错误 C3861 图形 CopyFromScreen：找不到标识符

Question

我正在使用 Visual Studio 2010，我正在编写代码以在单击按钮时捕获屏幕。我把代码写成

 private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {
         try
         {
             SaveFileDialog^ save = gcnew SaveFileDialog();
             save->Title = "Save Screenshot";
             save->Filter = "JPEG | *.jpg | Bitmap | *.bmp | Portable Network Graphics|*.png|Graphical Interchange File Format|*.gif";
             save->ShowDialog();
             pictureBox1->Image->Save(save->FileName);
         }
         catch(Exception^ ex)
         {
         MessageBox::Show(ex->Message);

         }


     }
private: System::Void Form1_KeyDown(System::Object^  sender, System::Windows::Forms::KeyEventArgs^  e) {
         if(e->KeyCode == System::Windows::Forms::Keys::Enter)
         {
             Rectangle^ bounds;
             System::Drawing::Bitmap^ screenshot;
             Graphics^ graph;
             bounds = Screen::PrimaryScreen->Bounds;
             screenshot = gcnew System::Drawing::Bitmap(bounds->Width,bounds->Height, System::Drawing::Imaging::PixelFormat::Format32bppArgb);
             graph = Graphics::FromImage(screenshot);
             graph = CopyFromScreen (bounds->X, bounds->Y, 0, 0, bounds-> Size, CopyPixelOperation::SourceCopy);
             pictureBox1->Image = screenshot;

     }
     }

但是我收到了一个错误，因为 CopyFromScreen:Identifier not found。我试图搜索 abt 这个和它显示语法正确的所有地方。

Answer 1

假设CopyFromScreen 不是您的示例中未包含的自定义free function，它是member of the Graphics class。

你应该这样调用它（就像你在上面的行中使用 Graphics::FromImage() 一样：

graph = Graphics::CopyFromScreen(bounds->X, bounds->Y, 0, 0, bounds-> Size, CopyPixelOperation::SourceCopy);

编辑

为了解决您的评论和我的疏忽： CopyFromScreen 不是静态的，因此必须在您需要首先创建的特定对象上调用它：

graph.CopyFromScreen(bounds->X, bounds->Y, 0, 0, bounds-> Size, CopyPixelOperation::SourceCopy);