Reference

COM interfaces are declared using an automation language. Because that language is neutral to the entire set of programming languages that support automation-enabled components, the syntax details are left apart.

Because of this, a VB developer for instance may find it rather difficult to get the most of those interfaces because they are not expressed with the VB language syntax.

As a matter of simplifying the readability and the use of those interfaces, below are simple rules that apply according to your preferred programming language.

• when a method declaration is neither prefixed by propput not propget, then it's a method callable using the regular VB function call mechanism (parenthesis must be used if there is more than one parameter)
• when a method declaration is prefixed with propget, then it behaves like a regular VB property
• when a method declaration is prefixed with propput and has only one parameter, then it behaves like a regular VB property
• when a method declaration is prefixed with propput and has more than one parameters, then it behaves like an extended VB property. To use it, parenthesis must enclose the n-1 first parameters as in myproperty(param_1, param_2, ...) = param_n. If you read HRESULT Label([in]int row, [in]int col, [in]BSTR label); then you should write Label(row, col) = label;
• a parameter prefixed with [in] is an input parameter. It must be passed in, unless it is explicitely declared [optional]
• a parameter prefixed with [out, retval] is a return value. If you see HRESULT NewStyle([out, retval] IXlsStyle** style); then you should write code like :

  Dim style As IXlsStyle
  Set style = NewStyle
  

• the BSTR type is a simple String
• intellisense is your friend. As you type code, you should see drop downs. If you don't, there is a problem somewhere in your code syntax or referenced objects (or the Excel generator type-library is not yet referenced. See getstarted for more info).

• when a method declaration is neither prefixed by propput nor propget, then it's a method callable using the regular C# method call mechanism
• when a method declaration is prefixed with propget, then it behaves like a regular C# property. The get_ prefix must be used. For instance, if you read [propget] Label() then you should write get_Label()
• when a method declaration is prefixed with propput and has only one parameter, then it behaves like a regular C# property
• when a method declaration is prefixed with propput and has more than one parameters, then it behaves like a regular C# method with a set_ prefix. If you read HRESULT Label([in]int row, [in]int col, [in]BSTR label); then you should write set_Label(row, col, label);
• If you are getting the value of more than one property in a single statement, or if you traverse properties, then you must add parenthesis suffixes to properties in between. For instance, if you want to change the background color of a style, write style.Pattern.BackgroundColor = 0xFFFFBB;
• a parameter prefixed with [in] is an input parameter. It must be passed in, unless it is explicitely declared [optional]
• a parameter prefixed with [out, retval] is a return value. If you see HRESULT NewStyle([out, retval] IXlsStyle** style); then you should write IXlsStyle style = wksht.NewStyle();
• the BSTR type is a simple String
• enumerated types are unfolded using the regular intellisense mechanism. For instance, to get the enumeration for the enumColorPalette type, just type xlsgen.enumColorPalette. and let intellisense drive you
• intellisense is your friend. As you type code, you should see drop downs. If you don't, there is a problem somewhere (or the Excel generator assembly is not yet referenced. See .NET integration for more info).

If you use raw C/C++ code then you can skip this section. The rules apply to a C/C++ developer using smart pointers.

• Because of nature of smart pointers, to traverse methods and properties, the pointer notation must be used
• when a method declaration is neither prefixed by propput nor propget, then it's a method callable using the regular C/C++ method call mechanism
• when a method declaration is prefixed with propget, then it behaves like a regular C/C++ property.
• when a method declaration is prefixed with propput and has only one parameter, then it behaves like a regular C/C++ property
• when a method declaration is prefixed with propput and has more than one parameters, then it behaves like an extended C/C++ property. Use closed brackets to enclose the first n-1 parameters. If you read HRESULT Label([in]int row, [in]int col, [in]BSTR label); then you should write Label[row][col] = label;
• If you are getting the value of more than one property in a single statement, or if you traverse properties, then you must add parenthesis suffixes to properties in between. For instance, if you want to change the background color of a style, write style->Pattern->BackgroundColor = 0xFFFFBB;
• a parameter prefixed with [in] is an input parameter. It must be passed in, unless it is explicitely declared [optional]
• a parameter prefixed with [out, retval] is a return value. If you see HRESULT NewStyle([out, retval] IXlsStyle** style); then you should write xlsgen::IXlsStylePtr style = wksht->NewStyle();
• the BSTR type is a windows-specific unicode string. If you are using a constant string then prefix it with L as, in L"hello world!". If the string is dynamically constructed and is initially not unicode, then you must convert it using either the _bstr_t helper, or the WIN32 API function call ::MultiByteToWideChar(...).
• intellisense is your friend. As you type code, you should see drop downs. If you don't, there is a problem somewhere (or the Excel generator type-library is not yet referenced. See getstarted for more info).

All HRESULT error values returned by xlsgen are standard Win32 error values (see winerror.h from the Platform SDK) : a value of 0 means OK, a non-zero value means an error occured. xlsgen however creates five additional HRESULT values :