| GetColor |
| Returns the color at a particular point on the canvas. |
| Syntax | |
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[C#] XColor GetColor(int inX, int inY); XColor GetColor(XPoint inPoint); [Visual Basic] Function GetColor(inX As Integer, inY As Integer) As XColor Function GetColor(inPoint As XPoint) As XColor |
| Params | |
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| Name | Description | |||
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| inX | The horizontal coordinate at which you wish to sample the image color. | |||
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| inY | The vertical coordinate at which you wish to sample the image color. | |||
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| inPoint | The point at which you wish to sample the image color. | |||
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| return | The color at the point. | |||
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| Notes | |
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You may wish to find the color of the image at a particular point. Pass in a point and this function will return the color.
This operation is only valid for raster images. If the canvases are not raster based they will be rasterized.
| See Also | |
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| Example | |
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[C#]
Canvas canvas = new Canvas(200, 200);
DrawOptions drawOpts = new DrawOptions(DrawOptions.ShapeDrawingType.Both);
drawOpts.PenColor = new XColor(Color.Red);
drawOpts.PaintColor = new XColor(Color.Red);
canvas.DrawRect(new XRect(0, 0, 100, 100), drawOpts);
drawOpts.PenColor = new XColor(Color.Green);
drawOpts.PaintColor = new XColor(Color.Green);
canvas.DrawRect(new XRect(100, 0, 100, 100), drawOpts);
drawOpts.PenColor = new XColor(Color.Blue);
drawOpts.PaintColor = new XColor(Color.Blue);
canvas.DrawRect(new XRect(0, 100, 100, 100), drawOpts);
drawOpts.PenColor = new XColor(Color.Yellow);
drawOpts.PaintColor = new XColor(Color.Yellow);
canvas.DrawRect(new XRect(100, 100, 100, 100), drawOpts);
canvas.SaveAs(Server.MapPath("getcolor.gif"));
Canvas theImage = new Canvas(Server.MapPath("getcolor.gif"));
XColor theColor = new XColor();
theColor = theImage.GetColor(new XPoint(50, 50));
Response.Write("Top Left Color is " + theColor.String + "<br>\r\n");
theColor = theImage.GetColor(new XPoint(150, 50));
Response.Write("Top Right Color is " + theColor.String + "<br>\r\n");
theColor = theImage.GetColor(new XPoint(50, 150));
Response.Write("Bottom Left Color is " + theColor.String + "<br>\r\n");
theColor = theImage.GetColor(new XPoint(150, 150));
Response.Write("Bottom Left Color is " + theColor.String + "<br>\r\n");
[Visual Basic]
Dim canvas As New Canvas(200, 200)
Dim drawOpts As New DrawOptions(DrawOptions.ShapeDrawingType.Both)
drawOpts.PenColor = New XColor(Color.Red)
drawOpts.PaintColor = New XColor(Color.Red)
canvas.DrawRect(New XRect(0, 0, 100, 100), drawOpts)
drawOpts.PenColor = New XColor(Color.Green)
drawOpts.PaintColor = New XColor(Color.Green)
canvas.DrawRect(New XRect(100, 0, 100, 100), drawOpts)
drawOpts.PenColor = New XColor(Color.Blue)
drawOpts.PaintColor = New XColor(Color.Blue)
canvas.DrawRect(New XRect(0, 100, 100, 100), drawOpts)
drawOpts.PenColor = New XColor(Color.Yellow)
drawOpts.PaintColor = New XColor(Color.Yellow)
canvas.DrawRect(New XRect(100, 100, 100, 100), drawOpts)
canvas.SaveAs(Server.MapPath("getcolor.gif"))
Dim theImage As New Canvas(Server.MapPath("getcolor.gif"))
Dim theColor As New XColor()
theColor = theImage.GetColor(New XPoint(50, 50))
Response.Write("Top Left Color is " & theColor.[String] & "<br>" & vbCr & vbLf)
theColor = theImage.GetColor(New XPoint(150, 50))
Response.Write("Top Right Color is " & theColor.[String] & "<br>" & vbCr & vbLf)
theColor = theImage.GetColor(New XPoint(50, 150))
Response.Write("Bottom Left Color is " & theColor.[String] & "<br>" & vbCr & vbLf)
theColor = theImage.GetColor(New XPoint(150, 150))
Response.Write("Bottom Left Color is " & theColor.[String] & "<br>" & vbCr & vbLf)
The graphics file and text output that this produces are shown below. Note that the names of colors map onto what might be described as a typical value rather than a 100% saturated value. For instance green is not a 100% saturated green with no other components (this looks rather garish) but a rather more typical green color.
Top Left Color is 86.7,3.1,2.4,0.0
Top Right Color is 0.0,39.2,6.7,0.0
Bottom Left Color is 0.0,0.0,83.1,0.0
Bottom Left Color is 98.8,95.3,2.0,0.0
getcolor.gif