谁做过Twain开发
操作外围设备去取像,Twain接口如何设置dpi和图片大小等参数.
我试了不行.
TwCap[] tCap = new TwCap[3];
tCap[0] = TwCap.XferCount;
tCap[1] = TwCap.ICAP_XRESOLUTION;
tCap[2] = TwCap.ICAP_YRESOLUTION;
short[] sval = new short[3];
sval[0]=(short)1;
sval[1]=(short)200;
sval[2]=(short)200;
TwCapability cap = new TwCapability(tCap, sval);
//设置DS参数
rc = DScap(appid, srcds, TwDG.Control, TwDAT.Capability, TwMSG.Set, cap);
TwImageInfo iinf = new TwImageInfo();
iinf.XResolution = 200;
iinf.YResolution = 200;
rc = DSiinf(appid, srcds, TwDG.Image, TwDAT.ImageInfo, TwMSG.Get, iinf);
if (rc != TwRC.Success)
{
CloseSrc();
return pics;
}
//真正传输图像,,写入hbitmap指向的结构
rc = DSixfer(appid, srcds, TwDG.Image, TwDAT.ImageNativeXfer, TwMSG.Get, ref hbitmap);
if (rc != TwRC.XferDone)
{
CloseSrc();
return pics;
}
//结束传输
rc = DSpxfer(appid, srcds, TwDG.Control, TwDAT.PendingXfers, TwMSG.EndXfer, pxfr);
if (rc != TwRC.Success)
{
CloseSrc();
return pics;
}