Form, Picture, etc. in VB have a attribute associated with Scale, and the scale property is actually used to implement coordinate systems for customize these containers. And scaletop, scaleleft, scalewidth, scaleheight, etc., the following brief introduction.
The default coordinate system is the coordinates of the upper left corner of the container (0, 0), the lower right corner coordinate, in order to define the coordinate system in order to define the coordinate system according to their needs, then the scale related property is used.
Set the coordinates in the upper left corner by setting Scaleleft and Scaletop. For example, if we need to let the Picmain's upper left corner coordinate is (-100, 100), you can do this:
Picmain.scaleleft = -100
Picmain.scaletop = 100
Generally we determine the coordinates in the lower right corner of the container, the specific calculation method is like this, if the coordinates in the lower right corner are (100, -100), SCALEWIDTH = 100 - Scaleleft = 200, scaleheight = -100-scaletop = -200,
Picmain.scaleWidth = 200
Picmain.scaleHeight = -200
Such a common coordinate system in a math is built.
