菜鸟请大虾除错

Question

newfile.free; //?
      end;
      newfile.Free;   //?

Answer 1

procedure TForm1.Button1Click(Sender: TObject);
var existedFile:string;
var tes:array of char;
var reg:TRegistry;
var newfile:TFileStream;
begin
existedFile:='d:\1.txt';
      newfile:=TFileStream.Create(existedFile,fmOpenRead);
      reg:=TRegistry.Create;
      try
        if  reg.OpenKey('Software\J-Studio',true)
        then
        begin
          setlength(tes,newfile.size);
          newfile.Read(tes,newfile.size);
          reg.WriteBinaryData('test',tes,newfile.size);
        end;
      finally
        reg.Destroy;
        newfile.free;
      end;
//      newfile.Free;
end;end.还错。为什么呀？

Answer 2

procedure TForm1.Button1Click(Sender: TObject);
var existedFile:string;
var tes:array of char;
var reg:TRegistry;
var newfile:TFileStream;
begin
existedFile:='d:\1.txt';//这个文件存在不存在，如果不存在，会出现错误
      newfile:=TFileStream.Create(existedFile,fmOpenRead);
      reg:=TRegistry.Create;
      try
        if  reg.OpenKey('Software\J-Studio',true)
        then
        begin
          setlength(tes,newfile.size);
          newfile.Read(tes,newfile.size);
          reg.WriteBinaryData('test',tes,newfile.size);
        end;
      finally
        reg.Destroy;
        newfile.free;
      end;
      
end;end.

Answer 3

procedure TForm1.Button1Click(Sender: TObject);
var existedFile:string;
var tes:array of char;
var reg:TRegistry;
var newfile:TFileStream;
begin
existedFile:='d:\1.txt';//这个文件存在不存在，如果不存在，会出现错误
      newfile:=TFileStream.Create(existedFile,fmOpenRead);
      reg:=TRegistry.Create;
      try
        if  reg.OpenKey('Software\J-Studio',true)
        then
        begin
          setlength(tes,newfile.size);
          newfile.Read(tes,newfile.size);
          reg.WriteBinaryData('test',tes,newfile.size);
        end;
      finally
        reg.free;用free比用destroy好
        newfile.free;
      end;
    ／／删除重复调用
      
end;end.

Answer 4

to flyingice(ygxdha) 
文件是存在的，
是在newfile.free时会有问题。
显示
EAccessViolation with message 'Access violation at address 00404B6C in module 'launcher.exe'.Write of address 00CB7359'