date类型的转换(50分)

C

chenghus

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GUEST, unregistred user!

• 2000-04-10

• #1

var
date1: string;
date2: tdate;
begin
date1='sdfdsfd';
date2=strtodate(date1);
end;
如何判断date1是有效的日期格式。以让第二句不出错。

 

沈

沈前卫

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• 2000-04-10

• #2

var
IsDateTime:boolean;
date1: string;
date2: tdate;
begin
IsDateTime:=True;
date1='sdfdsfd';
try
date2=strtodate(date1);
except
IsDateTime:=False;
end;
if IsDateTime then ShowMessage(date1+' is valid datetime');
end;

 

C

chenghus

Unregistered / Unconfirmed

GUEST, unregistred user!

• 2000-04-10

• #3

有没有直接判断的函数，而不用错误拦截。

 

F

Fudei

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GUEST, unregistred user!

• 2000-04-10

• #4

同意前卫兄的回答.

 

F

Fudei

Unregistered / Unconfirmed

GUEST, unregistred user!

• 2000-04-10

• #5

不要给我分.

function isDate(val: string): Boolean;
begin
Result:=True;
try
strtoData(val);
except
result:=False;
end;
end;

 

L

liuchuanbo

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GUEST, unregistred user!

• 2000-04-10

• #6

function isDate(val: string): Boolean;
begin
Result:=True;
try
strtoData(val);
except
on econverterror do
begin
showmessage('it is not a datetype data');
result:=False;
end;
end;
end;

 

K

Kang

Unregistered / Unconfirmed

GUEST, unregistred user!

• 2000-04-10

• #7

》liuchuanbo
哈哈，showmessage放早了

应该这样吧：
if isDate then ....
else showmessage('it is not a datetype data');

 

L

liuchuanbo

Unregistered / Unconfirmed

GUEST, unregistred user!

• 2000-04-11

• #8

>> Kang
You are wrong

 

K

Kang

Unregistered / Unconfirmed

GUEST, unregistred user!

• 2000-04-11

• #9

isDate(string1) then ...
else Showmessage(string1+'is not a valid date.Abort!');
isDate(string2) then ...
else Showmessage(string2+'is not a valid date.');

如果函数里有Showmessage，那么我就只能显示固定格式的信息了

 

L

liuchuanbo

Unregistered / Unconfirmed

GUEST, unregistred user!

• 2000-04-11

• #10

现在研究方法
也是本问题的主题
况且except在此相当于else的效果

 

千

千中元

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GUEST, unregistred user!

• 2000-04-11

• #11

直接控制输入的格式不好么？
太多的except 不好吧

 

C

chenghus

Unregistered / Unconfirmed

GUEST, unregistred user!

• 2000-04-14

• #12

多人接受答案了。