遇到问题了。

。Yh

   学DELPHI到第四课，可爱的鱼老师要叫做个计算器，我把界面都做好了，结果发现进行不下去了！！

                               
登录/注册后可看大图

目前问题如下：
  1、不知道怎么进行运算操作，只有一个EDIT，就搞不明白怎么算了，网上查，完全看不懂。
  2、鱼老师说从后面输入，不知道怎么调，网上查完全看不懂。

代码在下面：
unit jishuanqi;
interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls, Buttons, jpeg;
type
  TForm1 = class(TForm)
    Image1: TImage;
    Edit1: TEdit;
    SpeedButton1: TSpeedButton;
    SpeedButton2: TSpeedButton;
    SpeedButton3: TSpeedButton;
    SpeedButton4: TSpeedButton;
    SpeedButton5: TSpeedButton;
    SpeedButton6: TSpeedButton;
    SpeedButton7: TSpeedButton;
    SpeedButton8: TSpeedButton;
    SpeedButton9: TSpeedButton;
    SpeedButton10: TSpeedButton;
    SpeedButton11: TSpeedButton;
    SpeedButton12: TSpeedButton;
    SpeedButton13: TSpeedButton;
    SpeedButton14: TSpeedButton;
    SpeedButton15: TSpeedButton;
    SpeedButton16: TSpeedButton;
    SpeedButton17: TSpeedButton;
    SpeedButton18: TSpeedButton;
    SpeedButton19: TSpeedButton;
    procedure SpeedButton1Click(Sender: TObject);
    procedure SpeedButton2Click(Sender: TObject);
    procedure SpeedButton3Click(Sender: TObject);
    procedure SpeedButton4Click(Sender: TObject);
    procedure SpeedButton5Click(Sender: TObject);
    procedure SpeedButton6Click(Sender: TObject);
    procedure SpeedButton7Click(Sender: TObject);
    procedure SpeedButton8Click(Sender: TObject);
    procedure SpeedButton9Click(Sender: TObject);
    procedure SpeedButton10Click(Sender: TObject);
    procedure SpeedButton12Click(Sender: TObject);
    procedure SpeedButton11Click(Sender: TObject);
    procedure SpeedButton13Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
var
  Form1: TForm1;
  a:string;
implementation
{$R *.dfm}
procedure TForm1.SpeedButton1Click(Sender: TObject);
begin
  Edit1.Text:=Edit1.text+'1';
end;
procedure TForm1.SpeedButton2Click(Sender: TObject);
begin
  Edit1.Text:=Edit1.text+'2';
end;
procedure TForm1.SpeedButton3Click(Sender: TObject);
begin
  Edit1.Text:=Edit1.Text+'3';
end;
procedure TForm1.SpeedButton4Click(Sender: TObject);
begin
  Edit1.Text:=Edit1.Text+'4';
end;
procedure TForm1.SpeedButton5Click(Sender: TObject);
begin
  Edit1.Text:=Edit1.Text+'5';
end;
procedure TForm1.SpeedButton6Click(Sender: TObject);
begin
  Edit1.Text:=Edit1.Text+'6';
end;
procedure TForm1.SpeedButton7Click(Sender: TObject);
begin
  Edit1.Text:=Edit1.Text+'7';
end;
procedure TForm1.SpeedButton8Click(Sender: TObject);
begin
  Edit1.Text:=Edit1.Text+'8';
end;
procedure TForm1.SpeedButton9Click(Sender: TObject);
begin
  Edit1.Text:=Edit1.Text+'9';
end;
procedure TForm1.SpeedButton10Click(Sender: TObject);
begin
  Edit1.Text:=Edit1.Text+'0';
end;
procedure TForm1.SpeedButton12Click(Sender: TObject);
begin
  Edit1.Text:=Edit1.Text+'.';
end;
procedure TForm1.SpeedButton11Click(Sender: TObject);
begin
  Edit1.Text:=Edit1.Text+'00';
end;
procedure TForm1.SpeedButton13Click(Sender: TObject);
begin
    a:=Edit1.Text;
    Edit1.Text:=FloatToStr(StrToFloat(a)+StrToFloat(Edit1.Text));
end;
end.

天空是黑的

图片挂了。把源码发上来。

woawn

老兄我上面的没看就看最后一句Edit1.Text:=FloatToStr(StrToFloat(a)+StrToFloat(Edit1.Text));，这个也太矛盾了吧，第一个先把浮点型转化为字符型，第二句却把字符型转化为浮点型

。Yh

我怎么还是新鱼友呢？:cry

哥哥123

我来看看