over point (in point chart) he can see the values of this point.

在这里，我创建了图表并显示了图像

Here I create and image of an chart

Function GenerateChart(id As Integer, width As Integer, height As Integer) As ActionResult

    ' Creating chart
    Dim chart = New Chart()
    Dim area = New ChartArea()
    Dim series = New Series()

    chart.Width = width
    chart.Height = height

    ' Adding Series to the Chart
    chart.Series.Add("ValueSeries")
    chart.Series("ValueSeries").XValueMember = "Date"
    chart.Series("ValueSeries").YValueMembers = "Value"
    chart.Series("ValueSeries").ChartType = SeriesChartType.Point
    'chart.Series("ValueSeries1").AxisLabel = "Label"

    ' Getting data for series
    chart.DataSource = GetDataForChart(id)
    chart.DataBind()

    chart.ChartAreas.Add(New ChartArea())

    ' Saving chart as file
    Dim returnVal = New MemoryStream()
    chart.SaveImage(returnVal)

    'Return adress for file
    Return File(returnVal.GetBuffer(), "image/png")
End Function

有没有我可以添加以使其具有交互性的特殊属性？如果我添加它们，也许我应该返回比图像更复杂的东西？\

are there any special properties that i may add to make it interactive ? And if I add them maybe I should return something diffrant than an image ?\

编辑1

I已经阅读了有关工具提示的信息....，但是您必须为每个系列值设置每个工具提示，但我不确定将图表另存为img时是否可以使用工具提示，但会尝试使用

I have read about tool tips .... but you have to set each tooltip for each series value and still i am not sure if tooltips works when you save chart as img but 'll try it

推荐答案

您可以将Chart.HitTest方法与MouseMove事件一起使用，以检查鼠标是否位于数据点上。这是一个示例

You can use the Chart.HitTest method together with the MouseMove event to check for the mouse being over a datapoint. Here is an example

Public Class Form1
    Dim ToolTipProvider As New ToolTip

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        For i = 1 To 20
            Chart1.Series(0).Points.AddXY(i, i ^ 2)
        Next
    End Sub

    Private Sub Chart1_MouseMove(sender As Object, e As MouseEventArgs) Handles Chart1.MouseMove
        Dim h As Windows.Forms.DataVisualization.Charting.HitTestResult = Chart1.HitTest(e.X, e.Y)
        If h.ChartElementType = DataVisualization.Charting.ChartElementType.DataPoint Then
            ToolTipProvider.SetToolTip(Chart1, h.Series.Points(h.PointIndex).XValue & " x " & h.Series.Points(h.PointIndex).YValues(0))
        End If
    End Sub
End Class

它首先执行HitTest并将结果分配给变量 h 。
HitTestResult的ChartElementType属性定义在给定坐标处的元素类型。如果它是一个数据点，则将带有坐标的相应工具提示分配给图表。

It first performs a HitTest and assigns the result to the variable h. The property ChartElementType of the HitTestResult defines what elementtype is located at the given coordinates. If it is a datapoint a corresponding tooltip with the coordinates is assigned to the chart.

如果您在临时图片中执行此操作，则需要在您的方法中执行HitTest并在图片。我不知道为什么要用这种方法，但是要使图像具有交互性并不容易。

If you do it in a temporary image you need to perform the HitTest in your method and draw the tooltip on the image. I don't know why you do it this way, but making an image interactive is not easily done.

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