使用 wwDotNetBridge 运行 .NET 代码
在 West Wind 的 wwDotNetBridge 的帮助下,你可以轻松访问 VFP 程序中的 .NET 代码。
该白皮书具有的所有细节,但这个简明的例子将有助于说明基本步骤,在运行在 .NET 组件的方法。
请注意,wwDotNetBridge 可以直接访问简单属性,如字符串,整数等。为了访问更复杂的结构,如列表,首先需要使用 wwDotNetBridge 函数 CreateArray 将 .NET 结构转换为 VFP COM 数组(如图所示)这个例子的底部)。
*!* Load WestWind .NET wrapper library (wwdotnetbridge.prg assumed to be in the search path)
IF (!wwDotNetBridge())
RETURN .F.
ENDIF
lowwDotNetBridge = CREATEOBJECT("wwDotNetBridge","V4")
*!* Load .NET Assembly (include full or relative path if necessary)
IF !lowwDotNetBridge.LoadAssembly("SomeDotNetAssembly.dll")
lcAssemblyLoadError = "LoadAssembly error: " + lowwDotNetBridge.cErrorMsg
=MESSAGEBOX(lcAssemblyLoadError, MB_ICONSTOP, "Error")
RETURN .F.
ENDIF
*!* Parameters to pass to class constructor
*!* You can pass up to 5 paramenters to the constructor
lcParameter1 = "StringParameter1"
lcParameter2 = "StringParameter2"
lnParameter3 = 3
lcParameter4 = .NULL.
*!* Get an instance of the assembly class
loAssemblyReference = lowwDotNetBridge.CreateInstance("MyDotNetProject.MyDotNetClass", ;
lcParameter1, lcParameter2, lnParameter3, lcParameter4)
IF lowwDotNetBridge.lError
lcAssemblyLoadError = "An error occurred loading the class: " + lowwDotNetBridge.cErrorMsg
RETURN .F.
ENDIF
*!* Usage Example
*!* This example runs a method that return a boolean
*!* and populates a List<string> (SomeStringList).
*!*
*!* The assembly has a public property named "LastErrorMessage"
*!* with details about any handled exceptions/problems.
IF (!loAssemblyReference.SomePublicMethod())
msg = "There was a problem executing the method:" + CRLF + ;
loAssemblyReference.LastErrorMessage
=MESSAGEBOX(msg, MB_ICONSTOP, "Error")
RETURN .F.
ENDIF
*!* At this point the string list (SomeStringList) should be populated
*!* wwDotNetBridge can convert that list to a VFP COM array (0-based)
laVFPArrayOfStrings = lowwDotNetBridge.CreateArray()
laVFPArrayOfStrings.FromEnumerable(loAssemblyReference.SomeStringList)
FOR x = 0 TO laVFPArrayOfStrings.Count-1
? laVFPArrayOfStrings.Item(x)
ENDFOR