Halcon10.0 以後，當鼠標離開窗口時，get_mposition算子將異常，需加異常捕獲方能正常運行。
Halcon的異常處理方式轉自：http://k594081130.blog.163.com/blog/static/21835901320141217371386/
第一種、面向對象的方法（ Error handling using HException and try/catch）
在C:\Users\Public\Documents\MVTec\HALCON-10.0\examples\cpp\source可以找到example_errorhandling.cpp
首先聲明
// exception handler
void MyHalconExceptionHandler(const Halcon::HException& except)
{
throw except;
}
然後定義一個函數
Herror TryReadImage(Halcon::HImage &image, const char *filename)
{
using namespace Halcon;
Herror error_num;
try
{
cout << endl << "Trying to read '" << filename << "' ... ";
image = HImage::ReadImage(filename);
}
catch (HException &except)
{
error_num = except.err;
cout << endl << except.message << endl;
return error_num;
}
// success
cout << "succeeded!" << endl;
return H_MSG_TRUE;
}
注意在調用的過程中首先要exception“句柄”：
// install the exception handler
HException::InstallHHandler(&MyHalconExceptionHandler);
最後調用TryReadImage
第二種、程序法
在例程(Ctrl+E)——應用範圍——一般——搜索“error”有一個dev_set_check的例子如下：
// Local iconic variables
Hobject Image;
// Local control variables
Herror Error;
HTuple WindowHandle, FileName, ReadError;
if (HDevWindowStack::IsOpen())
close_window(HDevWindowStack::Pop());
set_window_attr("background_color","black");
open_window(0,0,512,512,0,"","",&WindowHandle);
HDevWindowStack::Push(WindowHandle);
// Error variable 'Error' activated
set_check("~give_error");
FileName = "wrong_name";
Error = read_image(&Image, FileName);
ReadError = (int)Error;
set_check("give_error");
if (0 != (ReadError!=2))
{
Error = write_string(WindowHandle, "wrong file name: "+FileName);
}
//Now the program will stop with an exception（注意 Error = read_image(&Image, FileName);要在set_check前面纔有效。）
Error = read_image(&Image, FileName);
//Please note that some tuple operations have no return value. Then, the described approach leads to a
memory leak. Please use the object-oriented approach instead.
//請注意，某些元組操作沒有返回值。然後，所描述的方法導致一個內存泄漏。請用面向對象的方法來代替。
舉一個實時顯示圖像窗口中鼠標所在位置的像素亮度的例子
read_image (Image, 'fabrik')
while (1)
dev_set_check ('~give_error')
try
dev_display (Image)
get_mposition (3600, Row, Column, Button)
*在halcon10.0後當鼠標離開圖像窗口後，get_mposition算子出現異常。必須要有異常處理才能運行正常！
get_grayval (Image, Row, Column, Grayval)
set_tposition (3600, 24, 24)
write_string (3600, 'Row='+Row)
set_tposition (3600, 64, 24)
write_string (3600, 'Column =' +Column)
set_tposition (3600, 104, 24)
write_string (3600, 'Grayval =' +Grayval)
catch (Exception)
set_tposition (3600, 24, 24)
write_string (3600, Exception)
endtry
dev_set_check ('give_error')
wait_seconds (0.1)
endwhile
