TiVCLComponent.GetBytesJPEG
TiVCLComponent See Also
Gets a JPEG encoded image of the component for use in ASP web pages.
function GetBytesJPEG(Compression: Integer; Progressive: Boolean): OleVariant;
Description
Use GetBytesJPEG to get a JPEG encoded image of the component of type
OleVariant (VT_ARRAY | VT_UI1), which is a variant array of unsigned one-byte
characters. JPEG is a lossy-compressed, pixel-based representation of the component.
This function is useful in Microsoft Internet Information Server (IIS Server) ASP
web pages where you wish to display a static graphic of the component on a web
browser. The JPEG format image is compatible with any web browser on any
platform.
Note: If you wish to display dynamic or interactive controls, you will need to
instantiate the component on the end-client web browser. The only drawback to
doing that is that the end-user browser must be Microsoft Internet Explorer
running under a Windows operating system (Intel Processor based). The GetBytesJPEG
function allows you to display static content only.
Compression refers to the quality level of the compression you wish to apply
to the image. A quality of 100 will give a higher quality result than 33.
Valid values are between 0 and 100. With line art type graphics (like computer
screen shots and component images), it is recommended that you leave the
Compression value at 100 for the best results.
Progressive refers to the progressive encoding of the JPEG image. When this
property is TRUE, then the image will be displayed progressively on a web page
as it is downloaded.
Example
Delphi
Value := iComponent.GetBytesJPEG(100, True);
C++ Builder
Value = iComponent->GetBytesJPEG(100, True);
Microsoft IIS Server ASP Page (VBScript, ActiveX version of our controls only)
<%@ Language=VBScript %>
<!--METADATA NAME="iPlotLibrary" TYPE="TypeLib"
UUID="{DA259054-D93B-498C-8C10-DEBD83EF1357}"-->
<%
'Setup Response
Response.Expires = 0
Response.Buffer = True
Response.Clear
'Create ActiveX Control
Set iPlotX1 = Server.CreateObject("iPlotLibrary.iPlotX")
'Set Some Properties
iPlotX1.Width=500
iPlotX1.Height=300
iPlotX1.TitleText = "Test Chart 1"
iPlotX1.ToolBar(0).Visible = False
'Plot Some Random Data
for x = 0 to 100
iPlotX1.Channel(0).AddXY x, sin(x) * 100
next
'Stream JPEG Image
Response.ContentType = "image/jpeg"
Response.BinaryWrite(iPlotX1.GetBytesJPEG(100, TRUE))
'Cleanup
Set iPlotX1 = Nothing
%>
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