//ShowMessage:begin  ShowMessage('提示内容');      {标题默认工程名, 如: Proect1}  Application.Title := '警告';  {如果修改工程标题...}  ShowMessage('提示内容');      {标题是'警告'}  ShowMessage('第一行' + #13#10 + '第二行');  {提示信息换行}  ShowMessage('第一行'#13'第二行');     {也可以}end;         //InputBox:var  s: string;begin  s := InputBox('标题','提示信息','默认输入');  ShowMessage(s);  //显示输入的内容end;         //InputQuery:var  s: string;begin  InputQuery('标题','提示信息',s);  //为字符串变量 S 输入值, 返回布尔型  ShowMessage(s);  //显示输入的内容end;         //MessageBox:var  i: Integer;begin  i := MessageBox(0,'提示内容','标题',mrOk);  //第一个参数一般用 Self.Handle, 0代表桌面  //可选参数     //mrNone  //mrOk  //mrCancel  //mrAbort  //mrRetry  //mrIgnore  //mrYes  //mrNo  //mrAll  //mrNoToAll  //mrYesToAll  ShowMessage(IntToStr(i));  //还可以组合第四个参数以调用不同的图标:  MessageBox(0,'提示内容','标题',mrOk + MB_ICONHAND);  //MB_ICONHAND  //MB_ICONQUESTION  //MB_ICONEXCLAMATION  //MB_ICONASTERISK  //MB_USERICON  //MB_ICONWARNING  //MB_ICONERROR  //MB_ICONINFORMATION  //MB_ICONSTOPend;//后来补充, 还是应该使用 API 的原有参数更好些:{可选参数或它们的组合}MB_OK                        = $00000000;MB_OKCANCEL                  = $00000001;MB_ABORTRETRYIGNORE          = $00000002;MB_YESNOCANCEL               = $00000003;MB_YESNO                     = $00000004;MB_RETRYCANCEL               = $00000005;MB_ICONHAND                  = $00000010;MB_ICONQUESTION              = $00000020;MB_ICONEXCLAMATION           = $00000030;MB_ICONASTERISK              = $00000040;MB_USERICON                  = $00000080;MB_ICONWARNING               = MB_ICONEXCLAMATION;MB_ICONERROR                 = MB_ICONHAND;MB_ICONINFORMATION           = MB_ICONASTERISK;MB_ICONSTOP                  = MB_ICONHAND;MB_DEFBUTTON1                = $00000000;MB_DEFBUTTON2                = $00000100;MB_DEFBUTTON3                = $00000200;MB_DEFBUTTON4                = $00000300;MB_APPLMODAL                 = $00000000;MB_SYSTEMMODAL               = $00001000;MB_TASKMODAL                 = $00002000;MB_HELP                      = $00004000;MB_NOFOCUS                   = $00008000;MB_SETFOREGROUND             = $00010000;MB_DEFAULT_DESKTOP_ONLY      = $00020000;MB_TOPMOST                   = $00040000;MB_RIGHT                     = $00080000;MB_RTLREADING                = $00100000;MB_SERVICE_NOTIFICATION      = $00200000;MB_SERVICE_NOTIFICATION_NT3X = $00040000;MB_TYPEMASK                  = $0000000F;MB_ICONMASK                  = $000000F0;MB_DEFMASK                   = $00000F00;MB_MODEMASK                  = $00003000;MB_MISCMASK                  = $0000C000;{可能的返回值}IDOK       = 1;   ID_OK = IDOK;IDCANCEL   = 2;   ID_CANCEL = IDCANCEL;IDABORT    = 3;   ID_ABORT = IDABORT;IDRETRY    = 4;   ID_RETRY = IDRETRY;IDIGNORE   = 5;   ID_IGNORE = IDIGNORE;IDYES      = 6;   ID_YES = IDYES;IDNO       = 7;   ID_NO = IDNO;IDCLOSE    = 8;   ID_CLOSE = IDCLOSE;IDHELP     = 9;   ID_HELP = IDHELP;IDTRYAGAIN = 10;IDCONTINUE = 11;         //MessageDlg:var  i: Integer;begin  MessageDlg('提示信息',mtWarning,mbYesNo,0);  //第二个参数调用不同的图标:  //mtWarning  //mtError  //mtInformation  //mtConfirmation  //mtCustom  //第三个参数调用不同的按钮:  //mbYesNo = [mbYes, mbNo];  //mbYesNoCancel = [mbYes, mbNo, mbCancel];  //mbYesAllNoAllCancel = [mbYes, mbYesToAll, mbNo, mbNoToAll, mbCancel];  //mbOKCancel = [mbOK, mbCancel];  //mbAbortRetryIgnore = [mbAbort, mbRetry, mbIgnore];  //mbAbortIgnore = [mbAbort, mbIgnore];  //可以直接输入集合元素,譬如: MessageDlg('aaa',mtWarning,[mbYes],1);  //第四个参数帮助ID, 没有添0  //还有重载的第5个参数是设定默认按钮  //如果要本地话显示需要修改源文件, 一般可以用 MessageBox 代替end;         //MessageDlgPos:begin  MessageDlgPos('提示信息',mtCustom,mbYesNoCancel,0,400,100);  //比 MessageDlg 多出两个参数来控制显示位置end;