Microsoft图表控件的示例环境）

  //为数据点系列设置工具提示
 chart1.Series [0] .ToolTip =Percent：#PERCENT; 

 //为图例项设置工具提示
 chart1.Series [0] .LegendToolTip =#LABEL中的收入为#VAL million; 

 //为数据点标签设置工具提示
 chart1.Series [0] .LabelToolTip =#PERCENT; 

 //为第二个数据点设置工具提示
 chart1.Series [0] .Points [1] .ToolTip =Unknown; 
 

I am using MS Chart control to draw graphs on Winform.

I want to show the current (x,y) Value as tooltip on Mousedown on chartarea.

How do I do that?

From the chart samples (Samples Environments for Microsoft Chart Controls)

// Set ToolTips for Data Point Series
chart1.Series[0].ToolTip = "Percent: #PERCENT";

// Set ToolTips for legend items
chart1.Series[0].LegendToolTip = "Income in #LABEL  is #VAL million";

// Set ToolTips for the Data Point labels
chart1.Series[0].LabelToolTip = "#PERCENT";

// Set ToolTips for second Data Point
chart1.Series[0].Points[1].ToolTip = "Unknown";