visual-c++ - 如何从消息框获取答案

Question

我复制

if ((MessageBox::Show(
     "Are you sure that you would like to close the form?", 
     "Form Closing", MessageBoxButtons::YesNo, 
     MessageBoxIcon::Question) == DialogResult::No))
  {
     // cancel the closure of the form.
     Application::Exit();
  }

来自 msdn .我在哪里编译这个我有

1>------ Build started: Project: test2, Configuration: Debug Win32 ------ 1> test2.cpp 1>c:\users\kredkołamacz\documents\visual studio 2010\projects\test2\test2\Form1.h(103): error C2039: 'No' : is not a member of 'System::Windows::Forms::Form::DialogResult' 1> c:\users\kredkołamacz\documents\visual studio 2010\projects\test2\test2\Form1.h(16) : see declaration of 'System::Windows::Forms::Form::DialogResult' 1>c:\users\kredkołamacz\documents\visual studio 2010\projects\test2\test2\Form1.h(103): error C2065: 'No' : undeclared identifier ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

怎么了？如何解决这个问题？

Answer 1

我很困惑，但是 DialogResult 的 MSDN 文章在 C++ 示例中提到类型名称应以 :: 为前缀以使其成为非嵌套的。也许试试这个:

if (MessageBox::Show(
     "Are you sure that you would like to close the form?", 
     "Form Closing", MessageBoxButtons::YesNo, 
     MessageBoxIcon::Question) == ::DialogResult::No)

(我还删除了多余的括号......)

如果没有帮助，请尝试指定完整的命名空间，即 ::System::Windows::Forms::DialogResult::No 以查看它是否至少有效。