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  • Displaying a PNG image
  • Transparent image in PNG format
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Stored procedures
Saves an image:
  • in a PNG file.
  • in memory.
This image corresponds to the image contained in one of the following elements:
  • in an Image control.
  • in a variable of type Image.
  • in a Bar Code control.
  • in a Web Camera control.
Remarks:
  • Only the visible part of the Image control is saved.
  • The border of the Image control (if it exists) is also saved.
    Reminder: The border of the Image control is defined in the "Style" tab of the description window of control.
  • This function can only be used to save the images for screen resolutions up to 32 bits.
  • This function cannot be used with the Image controls found in the reports.
// Saves the image found in "IMG_ImageDrawing" in "C:\Documents\Image.PNG"
ResSave = dSaveImagePNG(IMG_ImageDrawing, "C:\Documents\Image.PNG")
// Saves in memory the image found in "IMG_ImageDrawing"
ResSave = dSaveImagePNG(IMG_ImageDrawing, inMemory)
Syntax
Reports and Queries

Saving an image in a PNG file Hide the details

<Result> = dSaveImagePNG(<Image> , <File name> [, <Transparency color>])
<Result>: Boolean
  • True if the image was saved,
  • False otherwise. To get more details on the error, use ErrorInfo with the errMessage constant.
<Image>: Name of the Image control or variable
  • Name of the Image, Bar Code or Web Camera control to be saved. Image controls in a report cannot be used.
  • Name of the Image variable to be used.
<File name>: Character string
Name and full (or relative) path of PNG file. A UNC path can be used. The file extension is optional.
Caution:
  • The destination directory must exist in order for the image to be saved.
  • The existence of the PNG file is not checked. This file is automatically overwritten if it already exists.
<Transparency color>: Optional integer
Color that will be considered as being transparent in the image. This color can correspond to:If this parameter is not specified, the generated image is not transparent.

Saving an image in memory Hide the details

<Result> = dSaveImagePNG(<Image> , <inMemory> [, <Transparency color>])
<Result>: Buffer
Byte string containing the image in PNG format.
Then, this byte string can be assigned to an Image control, saved in a file (fSaveText), sent via a network (with the Socket functions), ...
<Image>: Name of the Image control or variable
  • Name of the Image, Bar Code or Web Camera control to be used. Image controls in a report cannot be used.
  • Name of the Image variable to be used.
<inMemory>: Constant
inMemory: Constant used to save an image in memory.
<Transparency color>: Optional integer
Color that will be considered as being transparent in the image. This color can correspond to:If this parameter is not specified, the generated image is not transparent.
Remarks

Displaying a PNG image

Caution: If the image in PNG format is semi-transparent, the display of the image is slower.

Transparent image in PNG format

To save a transparent image in PNG format, the Image control must be filled with the transparent color beforehand.
Example used to draw a transparent line and to save it in PNG format:
dStartDrawing(IMG_Image1, dWithOpacity)
dChangeMode(drawDefault)
FOR nI = 0 _TO_ IMG_Image1..Width
FOR nJ = 0 _TO_ IMG_Image1..Height
 dPoint(nI, nJ, RGB(255,255,255), 0)
END
END
dPen(RGB(100, 020, 200), 0,10, 100)
dLine(10, 10, 100, 10)
dSaveImagePNG(IMG_Image1, CompleteDir(fExeDir()) + "img.png")
Component: wd290pnt.dll
Minimum version required
  • Version 9
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Last update: 01/18/2024

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