如何在 C++/CLI 中创建 C# 事件处理程序？答案

【问题标题】：How to create C# event handlers in C++/CLI?如何在 C++/CLI 中创建 C# 事件处理程序？
【发布时间】：2013-05-12 05:12:06
【问题描述】：

这是我的代码：

private: System::Void button3_Click(System::Object^  sender, System::EventArgs^  e)
{
    System::Speech::Recognition::SpeechRecognizer ^sr = gcnew System::Speech::Recognition::SpeechRecognizer();

    array<String ^> ^strs = gcnew array<String ^> {"Hello", "World"};

    System::Speech::Recognition::Choices ^colors = gcnew System::Speech::Recognition::Choices();
    colors->Add(strs);

    System::Speech::Recognition::GrammarBuilder ^gb = gcnew System::Speech::Recognition::GrammarBuilder();
    gb->Append(colors);

    System::Speech::Recognition::Grammar ^g = gcnew System::Speech::Recognition::Grammar(gb);
    sr->LoadGrammar(g);

    // System::IntPtr ptr = gcnew System::IntPtr(&sr_SpeechRecognized);
    sr->SpeechRecognized += gcnew System::EventHandler<System::Speech::Recognition::SpeechRecognizedEventArgs>(this,&Form1::sr_SpeechRecognized);
}

void sr_SpeechRecognized(System::Object ^sender, System::Speech::Recognition::SpeechRecognizedEventArgs^ e)
{
 }

此代码产生以下错误

1>------ Build started: Project: SpeechTest, Configuration: Debug Win32 ------
1>  SpeechTest.cpp
1>c:\users\yohan\documents\visual studio 2010\projects\speechtest\speechtest\Form1.h(144): error C3225: generic type argument for 'TEventArgs' cannot be 'System::Speech::Recognition::SpeechRecognizedEventArgs', it must be a value type or a handle to a reference type
1>c:\users\yohan\documents\visual studio 2010\projects\speechtest\speechtest\Form1.h(144): error C3352: 'void SpeechTest::Form1::sr_SpeechRecognized(System::Object ^,System::Speech::Recognition::SpeechRecognizedEventArgs ^)' : the specified function does not match the delegate type 'void (System::Object ^,System::Speech::Recognition::SpeechRecognizedEventArgs)'
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

在这里，一切正常，期待处理程序创建sr->SpeechRecognized += gcnew System::EventHandler<System::Speech::Recognition::SpeechRecognizedEventArgs>(this,&Form1::sr_SpeechRecognized);

如果您注释掉这个处理程序部分，一切都会好起来的。这里Form 表示当前的GUI 表单，由C++/CLI 构建的默认GUI 表单。所有这些代码都在该表单中。我按照我在文章中读到的方式创建了这个处理程序。接下来我可以尝试什么？

【问题讨论】：

标签： c# .net visual-studio-2010 c++-cli speech-recognition

【解决方案1】：

您缺少^。

sr->SpeechRecognized += gcnew System::EventHandler<System::Speech::Recognition::SpeechRecognizedEventArgs^>(this,&Form1::sr_SpeechRecognized);
                                                                                           // right here ^

仔细查看您收到的错误消息，删除了命名空间，并使用换行符使内容对齐。

错误 C3352：“无效 SpeechTest::Form1::sr_SpeechRecognized(Object^,SpeechRecognizedEventArgs^)”：指定的函数与委托类型“void (Object^,SpeechRecognizedEventArgs)”不匹配 ^

您正在尝试为采用 SpeechRecognizedEventArgs 的方法创建一个委托，但您为其提供了采用 SpeechRecognizedEventArgs^ 的方法的名称。

【讨论】：