Sep 29, 2010 web resources about convert olevariant to string embarcadero. Reflection with idispatchbased com objects codeproject. Object can be exposed to unmanaged code as one of the following types. Converting strings and numbers to currency, and then to string and number again. Tobytes for a happy json outcome the following function will take any delphi json object and convert it to a string. A letter is stored in a single character variable type, such as char, and words and sentences stored in string types, such. But when i compile my sistem i have no idea of how script the user will use, and what functions he will create and what parameters this functions can have.
Then i call the getidsofnamesinvoke function of idispatch to execute the function. It can ask for the execution of a method, passing its name in a string, in a way. If guidtostring succeeds it returns a string for the requested guid. The datetimetostr function converts a tdatetime value datetime into a formatted date and time string. Toint32array is used to convert delphi integer array to. Convert string to integer using arguments from command line. Outofprocess automation servers automation in delphi com. Vstring is actually a string type, but delphi does not let you store a string in a.
As i stated earlier, you can assign a widestring directly to a string, and vice versa. The formatting string or array of strings provides the desired formatting of the double value. By default, with no parameters, it is equivalent to tostring g general formatting is carried. Convert a string to ascii codes and then back to string again.
Version 2 of this function is for use within threads. Oct 18, 2007 find answers to converting apis filetime to delphi s tdatetime from the expert community at experts exchange. If the index is not a string, it is assumed to be an integer although an exception. No conversion errors are generated bad conversions simply result in the default being returned related commands. This way, the appropriate idispatch method that performs latebound execution invoke. If a decimal point appears in floatstring, then it must match the current decimalseparator value. Integer, single, double, currency, tdatetime, widestring, idispatch, scode. I have a form where the tester can type a address in the format 0c00 or whatever. The inttostr function converts an integer number or int64 bignumber into a string. Tstringlist, one still needs to define the string associated with the object, so there will be some equivalent of a case statement listing all of the objects and the associated string. Which makes sense in this situation because lastlogontimestamp. You would have to write a parser for such formats yourself.
This parameter contains a fingerprint template which is referenced as an object in vb. You should remember from chapter 2 that inprocess servers execute in the same address space as the client application. When nil is assigned to a pointer, the pointer doesnt reference anything. Find answers to converting apis filetime to delphis tdatetime from the expert community at experts exchange. The tostring method concerts the current single value into a string representation. Web resources about convert olevariant to string lphi. Consequently we will use delphis type library editor to create a suitable type library that defines our new interface. The strtofloat function converts a number string, floatstring such as 123.
Variant type 9 vardispatch represents a com idispatch object interface. Also remove any calling conventions, inno setup assumes. This class implements the methods of idispatch and so saves us from having to do this ourselves. I am using a com component that has a variable that is in olevariant format. The functions available in the delphi rtl cannot convert strings containing month names, whether they are abbreviated or not. The strtointdef function converts an integer string, integerstring such as 123 into an integer value, with a default if the conversion fails. Delphi record to string conversion example, using operator. The compiler will handle everything for you, as widestring and string are both managed types that the compiler knows how to convert between, and free when they go out of scope.
This doesnt sound logical, given that the convert method used in. However, tautointfobject needs a type library to work with. Reference to an automation object an idispatch interface pointer. For delphi 20009 and later use tsyscharset instead of tcharset and replace all occurrences of string with ansistring. Find answers to convert cstring to idispatch from the expert community at experts exchange. How to incorporate simple scripting capabilities into delphi. Delphi presents, for example, an empty dynamic array or a long string as a nil pointer. One of the methods, according to the idl, takes an idispatch as a parameter and the documentation and samples for this method claim that you can pass either a string which is the progid of an object that will be created and used by the control or an idispatch to an object that has already been created.
Faq topic how do i convert a number into a string with exactly 2 decimal places. Delphi may not be the most popular programming language out there, but we have a lot of great delphi articles here for those diehard fanatics. Outofprocess automation servers automation in delphi. While hydras base library provides implementations for the most general tasks involved while working with plugins for example embedding a visual plugin into your form, most nontrivial applications will need some applicationspecific communication between hosts and plugins. Converting group of strings field names to another strings. Then i have two buttons read from that address and write to that address. It supports integer, floating point, and scientific exponent formats. In this selection excerpted from delphi com programming, author eric. The idispatch interface exposes a number of methods for automation clients that require latebinding such as scripting languages.
Im trying to develop an activexdll which can be used to import data from a server over the network via a special protocol. These can be used to store and display such things as user details, screen titles and so on. Help how do i convert a string to an object name delphi. The following code converts strings into character sets and viceversa. I know i should assign the parameter of type idispatch to a variable declared as a olevariant, but im struggling to extract the data inside.
It might prove useful to call a method, described as string, on an interface. Converts unicode string to ansi string using specified code page. This type library can then be converted by a specific tool such as delphi into. Briefly, the data types that are automation compatible are smallint, integer, single, double, currency, tdatetime, widestring, idispatch, scode, wordbool, olevariant, iunknown, shortint, and byte. Like many other languages, such as vba and java, delphi allows you to store letters, words, and sentences in single variables. Convert strings to character sets and vice versa the following code converts strings into character sets and viceversa. Java comunicaction with delphi corba server and orb corba for j2me windows ce. The real idispatch also has an invoke method next, but we dont need it. Vunknown is actually an iunknown interface, and vdispatch is an idispatch. Only com interop supports marshaling for object types. An easy way to do this is to derive the new class from tautointfobject. The ihtmldocument2 interface inherits from the idispatch interface. The strtoint function converts an integer string, integerstring such as 123 into an integer.
Systemolevariant is a special descendant of the variant class that is used to represent com interfaces or data that is passed over a com interface. Find answers to delphi convert string to date from the expert community at experts exchange. Tostring is broken, and how to fix it november 1, 20 bugs, computing, delphi, development, suggestions, unicode marc durdin as per several qc reports, data. The date and time formats are also affected by the dateseparator and timeseparator values. I am a self taught dehphi, pascal programer an need some help. I need to convert this format into a stringblobanything so i can save it into a db and then convert it back into the olevariant format for recompare. Delphi record to string conversion example, using operator overload. When creating an automation object using the delphi wizard, one of the available choices allows. There are two support functions to initialize idispatch based com automation. A letter is stored in a single character variable type, such as char, and words and sentences stored in string types, such as string. The first automation server were going to develop is a simple inprocess automation server. Is there a way to convert or copy a string to a tstring.
Im writing a test application that talks to a hardware unit. Delphi equivalent in the c world or schemelisp world. The real work of gathering and translating the type information for. This idispatch can be used to call any function on the script.
If you copy the interface definition from any existing delphi source code, remove the brackets around the interface guid string. Delphi source code, remove the brackets around the interface guid string. Stringtoguid can be used to convert the string representation of a guid into a real guid. Use olecheck to check the return values of any method you call. Note that for delphi 7 and possibly other versions of delphi, you may omit the 0 before the x for hexadecimal values. Thanks for the replies folks, i used the trim function which thiagoblimeira instead of the string replace just to make my code look cleaner. See these two formatting variables for more details. Convert cstring to idispatch solutions experts exchange. Stringtoguid can be used to convert the string representation of a guid into a real.
Jan 07, 20 preservesig int getdispidref guid riid, ref string name, int namecount, int lcid, out int dispid. Formats a measurement and its conversion unit into a humanreadable string. It is possible to get the abbreviated and full names for the months from windows, for the current locale. I hope that this example could by explanatory enougth. Inprocess automation servers automation in delphi com. You can cast any variant to tvardata to examine the internal workings of the. Nil is a special constant that can be assigned to any pointer. I send to the unit a word indicating the address i want to read or write but, how to. Delphi convert string to date solutions experts exchange.
Systemolevariant inherits from variant as a protected class so that it can prevent operations on ansistring objects, which are not compatible with com the syntax for using systemolevariant is the same as that for using the variant class. Net is handled by the typetotypeinfomarshaler on idispatchinfo. Calling idispatch directly delphi tips cjc delphi cool delphi tips. Apr 18, 2019 nil is a special constant that can be assigned to any pointer. A pascal string is layed out with the length of the string in character0 with the actual characters starting at character1 this also means than ordastring1 gives you the length. Implement the idispatch interface in comenabled classes that have to act as automation controllers. Guidtostring converts a guid into a string of printable characters. When you assign a variant that contains custom data such as a delphi string, or one of the new custom variant types to an olevariant, the runtime library tries to convert the variant into one of the olevariant standard data types such as a delphi string converts to an ole bstr string.
Which means, for all intents and purposes, tjsonanything. Thanks geert for the tip, sorry im new to delphi 2 months, still learning my way round. Preservesig int getdispidref guid riid, ref string name, int namecount, int lcid, out int dispid. Windows that contain html documents always have valid document objects. Web resources about converting string to tdatetime lphi. In chapter 2, i discussed the need for marshaling in outofprocess com servers. I need to convert this format into a string blobanything so i can save it into a db and then convert it back into the olevariant format for recompare. Use widestring instead of string in dispinterfaces dynamic programming. Getting the functions and parameters list from a idispatch.