Как присвоить все значения полей одного класса, другому такому же классу
Автор: Serge Gubenko
How can I assign all property values (or if it's not possible only published property values, or some of them) of one class (TComponent) to another instance of the same class? What I want to do is:
MyComponent1. {property1} := MyComponent2. {property1};
{...}
MyComponent2. {propertyN} := MyComponent2. {propertyN};
Is there a better and shorter way to do this? I tried this: MyComponent1 := MyComponent2; But it doesn't work. Why not? Can I point to the second component ?
MyComponent2 and MyComponent1 are pointers to your components, and this kind of assigment leads to MyComponent1 pointing to MyComponent2. But it will not copy its property values.
A better way is to override the assign method of your control, do all property assignment there and call it when you need to copy component attributes. Here's example:
procedure TMyComponent.Assign(Source: TPersistent);
begin
if Source is TMyComponent then
begin
property1 := TMyComponent(Source).property1;
{ ... }
end
else
inherited Assign(Source);
end;
To assign properties you'll need to set this line in the code:
MyComponent1.Assign(MyComponent2);
|