如何在使用鼠标滚轮时启用 Microsoft Chart 控件的缩放功能
我有以下代码,想知道如何制作此事件?它属于哪个类别?
private void chData_MouseWheel(object sender, MouseEventArgs e)
{
try
{
if (e.Delta < 0)
{
chart1.ChartAreas[0].AxisX.ScaleView.ZoomReset();
chart1.ChartAreas[0].AxisY.ScaleView.ZoomReset();
}
if (e.Delta > 0)
{
double xMin = chart1.ChartAreas[0].AxisX.ScaleView.ViewMinimum;
double xMax = chart1.ChartAreas[0].AxisX.ScaleView.ViewMaximum;
double yMin = chart1.ChartAreas[0].AxisY.ScaleView.ViewMinimum;
double yMax = chart1.ChartAreas[0].AxisY.ScaleView.ViewMaximum;
double posXStart = chart1.ChartAreas[0].AxisX.PixelPositionToValue(e.Location.X) - (xMax - xMin) / 4;
double posXFinish = chart1.ChartAreas[0].AxisX.PixelPositionToValue(e.Location.X) + (xMax - xMin) / 4;
double posYStart = chart1.ChartAreas[0].AxisY.PixelPositionToValue(e.Location.Y) - (yMax - yMin) / 4;
double posYFinish = chart1.ChartAreas[0].AxisY.PixelPositionToValue(e.Location.Y) + (yMax - yMin) / 4;
chart1.ChartAreas[0].AxisX.ScaleView.Zoom(posXStart, posXFinish);
chart1.ChartAreas[0].AxisY.ScaleView.Zoom(posYStart, posYFinish);
}
}
catch { }
}