扩展ImageMagickNet

Question

我正在尝试向ImageMagickNet类添加一个自定义函数。它应该使用ImageMagick.NET项目中的IsSimilarImage magick方法，但是我不知道是否必须通过Magick++路由这个方法，因为.NET端可用的任何功能都源自Magick++。

Answer 1

这是相当古老的，但因为它是没有回答的，这是。

请注意，我没有研究过ImageMagick库，因此以下代码中的任何实现细节都只是一个示例。用正确的实现替换垃圾。假设它导出的是有效的.NET对象，它的工作方式如下：

' Put your extension methods or properties in a clearly labeled module file, on its own within your project
Module ImageMagickNetExtensions

    ' Define an extension method by using the ExtensionAttribute, and make the first argument
    ' for the method the type that you wish to extend. This will serve as a reference to the extended
    ' instance, so that you can reference other methods and properties within your extension code.
    <Extension()> _
    Public Function SomeExtensionFunction(ByVal imn As ImageMagickNet, ByVal filename As String) As Boolean
        Return imn.IsSimilarImage(filename)
    End Function

End Module

Class SomeClass
    ' To use your extension method within your project containing the extension module, simply
    ' call it on any valid instance of the type you have extended. The compiler will call your code
    ' whenever it sees reference to it, passing a reference to your extended instance.
    Private imn As New ImageMagickNet

    Private Sub DoSomething()
        If imn.SomeExtensionFunction("c:\someimage.jpg") Then
            ...
        End If
    End Sub
End Class