CODEWITHSUNDEEP
c++-cli
Part Time User
Part Time User

Reputation: 333

C++/CLI - Convert System::Object to ContextMenuStrip

I'm working on a piece of legacy code & I'm trying to update some of the interface. I'm not proficient in C++/CLI and the documentation for C++/CLI is sparse at best. I do my best to convert C# documentation to C++/CLI but it doesn't always work.

I want to convert a System::Object to a ContextMenuStrip.

A sample code is:

System::Void Form1::unzoomToolStripMenuItem_Click(System::Object^ sender, System::EventArgs^ e)
{

    System::Windows::Forms::ContextMenuStrip ^menu = sender;
    //a value of type "System::Object ^" cannot be used to initialize and entity of type "System::Windows::Forms::ContextMenuStrip ^"

    //Other code here
}

How is this done in C++/CLI?

Upvotes: 0

Views: 278

Answers (1)

Tim Styles
Tim Styles

Reputation: 154

From the link posted by Hans Passant:

A downcast is a cast from a base class to a class that's derived from the base class. A downcast is safe only if the object that's addressed at runtime is actually addressing a derived class object. Unlike static_cast, safe_cast performs a dynamic check and throws InvalidCastException if the conversion fails.

So you should use:

Windows::Forms::ContextMenuStrip ^menu = safe_cast<Windows::Forms::ContextMenuStrip^>(sender);

Upvotes: 2

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