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www.expresso.com, or search for Expresso on this site. It's a program that helps you build and test regex. Also, the regex book from O'Reiley is pretty awesome.
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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But there is RegEx in general and then there is .NET's flavor of RegEx. Are you recommending the O'Reilly book for .NET?
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The O'Reilly book covers the different flavours in depth.
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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+1 for http://regexlib.com[^]
[ My Blog] "Visual studio desperately needs some performance improvements. It is sometimes almost as slow as eclipse." - Rüdiger Klaehn "Real men use mspaint for writing code and notepad for designing graphics." - Anna-Jayne Metcalfe
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If I understand you correctly, it would be a simple case of creating a regex string of something like "^(?<mymatch>.*)"+ sMyTerminatorString. Then check the matches for mymatch (or whatever you name it).
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Look into RegexOptions.MultiLine to change whether "." matches newlines as well...
myRegex = new Regex("^.*?(?=myStringThatDelimitsTheEndOfTheMatch)");
Match m = myRegex.Match(sampleString);
if (m.Success) {
m.Value; // this returns only the part of the match
// that occured prior to your delimiting string
}
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I have the following function:
public bool getOperatorResult<T>(string operatorType, T operandA, T operandB)
{
if (typeof(T) == typeof(bool))
{
System.Object obj = operandA;
bool a = (bool) obj;
obj = operandB;
bool b = (bool) obj;
switch (operatorType)
{
case "or":
return (a || b);
case "and":
return (a && b);
case "equal":
return (a == b);
case "notequal":
return (a != b);
default:
return false;
}
}
else if ((typeof(T) == typeof(int)) || (typeof(T) == typeof(double)))
{
}
}
This code works but just does not look right to me. Also in the second part where I look for numbers, I don't know how I can cast to either int or double. Any ideas
If I try to directly put in:
switch (operatorType)
{
case "lessthan":
return (operandA < operandB);
case "morethan":
return (operandA > operandB);
case "lessthanequalto":
return (operandA <= operandB);
case "morethanequalto":
return (operandA >= operandB);
case "equal":
return (operandA == operandB);
case "notequal":
return (operandA != operandB);
default:
return false;
}
I get compiler errors:
Operator '<' cannot be applied to operands of type 'T' and 'T'
.....
.....
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Can you constrain your accepted types in order to enforce that they are comparable ?
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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I need to accept bool, string, and numbers (int's and doubles).
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They all implement IComparable, don't they? Just use the where T:IComparable constrain in your generic method. Or perhaps use IComparable<T>.
[ My Blog] "Visual studio desperately needs some performance improvements. It is sometimes almost as slow as eclipse." - Rüdiger Klaehn "Real men use mspaint for writing code and notepad for designing graphics." - Anna-Jayne Metcalfe
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Why do you use generics at all?
Wouldn't it just be simpler to do something like that:
public bool GetOperatorResult(string operator, bool a, bool b)
{
}
public bool GetOperatorResult(string operator, int a, int b)
{
}
and let the runtime decide which overload should be called?
-^-^-^-^-^-
no risk no funk ................... please vote ------>
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I did think about this but I would have to create a function that does the same thing for every different type of number (int, double, long, etc....). Is there a way to get around this?
Also, I want to be able to pass in operands of type Object.
Thanks in advance.
-- modified at 11:42 Tuesday 4th September, 2007
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How about if I created a function which takes operands of type Object and then calls other overloaded functions:
public bool getOperatorResult(string operatorType, System.Object operandA, System.Object operandB)
{
if (operandA is bool)
{
return getOperatorResult(operatorType, (bool)operandA, (bool)operandB);
}
else if (operandA is double)
{
return getOperatorResult(operatorType, (double)operandA, (double)operandB);
}
else if (operandA is int)
{
return getOperatorResult(operatorType, (int)operandA, (int)operandB);
}
else if (operandA is long)
{
return getOperatorResult(operatorType, (long)operandA, (long)operandB);
}
else if (operandA is string)
{
return getOperatorResult(operatorType, (string)operandA, (string)operandB);
}
else
{
return false;
}
}
public bool getOperatorResult(string operatorType, bool operandA, bool operandB)
{
switch (operatorType)
{
case "or":
return (operandA || operandB);
case "and":
return (operandA && operandB);
case "equal":
return (operandA == operandB);
case "notequal":
return (operandA != operandB);
default:
return false;
}
}
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This is, at a minimum, not performant, as all your types are not objects, and would have to be boxed and unboxed.
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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for boolean operators such as ^, &, |, &&, and ||, just use a simple switch. Then, if either the type of object is not bool OR if the operator is not one of the preceding, then see if the object implements icomparable. If so (which int and double both do), then return one of the following (you could even check first to see if the comparison is EQUAL or NOTEQUAL, then use .Equals which all objects expose)
public bool compare(object A, object B, comparison comp) {
IComparable ic = A as IComparable;
object other = B;
if (ic == null) {
ic = B as IComparable;
other = A;
comp = SwitchComparison(comp); // simple function that changes
// <= to >=, < to >, and vice versa
}
// check if ic is null... if so, do whatever you think is appropriate
switch (comp) {
case EQUALS:
return ic.CompareTo(other) == 0;
case NOTEQUALS:
return ic.CompareTo(other) != 0;
case GT:
return ic.CompareTo(other) > 0;
...
}
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Anyone know how to deserialize a file, but not load the whole thing in to memory?
Sort of like using a Hashtable, jumping to a point within the file, modifying the data and then closing. Rather than, opening the whole thing up, then rewriting the whole file over and over again.
Thanks
Jeremy  )
-- modified at 11:45 Tuesday 4th September, 2007
I think I may have found what I been looking for, it appears Memorystream might be what im looking for, anyone have any experience with this?
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jblouir wrote: jumping to a point within the file, modifying the data and then closing. Rather than, opening the whole thing up, then rewriting the whole file over and over again.
Your talking about something like ISAM which is completely different than serialization.
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Awesome, thanks for that. Looking in to it now. )
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Hi,
I have a DLL written in C.
I would like to import it in C#(Visual Studio 2005).
How can I do that?
Thanks in advance,
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you can't. You have to write p/invoke signatures that allow you to call methods on the dll, but you can't import it the way you can a COM or managed dll file.
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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thanks,
can you explain please how to write p/invoke signatures .
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You use dllimport, as the other poster said, and then you write a signature that matches the method. www.pinvoke.net[^] has lots of examples, it's probably a great place to start.
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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Hello,
I am currently working on an app that needs the ability to inquire about capabilities of scanners.
I am using the definitions of this project. The problem that appears here is the use of unmanaged library twain_32.dll. All methods imported with dllimport work fine except the DSCap(...) method returns failure code when inquiring about capabilities.
The method DSCap should set the TwCapability variable that is passed with. This TwCapability is defined in the original header file of the twain_32.dll as follows:
typedef struct {
TW_UINT16 Cap;
TW_UINT16 ConType;
TW_HANDLE hContainer;
} TW_CAPABILITY, FAR * pTW_CAPABILITY;
where TW_UINT16 is defined as "typedef short TW_INT16, FAR *pTW_INT16;"
and TW_HANDLE is defined as "typedef HANDLE TW_HANDLE;"
"ConType" gives information about the type of the container that holds the capabilities information and "hContainer" is the pointer to the real capabilities information data.
This TW_CAPABILITY struct is defined in the c# code as follows:
[StructLayout(LayoutKind.Sequential, Pack = 2)]
internal class TwCapability
{
public TwCapability(TwCap cap)
{
Cap = (short)cap;
ConType = -1;
}
~TwCapability()
{
if (hContainer != IntPtr.Zero)
Twain.GlobalFree(hContainer);
}
public short Cap;
public short ConType;
public IntPtr hContainer;
}
To make things easier for you this is the "step by step guide" of how to inquire scanner capabilities from the official TWAINSpec.pdf taken from www.twain.org:
Step 1:
Application allocates a TW_CAPABILITY structure and fills its fields as follows:
• Cap = the CAP_ or ICAP_ name for the capability it is interested in
• ConType = TWON_DONTCARE16
• hContainer = NULL
Step 2:
Application uses the TW_CAPABILITY structure in a DG_CONTROL /
DAT_CAPABILITY / MSG_GET operation.
Step 3:
The Source examines the Cap field to see if it supports the capability. If it does, it creates
information for the application. In either case, it sets its Return Code appropriately.
Step 4:
Application examines the Return Code, and maybe the Condition Code, from the
operation.
If TWRC_SUCCESS then the Source does support the capability and
• The ConType field was filled by the Source with a container identifier
(TWON_ARRAY, TWON_ENUMERATION, TWON_ONEVALUE, or
TWON_RANGE)
• The Source allocated a container structure of ConType and referenced the
hContainer field to this structure. It then filled the container with values
describing the capability’s Current Value, Default Value, and Available Values.
Based on the type of container and its contents (whose type is indicated by it ItemType
field), the application can read the values. The application must deallocate the
container.
If TWRC_FAILURE and TWCC_CAPUNSUPPORTED
• Source does not support this capability
This is how I try inquiring about the caps:
public void GetCapabilities()
{
TwRC rc;
TwCapability twCap = new TwCapability(TwCap.XferCount);
rc = DScap(appid, srcds, TwDG.Control, TwDAT.Capability, TwMSG.Get, twCap);
if (rc == TwRC.Success)
{
MessageBox.Show("worked!");
}
else MessageBox.Show("not!");
}
I always get TWRC_FAILURE in return, though XFERCOUNT must be supported by every scanner.
I suspect the hContainer variable to be the problem, but I am new to c# and interops.
This is the dllimport of the method:
[DllImport("twain_32.dll", EntryPoint = "#1")]
private static extern TwRC DScap([In, Out] TwIdentity origin, [In] TwIdentity dest, TwDG dg, TwDAT dat, TwMSG msg, [In, Out] TwCapability capa);
I know this is a lot of information, but I hope someone has already worked with TWAIN under .net and can help me fix this problem.
Thx in advance
Dominik
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