将图片转换成指定高宽和指定相素的jpg文件

[code=vbscript]'以下代码仅供参考
'将picture1中的图片缩放为picture2的宽度和高度后，保存为文件 d:\001.bmp
option explicit
private declare function stretchblt lib "gdi32" （byval hdc as long, byval x as long, byval y as long, byval nwidth as long, byval nheight as long, byval hsrcdc as long, byval xsrc as long, byval ysrc as long, byval nsrcwidth as long, byval nsrcheight as long, byval dwrop as long) as long
private const srccopy = &hcc0020 ' （dword) dest = source

private sub command1_click（)
        dim rtn as long
        dim hdc1 as long, hdc2 as long
        hdc1 = picture1.hdc
        hdc2 = picture2.hdc
        rtn = stretchblt（hdc2, 0, 0, picture2.scalewidth, picture2.scaleheight, hdc1, 0, 0, picture1.scalewidth, picture1.scaleheight, srccopy)
        savepicture picture2.image, "d:\001.bmp"
        
end sub

private sub form_load（)
        me.scalemode = 3
        picture2.autoredraw = true
        picture1.picture = loadpicture（"f:\资料\my pictures\001.bmp")
end sub

'以下代码仅供参考
'将picture1中的图片缩放为picture2的宽度和高度后，保存为文件 d:\001.bmp
option explicit
private declare function stretchblt lib "gdi32" （byval hdc as long, byval x as long, byval y as long, byval nwidth as long, byval nheight as long, byval hsrcdc as long, byval xsrc as long, byval ysrc as long, byval nsrcwidth as long, byval nsrcheight as long, byval dwrop as long) as long
private declare function setstretchbltmode lib "gdi32" （byval hdc as long, byval nstretchmode as long) as long
private const halftone = 4
private const srccopy = &hcc0020 ' （dword) dest = source

private sub command1_click（)
        dim rtn as long
        dim hdc1 as long, hdc2 as long
        hdc1 = picture1.hdc
        hdc2 = picture2.hdc
        call setstretchbltmode（hdc2, halftone)
        rtn = stretchblt（hdc2, 0, 0, picture2.scalewidth, picture2.scaleheight, hdc1, 0, 0, picture1.scalewidth, picture1.scaleheight, srccopy)
        savepicture picture2.image, "d:\001.bmp"
        
end sub

private sub form_load（)
        me.scalemode = 3
        picture2.autoredraw = true
        picture1.picture = loadpicture（"f:\资料\my pictures\001.bmp")
end sub