creating a firemonkey component

问题:

I'm working with Firemonkey in Delphi XE4 and I'm unable to create a new component using the menu item Component -> New Component. Whether the component is a VCL or Firemonkey component or whether I create a package first the result is the same. The Tool Palette in Delphi appears to be searched and gradually it closes leaving it empty of components and a component dialog box that says "No Items available" when it comes to selecting an ancestor component.

I have two separate installations of Delphi XE4 and the same symptoms appear on both. It appears that Delphi believes that there are no suitable base components on which to build a new component.

回答1:

Creating components is fairly straightforward in code.

• Create a unit.
• Add code for your component.

• Add a Register procedure.

  procedure Register;
  begin
    RegisterComponents('NewPage', [TMyComponent]);
  end;
  

• Add a declaration for Register in the implements section.

• Add a call to RegisterFMXClasses in your initialization section.

  implementation
  uses FMX.Types;
  ...
  initialization
    RegisterFMXClasses([TMyComponent]);
  end.
  

• Create a package.

• Add the unit to the package.
• Right-click the package (in the top-right panel) and select Install.

(Note: It's usually best to create your component at run time whilst testing. You only need to do the package stuff once it's fairly stable).