2010-06-21 35 views
0

这是我必须处理平滑滚动的代码片段。这里是NSLog的输出:从GetEventParameter获取错误代码

2010-06-21 16:04:10.524 PDFViewWXOSX[80161:a0f] first error: -9870 
2010-06-21 16:04:10.525 PDFViewWXOSX[80161:a0f] second error: 0 
2010-06-21 16:04:10.552 PDFViewWXOSX[80161:a0f] first error: 0 
2010-06-21 16:04:10.553 PDFViewWXOSX[80161:a0f] second error: 0 
2010-06-21 16:04:10.582 PDFViewWXOSX[80161:a0f] first error: 0 
2010-06-21 16:04:10.582 PDFViewWXOSX[80161:a0f] second error: 0 
2010-06-21 16:04:10.588 PDFViewWXOSX[80161:a0f] first error: -9870 
2010-06-21 16:04:10.589 PDFViewWXOSX[80161:a0f] second error: 0 
2010-06-21 16:04:10.652 PDFViewWXOSX[80161:a0f] first error: 0 
2010-06-21 16:04:10.652 PDFViewWXOSX[80161:a0f] second error: 0 
2010-06-21 16:04:10.723 PDFViewWXOSX[80161:a0f] first error: 0 
2010-06-21 16:04:10.723 PDFViewWXOSX[80161:a0f] second error: 0 
  SInt32 scroll_delta_x = 0, scroll_delta_y = 0; 
      OSErr err = noErr; 

      err = GetEventParameter(cEvent, kEventParamMouseWheelSmoothHorizontalDelta, 
            typeSInt32, NULL, sizeof(scroll_delta_x), NULL, 
            &scroll_delta_x); 
      NSLog(@"first error: %d", err); 
      if (err == noErr) { 
       deltaX = scroll_delta_x; 
      } 
      err = noErr; 
      err = GetEventParameter(cEvent, kEventParamMouseWheelSmoothVerticalDelta, 
            typeSInt32, NULL, sizeof(scroll_delta_y), NULL, 
            &scroll_delta_y); 
      NSLog(@"second error: %d", err); 
      if (err == noErr) { 
       deltaY = scroll_delta_y; 
      } 

我找不到有关错误-9870的任何信息。到底是怎么回事?

回答

1

错误-9870是在CarbonEventsCore.h中声明的eventParameterNotFoundErr。对这些事件参数的标题注释说,你应该准备好它们不存在的可能性。