【搞定】关于类型转换的问题[请求]**

ccyy0112

date:TDate;
  month :TDatetime;
begin
    date:=business.Data.SysSrv.SysService.Time;
    month:=Business.System.DateUtils.MonthOf(date);  3
    s4 := sysutils.DateToStr(month);   1900-1-2
我的代码 month 的值取出了当前月
给S4赋值的时候 数值就变成 1900-1-2了 为什么啊

jiahaiminghr

DateUtils.MonthOf返回的应该是整数吧！

ccyy0112

是整数 我要在程序里组合字符串 所以要将 month的类型转换为STRING
procedure TGZB4.Button4Click(Sender: TObject);
var
   s,s3,s4:string;
   s1,s2ouble;
  date:TDate;
  month :TDatetime;
begin
    date:=business.Data.SysSrv.SysService.Time;
    month:=Business.System.DateUtils.MonthOf(date);
    s4 :=  sysutils.DateToStr(month);
    datasetbroker1.DataSet.Open;
    datasetbroker1.DataSet.First;
    memo1.Text := '';
    while not datasetbroker1.DataSet.Eof do
    begin
      if(datasetbroker1.DataSet.FieldByName('yxzh').AsString <> '')       then
       begin
       s := datasetbroker1.DataSet.FieldByName('YXZH').AsString;
       s1 :=datasetbroker1.DataSet.FieldByName('SL').AsFloat;
       s3 := sysutils.FloatToStr(s1);
       memo1.Lines.Add(s+' 00'+s3+'00');
       end;
    datasetbroker1.DataSet.Next;

    end;
    memo1.Lines.SaveToFile('C:\'''+s4+'''月份员工银行帐号及工资.txt');
end;

alang

s4 :=  sysutils.IntToStr(month);
这里month应该是整数了，不是日期时间
2007年3月29日 是一个日期
但是 3 是一个整数
所以这里应该定义一个整数类型，用IntToStr

alang

日期类型实际上就是一个浮点数
TDateTime is a used by the date and time routines to hold date and time values.

Unit

System

type TDateTime = type Double;

Description

Most VCL objects represent date and time values using the TDateTime type. The integral part of a TDateTime value is the number of days that have passed since 12/30/1899. The fractional part of a TDateTime value is fraction of a 24 hour day that has elapsed.

Following are some examples of TDateTime values and their corresponding dates and times:

0        12/30/1899 12:00 am
2.75        1/1/1900 6:00 pm
-1.25        12/29/1899 6:00 am
35065        1/1/1996 12:00 am
To find the fractional number of days between two dates, simply subtract the two values, unless one of the TDateTime values is negative. Similarly, to increment a date and time value by a certain fractional number of days, add the fractional number to the date and time value if the TDateTime value is positive.
When working with negative TDateTime values, computations must handle time portion separately. The fractional part reflects the fraction of a 24-hour day without regard to the sign of the TDateTime value. For example, 6:00 am on 12/29/1899 is ?.25, not ? + 0.25, which would be ?.75. There are no TDateTime values between ? and 0.

Note:        Delphi 1.0 calculated the date from year 1 instead of from 1899. To convert a Delphi 1.0 date to a TDateTime value in later versions of Delphi or in Kylix, subtract 693594.0 from the Delphi 1.0 date. The date format changed to be more compatible with OLE 2.0 Automation.

alang

所以
0   12/30/1899 12:00 am
3   1900-1-2

ccyy0112

搞定  谢谢