/// <summary>
/// Create a TextLabel for each bar in the GraphPane.
/// Call this method only after calling AxisChange()
/// </summary>
/// <remarks>
/// This method will go through the bars, create a label that corresponds to the bar value,
/// and place it on the graph depending on user preferences. This works for horizontal or
/// vertical bars in clusters or stacks.</remarks>
/// <param name="pane">The GraphPane in which to place the text labels.</param>
/// <param name="isBarCenter">true to center the labels inside the bars, false to
/// place the labels just above the top of the bar.</param>
/// <param name="valueFormat">The double.ToString string format to use for creating
/// the labels
/// </param>
private void CreateBarLabels(GraphPane pane, bool isBarCenter, string valueFormat)
{
bool isVertical = pane.BarSettings.Base == BarBase.X;
// Make the gap between the bars and the labels = 2% of the axis range
float labelOffset;
if (isVertical)
{
labelOffset = (float)(pane.YAxis.Scale.Max - pane.YAxis.Scale.Min) * 0.02f;
}
else
{
labelOffset = (float)(pane.XAxis.Scale.Max - pane.XAxis.Scale.Min) * 0.02f;
}
// keep a count of the number of BarItems
int curveIndex = 0;
// Get a valuehandler to do some calculations for us
ValueHandler valueHandler = new ValueHandler(pane, true);
// Loop through each curve in the list
foreach (CurveItem curve in pane.CurveList)
{
// work with BarItems only
BarItem bar = curve as BarItem;
if (bar != null)
{
IPointList points = curve.Points;
// Loop through each point in the BarItem
for (int i = 0; i < points.Count; i++)
{
// Get the high, low and base values for the current bar
// note that this method will automatically calculate the "effective"
// values if the bar is stacked
double baseVal, lowVal, hiVal;
valueHandler.GetValues(curve, i, out baseVal, out lowVal, out hiVal);
// Get the value that corresponds to the center of the bar base
// This method figures out how the bars are positioned within a cluster
float centerVal = (float)valueHandler.BarCenterValue(bar,
bar.GetBarWidth(pane), i, baseVal, curveIndex);
// Create a text label -- note that we have to go back to the original point
// data for this, since hiVal and lowVal could be "effective" values from a bar stack
string barLabelText = (isVertical ? points[i].Y : points[i].X).ToString(valueFormat);
// Calculate the position of the label -- this is either the X or the Y coordinate
// depending on whether they are horizontal or vertical bars, respectively
float position;
if (isBarCenter)
{
position = (float)(hiVal + lowVal) / 2.0f;
}
else
{
position = (float)hiVal + labelOffset;
}
// Create the new TextObj
TextObj label;
if (isVertical)
{
label = new TextObj(barLabelText, centerVal, position);
}
else
{
label = new TextObj(barLabelText, position, centerVal);
}
// Configure the TextObj
label.Location.CoordinateFrame = CoordType.AxisXYScale;
label.FontSpec.Size = 12;
label.FontSpec.FontColor = Color.Black;
label.FontSpec.Angle = isVertical ? 90 : 0;
label.Location.AlignH = isBarCenter ? AlignH.Center : AlignH.Left;
label.Location.AlignV = AlignV.Center;
label.FontSpec.Border.IsVisible = false;
label.FontSpec.Fill.IsVisible = false;
// Add the TextObj to the GraphPane
pane.GraphObjList.Add(label);
}
}
curveIndex++;
}
}
public HorizontalBarDemo() : base("A sideways bar demo.\n" +
"This demo also shows how to add labels to the bars, in this " +
"case showing the value of each bar",
"HorizontalBar Demo", DemoType.Bar)
{
GraphPane myPane = base.GraphPane;
// Set the title and axis labels
myPane.Title.Text = "Horizontal Bar Graph";
myPane.XAxis.Title.Text = "Performance Factor";
myPane.YAxis.Title.Text = "Grouping";
// Enter some random data values
double[] y = { 100, 115, 75, -22, 98, 40, -10 };
double[] y2 = { 90, 100, 95, -35, 80, 35, 35 };
double[] y3 = { 80, 110, 65, -15, 54, 67, 18 };
// Generate a bar with "Curve 1" in the legend
BarItem myCurve = myPane.AddBar("Curve 1", y, null, Color.Red);
// Fill the bar with a red-white-red gradient
myCurve.Bar.Fill = new Fill(Color.Red, Color.White, Color.Red, 90F);
// Generate a bar with "Curve 2" in the legend
myCurve = myPane.AddBar("Curve 2", y2, null, Color.Blue);
// Fill the bar with a blue-white-blue gradient for a 3d look
myCurve.Bar.Fill = new Fill(Color.Blue, Color.White, Color.Blue, 90F);
// Generate a bar with "Curve 3" in the legend
myCurve = myPane.AddBar("Curve 3", y3, null, Color.Green);
// Fill the bar with a Green-white-Green gradient for a 3d look
myCurve.Bar.Fill = new Fill(Color.White, Color.Green, 90F);
// Draw the X tics between the labels instead of at the labels
myPane.YAxis.MajorTic.IsBetweenLabels = true;
// Set the XAxis to an ordinal type
myPane.YAxis.Type = AxisType.Ordinal;
// draw the X axis zero line
myPane.XAxis.MajorGrid.IsZeroLine = true;
//This is the part that makes the bars horizontal
myPane.BarSettings.Base = BarBase.Y;
// Fill the axis background with a color gradient
myPane.Chart.Fill = new Fill(Color.White,
Color.FromArgb(255, 255, 166), 45.0F);
base.ZedGraphControl.AxisChange();
// The ValueHandler is a helper that does some position calculations for us.
ValueHandler valueHandler = new ValueHandler(myPane, true);
// Display a value for the maximum of each bar cluster
// Shift the text items by 5 user scale units above the bars
const float shift = 3;
int ord = 0;
foreach (CurveItem curve in myPane.CurveList)
{
BarItem bar = curve as BarItem;
if (bar != null)
{
IPointList points = curve.Points;
for (int i = 0; i < points.Count; i++)
{
double xVal = points[i].X;
// Calculate the Y value at the center of each bar
double yVal = valueHandler.BarCenterValue(curve, curve.GetBarWidth(myPane),
i, points[i].Y, ord);
// format the label string to have 1 decimal place
string lab = xVal.ToString("F0");
// create the text item (assumes the x axis is ordinal or text)
// for negative bars, the label appears just above the zero value
TextObj text = new TextObj(lab, (float)xVal + (xVal > 0 ? shift : -shift),
(float)yVal);
// tell Zedgraph to use user scale units for locating the TextObj
text.Location.CoordinateFrame = CoordType.AxisXYScale;
text.FontSpec.Size = 10;
// AlignH the left-center of the text to the specified point
text.Location.AlignH = xVal > 0 ? AlignH.Left : AlignH.Right;
text.Location.AlignV = AlignV.Center;
text.FontSpec.Border.IsVisible = false;
// rotate the text 90 degrees
text.FontSpec.Angle = 0;
text.FontSpec.Fill.IsVisible = false;
// add the TextObj to the list
myPane.GraphObjList.Add(text);
}
}
ord++;
}
}
