怎样判断一个过程变量是否为Nil(50分)

X

xself

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• 2003-12-22

• #1

怎样判断一个过程变量是否为Nil?

 

W

wlmmlw

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• 2003-12-22

• #2

if (myEvent = nil) then

 

C

coldwind8112

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• 2003-12-22

• #3

if ???=NIL 啊

 

H

hongxing_dl

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• 2003-12-22

• #4

type
tproc=procedure (a,b:string);
//
var
proc1:tproc;
////
IF ASSIGNED(proc1) then

or

if proc1=nil then

 

A

andy263

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• 2003-12-22

• #5

IF XXX=NIL

 

C

coldwind8112

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• 2003-12-22

• #6

对ASSIGN也行

 

X

xself

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• 2003-12-22

• #7

对于XXX=Nil好象不行的,它变成了计算XXX的反回值是不是为Nil了

 

H

hongxing_dl

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• 2003-12-22

• #8

对于XXX=Nil好象不行的,它变成了计算XXX的反回值是不是为Nil了
？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？
type
tproc=procedure (a,b:string);///////这个是必须定义的
//
var
proc1:tproc;
////
proc1:=yourproc;
IF ASSIGNED(proc1) then

or

if proc1=nil then

 

L

lichengbin

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• 2003-12-22

• #9

if Assigned(Proc) then
or
if @Proc = nil then

 

飞

飞扬的花瓣

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• 2003-12-22

• #10

is NULL

 

S

squall

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• 2003-12-26

• #11

Assigned(Proc)

 

X

xuxiaohan

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• 2003-12-26

• #12

还有这么多人回答
Delphi推荐的方法是 if assigned(onClick) then .....

 

X

xself

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• 2004-01-14

• #13

接受答案了.