图表中一个轴上的不同标签类型 [英] Different label types on one axis in chart
问题描述
我在我的应用程序中使用 System.Windows.Forms.DataVisualization.Charting
,我想在我的X轴上添加不同的标签类型,代表时间轴。例如,我想对标签使用HH:mm
格式,但是当 00:00
时喜欢显示dd.MM
格式。我尝试添加cutom标签,但它根本没有效果。
I'm using System.Windows.Forms.DataVisualization.Charting
in my app and I want to add different label types on my X axis which is representing a timeline. For example, I want to use "HH:mm"
format for labels but when it's 00:00
I'd like to show "dd.MM"
format instead. I tried to add cutom labels but it has no effect at all.
var area = new ChartArea();
area.AxisX.LabelStyle.Format = "HH:mm";
area.AxisX.Interval = 1 / 24.0;
area.AxisX.CustomLabels.Add(1.0, DateTimeIntervalType.Days, "dd.MM");
推荐答案
添加 CustomLabels
将帮助;但是如果您希望它们显示单独的格式,则必须将它们单独添加到每个 DataPoint
!
Adding CustomLabels
will help; however if you want them to show an individual format you will have to add them individually to each DataPoint
!
这样做并不像人们所希望的那么简单;有几个重载,但没有一个真的很容易使用。最简单的方法是imo,使用一个 FromPosition
和 ToPosition
;然后应以之间 DataPoints
的方式进行设置;
Doing so is not quite as simple as one could wish for; there are several overloads but none is really easy to use. The simplest way, imo, is to use one with a FromPosition
and a ToPosition
; these should then to be set in a way that they hit right between the DataPoints
; this way they will be centered nicely..
请注意,由于X值真的 DateTimes
,总是在图表中,转换为 doubles
,我们需要将它们转换回 DateTime
以获得正确的格式, 。
Note that as the X-Values are really DateTimes
, but as always in a chart, converted to doubles
we need to convert them back to DateTime
for correct formatting and also use their values to calculate the middle or rather half an interval..
这里是一个例子:
// prepare the test chart..
chart1.ChartAreas.Clear();
ChartArea CA = chart1.ChartAreas.Add("CA1");
Random R = new Random(123);
chart1.Series.Clear();
CA.AxisX.MajorTickMark.Interval = 1;
Series S = chart1.Series.Add("S1");
S.Points.Clear();
S.ChartType = SeriesChartType.Column;
S.SetCustomProperty("PixelPointWidth", "10");
// some random data:
DateTime dt0 = new DateTime(2015, 05, 01);
for (int i = 0; i< 40; i++)
{
int p = S.Points.AddXY(dt0.AddHours(i), R.Next(100));
}
// each custom label will be placed centered in a range
// so we need an amount of half an interval..
// this assumes equal spacing..
double ih = (S.Points[0].XValue - S.Points[1].XValue) / 2d;
// now we add a custom label to each data point
for (int i = 0; i < S.Points.Count; i++)
{
DataPoint pt = S.Points[i];
string s = (DateTime.FromOADate(pt.XValue)).ToString("HH:mm");
bool midnite = s == "00:00";
if (midnite) s = DateTime.FromOADate(pt.XValue).ToString("dd.MM.yyyy");
CustomLabel CL = CA.AxisX.CustomLabels.Add(pt.XValue - ih, pt.XValue + ih, s);
CL.ForeColor = midnite ? Color.Blue : Color.Black;
}
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