Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
1.5k views
in Technique[技术] by (71.8m points)

delphi - Best way to sort an array

Say I have an array of records which I want to sort based on one of the fields in the record. What's the best way to achieve this?

TExample = record
  SortOrder : integer;
  SomethingElse : string;
end;

var SomeVar : array of TExample;
See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You can add pointers to the elements of the array to a TList, then call TList.Sort with a comparison function, and finally create a new array and copy the values out of the TList in the desired order.

However, if you're using the next version, D2009, there is a new collections library which can sort arrays. It takes an optional IComparer<TExample> implementation for custom sorting orders. Here it is in action for your specific case:

TArray.Sort<TExample>(SomeVar , TDelegatedComparer<TExample>.Construct(
  function(const Left, Right: TExample): Integer
  begin
    Result := TComparer<Integer>.Default.Compare(Left.SortOrder, Right.SortOrder);
  end));

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...