如何判断 TComboBox.Items.Objects[i] 释放释放 Assigned不行

Question

if Assigned(TComboBox.Items.Objects[i]) then 
   TComboBox.Items.Objects[i].free; 释放过了 还是返回true

Answer 1

if   Assigned(TComboBox.Items.Objects[i])   then  
begin
      TComboBox.Items.Objects[i].Free;  
      TComboBox.Items.Objects[i] := nil; 
end;

Answer 2

budded 
All By Myself 
等 级：
 发表于：2008-01-24 16:25:031楼 得分:0 
if       Assigned(TComboBox.Items.Objects[i])       then     
begin 
            TComboBox.Items.Objects[i].Free;     
            TComboBox.Items.Objects[i]   :=   nil;   
end; 
 
===================================================
我用freeandnil（TComboBox.Items.Objects[i]） 就不行 2者有什么区别 呢 

Answer 3

procedure FreeAndNil(var Obj);
var
  Temp: TObject;
begin
  Temp := TObject(Obj);
  Pointer(Obj) := nil;
  Temp.Free;
end;

Answer 4

var
  nObject: TObject;
begin
...
  nObject := TComboBox.Items.Objects[i];
  if Assigned(nObject) then 
    FreeAndNil(nObject);
...