书本实例3 单选按钮和复选按钮

《Delphi 7编程技巧与实例精解》实例3

看了题目以后我先按本身的思路实现了，我是在点击“显示”按键的时候再一次性检查控件的属性，来肯定ShowMessage的内容。
书本给出的程序样例是在每次用户点击控件的时候就更新一次存有message内容的变量，我想这样应该比较浪费资源吧，不过程序很小，估计没影响。

姓名、性别、学习成绩这些都相对简单。兴趣爱好那里，创建一个flag变量来肯定是否有选择。感受写了好多行把flag设置为True的代码，不知道VCL自己有没有更简单的函数来提供这个检验。

 

unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.ExtCtrls;

type
  TForm1 = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Button1: TButton;
    Edit1: TEdit;
    RadioButton1: TRadioButton;
    RadioButton2: TRadioButton;
    RadioGroup1: TRadioGroup;
    GroupBox1: TGroupBox;
    CheckBox1: TCheckBox;
    CheckBox2: TCheckBox;
    CheckBox3: TCheckBox;
    CheckBox4: TCheckBox;
    CheckBox5: TCheckBox;
    CheckBox6: TCheckBox;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

var
  name,gender,grade,hobbies: String;
  hobbyList: Array of String;


procedure TForm1.Button1Click(Sender: TObject);
var
  msg,hobby: String;
  hobbiesFlag: Boolean;

begin
  //clear
  name := '';
  gender := '';
  grade := '';
  hobbies := '';
  hobbiesFlag := False;

  setLength(hobbyList,6);
  hobbyList[0] :='文学';
  hobbyList[1] :='音乐';
  hobbyList[2] :='棋牌';
  hobbyList[3] :='绘画';
  hobbyList[4] :='体育';
  hobbyList[5] :='数学';

  //set name
  name := Edit1.Text;

  //set gender
  if RadioButton1 .Checked then
    gender := '男';
  if RadioButton2.Checked then
    gender := '女';

  //set grade
  if RadioGroup1.ItemIndex > -1 then
    case RadioGroup1.ItemIndex of
      0: grade := '优';
      1: grade := '良';
      2: grade := '中';
      3: grade := '差';
    end;

  //set hobbies
  if CheckBox1.Checked then
  begin
    hobbiesFlag := True;
    hobby := hobby + hobbyList[0] + '、';
  end;
  if CheckBox2.Checked then
  begin
    hobbiesFlag := True;
    hobby := hobby + hobbyList[1] + '、';
  end;
  if CheckBox3.Checked then
  begin
    hobbiesFlag := True;
    hobby := hobby + hobbyList[2] + '、';
  end;
  if CheckBox4.Checked then
  begin
    hobbiesFlag := True;
    hobby := hobby + hobbyList[3] + '、';
  end;
  if CheckBox5.Checked then
  begin
    hobbiesFlag := True;
    hobby := hobby + hobbyList[4] + '、';
  end;
  if CheckBox6.Checked then
  begin
    hobbiesFlag := True;
    hobby := hobby + hobbyList[5] + '、';
  end;

  //show message
  if name = '' then
    showMessage('请输入名字')
  else if gender = '' then
    showMessage('请输入性别')
  else if grade = '' then
    showMessage('请输入成绩')
  else if hobbiesFlag = False then
    showMessage('请选择爱好')
  else
  begin
    msg := '您的姓名是：'+name+ #13#10 +
           '您的性别是：'+gender+ #13#10 +
           '您的学习成绩是：'+grade+ #13#10 +
           '您的爱好是：' + hobby;
    msg[msg.Length] := #13;
    msg := msg + #10;
    ShowMessage(msg);

end;
end;
end.

运行结果：