从最简单的开始 - 格式化标签可以做到像这样:你可以这样做
myPane.Y2Axis.Scale.Format = "HH:mm";
一种方法(和它感觉有点片状,但我会让你决定的)就是一旦超出阈值(在这种情况下超过30分钟),就从曲线上移除这些点。这样当图表重绘轴时会相应更新。
我觉得取规模最小的值可能会比这更好的办法,但做不到这一点,你可以简单地保持队列为你加分,像这样,然后当他们超越你的门槛删除:
private Queue<DateTime> axisTimes;
private static readonly Random rnd = new Random();
private void button1_Click(object sender, EventArgs e)
{
GraphPane myPane = zg1.GraphPane;
myPane.XAxis.IsVisible = false;
myPane.X2Axis.IsVisible = true;
myPane.X2Axis.MajorGrid.IsVisible = true;
myPane.X2Axis.Scale.Min = 0;
myPane.X2Axis.Scale.Max = 600;
myPane.YAxis.IsVisible = false;
myPane.Y2Axis.IsVisible = true;
myPane.Y2Axis.Scale.MajorUnit = DateUnit.Minute;
myPane.Y2Axis.Scale.MinorUnit = DateUnit.Second;
myPane.Y2Axis.Scale.Format = "HH:mm";
myPane.Y2Axis.Type = AxisType.DateAsOrdinal;
LineItem myCurve = myPane.AddCurve("Alpha",
new PointPairList(),
Color.Red,
SymbolType.None);
myCurve.Symbol.Fill = new Fill(Color.White);
myCurve.IsX2Axis = true;
myCurve.IsY2Axis = true;
myPane.Chart.Fill = new Fill(Color.White, Color.LightGray, 45.0f);
zg1.IsShowPointValues = true;
axisTimes = new Queue<DateTime>();
var t = new System.Windows.Forms.Timer();
t.Interval = 1000;
t.Tick += ShowData;
Thread.Sleep(100);
t.Start();
}
private void ShowData(object sender, EventArgs e)
{
var t = (System.Windows.Forms.Timer) sender;
t.Enabled = false;
int x = rnd.Next(500, 600);
var y = new XDate(DateTime.Now);
var myCurve = zg1.GraphPane.CurveList[0];
if (axisTimes.Any())
{
// Remove any points that go beyond our time threshold
while ((((DateTime)y) - axisTimes.Peek()).TotalMinutes > 30)
{
myCurve.RemovePoint(0);
axisTimes.Dequeue();
if (!axisTimes.Any())
{
break;
}
}
}
// Add the new point and store the datetime that it was added in
// our own queue
axisTimes.Enqueue(y);
myCurve.AddPoint(x, y);
zg1.AxisChange();
zg1.Invalidate();
t.Enabled = true;
}
来源
2012-04-19 10:07:13
kmp
该轴仅显示大约5分钟的数据 - 在显示30分钟之前它不会“移动” - 将代码中的TotalMinutes值调整为2,以了解我的意思。 – kmp 2012-04-19 10:41:24