如何判断olevar变量值是否为空？？(100分)

H

hu_jun

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GUEST, unregistred user!

• 2002-10-21

• #1

下列代码
AnsiString type = xmlnode->ChildNodes->Nodes->Attributes[WideString("Value")]
提示“Could not convert variant of type (Null) into type (String)“
原因是因为xmlnode->ChildNodes->Nodes->Attributes[WideString("Value")]返回的
值是空，如何写强制转换的函数？

 

D

dz2050

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• 2002-10-21

• #2

olevar is null

 

H

hu_jun

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• 2002-10-21

• #3

xmlnode->ChildNodes->Nodes->Attributes[WideString("Value")]
返回的值放在olevariant中，如何判断是否为空？

thanks for dz2050. is null 用于SQL

 

P

Pearl.

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• 2002-10-21

• #4

(olevariant=nil) or (olevariant=null)

 

H

hu_jun

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• 2002-10-21

• #5

在BCB中
if ( xmlnode->ChildNodes->Nodes->Attributes[WideString("Value")] != NULL )
好像不起作用，判断不了是否为空。why?

 

Q

Qiuliang

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• 2002-10-21

• #6

function VarIsNull;

 

C

chuguozhen

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• 2002-10-22

• #7

Try this
if ( xmlnode->ChildNodes->Nodes->Attributes[WideString("Value")] != UnAssigned )