64 lines
2.1 KiB
MQL5
64 lines
2.1 KiB
MQL5
|
//+------------------------------------------------------------------+
|
||
|
|
//| ScriptRemove.mq5 |
|
||
|
|
//| Copyright 2021, MetaQuotes Ltd. |
|
||
|
|
//| https://www.mql5.com |
|
||
|
|
//+------------------------------------------------------------------+
|
||
|
|
|
||
|
|
//+------------------------------------------------------------------+
|
||
|
|
//| Example of a class which can produce errors inside |
|
||
|
|
//+------------------------------------------------------------------+
|
||
|
|
class ProblemSource
|
||
|
|
{
|
||
|
|
public:
|
||
|
|
ProblemSource()
|
||
|
|
{
|
||
|
|
// emulate failure during object creation, for example,
|
||
|
|
// during some resource acquiring such as a file, etc.
|
||
|
|
if(rand() > 20000)
|
||
|
|
{
|
||
|
|
ExpertRemove(); // set _StopFlag to true
|
||
|
|
}
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
ProblemSource global; // this object may fail
|
||
|
|
|
||
|
|
//+------------------------------------------------------------------+
|
||
|
|
//| Worker function stub |
|
||
|
|
//+------------------------------------------------------------------+
|
||
|
|
void SubFunction()
|
||
|
|
{
|
||
|
|
ProblemSource local; // this object may fail
|
||
|
|
// emulate some work (with a valid object only)
|
||
|
|
Sleep(1000);
|
||
|
|
}
|
||
|
|
|
||
|
|
//+------------------------------------------------------------------+
|
||
|
|
//| Script program start function |
|
||
|
|
//+------------------------------------------------------------------+
|
||
|
|
void OnStart()
|
||
|
|
{
|
||
|
|
int count = 0;
|
||
|
|
// loop until stopped by user or programmatically
|
||
|
|
while(!IsStopped())
|
||
|
|
{
|
||
|
|
// we could use 'break' to exit the loop, but sometimes
|
||
|
|
// the condition for breaking is burried deep inside nested calls,
|
||
|
|
// then setting the stop flag to true will also work in deferred manner
|
||
|
|
// on the next time when while condition is checked
|
||
|
|
|
||
|
|
SubFunction();
|
||
|
|
Print(++count);
|
||
|
|
}
|
||
|
|
/*
|
||
|
|
example output
|
||
|
|
|
||
|
|
1
|
||
|
|
2
|
||
|
|
3
|
||
|
|
ExpertRemove() function called
|
||
|
|
4
|
||
|
|
*/
|
||
|
|
}
|
||
|
|
//+------------------------------------------------------------------+
|