如何在吐温中扫描多个文件

Question

我用Python开发了一个应用程序。我已将丢失的文档放入扫描仪。因此，按下按钮时，我想扫描所有这些文档并保存到程序中。

import twain
sm = twain.SourceManager(0)
ss = sm.OpenSource()
for i in range(3):  //for ex. 3 documents in the scanner device
   ss.RequestAcquire(0,0)
   rv = ss.XferImageNatively()
   if rv:
       (handle, count) = rv
       twain.DIBToBMFile(handle, '{i}.bmp'.format(i))

按下按钮时，所有文档扫描但无法保存到程序中。我有一个错误twain.excTWCC_SEQERROR.那么我该如何解决这个问题呢？

Answer 1

发送请求后，您必须等到映像准备就绪。因此，您需要根据 TWAIN 模块文档设置事件回调：

SourceManager.SetCallback(pfnCallback)
This method is used to set the callback handler. The callback handler is invoked when the TWAIN source signals our application. It can signal our application to indicate that there is data ready for us or that it wants to shutdown.
The expected events are:
MSG_XFERREADY (0x101) - the data source has data ready
MSG_CLOSEDSREQ (0x0102) - Request for Application. to close DS
MSG_CLOSEDSOK (0x0103) - Tell the Application. to save the state.
MSG_DEVICEEVENT (0X0104) - Event specific to Source

可能的代码更改：

import twain
sm = twain.SourceManager(0)
sm.SetCallback(onTwainEvent)
ss = sm.OpenSource()
index = 0
for i in range(3):  //for ex. 3 documents in the scanner device
   ss.RequestAcquire(0,0)
def onTwainEvent(event):
    if event == twain.MSG_XFERREADY:
        saveImage()
def saveImage():
    rv = ss.XferImageNatively()
    if rv:
        (handle, count) = rv
        twain.DIBToBMFile(handle, '{index}.bmp'.format(index))
        index += 1

你也可以参考皮特温代码。