在VB.NET中处理构造
函数时，有两个陈述值得注意：
(1)如果类型不包含任何实例构造
函数声明，则VB.NET提供
默认的构造
函数；
默认参数
调用直接基类的无参数构造
函数。如果基类没有可访问的无参数构造
函数，则发生编译期
错误。
(2)构造
函数不能继承；
陈述（1）包含两个方面的信息：①是如果类型不包含任何实例构造
函数声明，则VB.NET提供
默认的构造
函数，即下面的声明是允许的，在类Shape中我们没有显式声明任何构造
函数，但是我们仍然可以通过VB.NET
自动提供的无参数构造
函数New()来实例化类；
![]()
display='none'; CodeHighlighter1_0_83_Open_Text.style.display='none'; CodeHighlighter1_0_83_Closed_Image.style.display='inline'; CodeHighlighter1_0_83_Closed_Text.style.display='inline';" id="CodeHighlighter1_0_83_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif">
![]()
display='none'; CodeHighlighter1_0_83_Closed_Text.style.display='none'; CodeHighlighter1_0_83_Open_Image.style.display='inline'; CodeHighlighter1_0_83_Open_Text.style.display='inline';" id="CodeHighlighter1_0_83_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif">
ModuleTest
ModuleTest
![]()
display='none'; CodeHighlighter1_20_72_Open_Text.style.display='none'; CodeHighlighter1_20_72_Closed_Image.style.display='inline'; CodeHighlighter1_20_72_Closed_Text.style.display='inline';" id="CodeHighlighter1_20_72_Open_Image" style="display: inline" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif">
![]()
display='none'; CodeHighlighter1_20_72_Closed_Text.style.display='none'; CodeHighlighter1_20_72_Open_Image.style.display='inline'; CodeHighlighter1_20_72_Open_Text.style.display='inline';" id="CodeHighlighter1_20_72_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif">
PublicSubMain()SubMain()
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
Dimshape1AsShape=NewShape
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif">
EndSub
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif">
EndModule
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/None.gif">
![]()
display='none'; CodeHighlighter1_93_161_Open_Text.style.display='none'; CodeHighlighter1_93_161_Closed_Image.style.display='inline'; CodeHighlighter1_93_161_Closed_Text.style.display='inline';" id="CodeHighlighter1_93_161_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif">
![]()
display='none'; CodeHighlighter1_93_161_Closed_Text.style.display='none'; CodeHighlighter1_93_161_Open_Image.style.display='inline'; CodeHighlighter1_93_161_Open_Text.style.display='inline';" id="CodeHighlighter1_93_161_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif">
Public
ClassShape
ClassShape
![]()
display='none'; CodeHighlighter1_113_151_Open_Text.style.display='none'; CodeHighlighter1_113_151_Closed_Image.style.display='inline'; CodeHighlighter1_113_151_Closed_Text.style.display='inline';" id="CodeHighlighter1_113_151_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif">
![]()
display='none'; CodeHighlighter1_113_151_Closed_Text.style.display='none'; CodeHighlighter1_113_151_Open_Image.style.display='inline'; CodeHighlighter1_113_151_Open_Text.style.display='inline';" id="CodeHighlighter1_113_151_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif">
PublicSubDraw()SubDraw()
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
'somecodeshere.
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif">
EndSub
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif">
EndClass
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/None.gif">
②是如果类型中包含有实例构造
函数的声明，那么VB.NET不再提供
默认的构造
函数，例如，我们在类Shape中
添加了
一个带参数的构造
函数，
![]()
display='none'; CodeHighlighter1_7_144_Open_Text.style.display='none'; CodeHighlighter1_7_144_Closed_Image.style.display='inline'; CodeHighlighter1_7_144_Closed_Text.style.display='inline';" id="CodeHighlighter1_7_144_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif">
![]()
display='none'; CodeHighlighter1_7_144_Closed_Text.style.display='none'; CodeHighlighter1_7_144_Open_Image.style.display='inline'; CodeHighlighter1_7_144_Open_Text.style.display='inline';" id="CodeHighlighter1_7_144_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif">
Public
ClassShape
ClassShape
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
Private_ptAsPoint
![]()
display='none'; CodeHighlighter1_49_86_Open_Text.style.display='none'; CodeHighlighter1_49_86_Closed_Image.style.display='inline'; CodeHighlighter1_49_86_Closed_Text.style.display='inline';" id="CodeHighlighter1_49_86_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif">
![]()
display='none'; CodeHighlighter1_49_86_Closed_Text.style.display='none'; CodeHighlighter1_49_86_Open_Image.style.display='inline'; CodeHighlighter1_49_86_Open_Text.style.display='inline';" id="CodeHighlighter1_49_86_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif">
PublicSubNew()SubNew(pAsPoint)
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
_pt=p
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif">
EndSub
![]()
display='none'; CodeHighlighter1_96_134_Open_Text.style.display='none'; CodeHighlighter1_96_134_Closed_Image.style.display='inline'; CodeHighlighter1_96_134_Closed_Text.style.display='inline';" id="CodeHighlighter1_96_134_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif">
![]()
display='none'; CodeHighlighter1_96_134_Closed_Text.style.display='none'; CodeHighlighter1_96_134_Open_Image.style.display='inline'; CodeHighlighter1_96_134_Open_Text.style.display='inline';" id="CodeHighlighter1_96_134_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif">
PublicSubDraw()SubDraw()
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
'somecodeshere.
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif">
EndSub
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif">
EndClass
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/None.gif">
那么，如果直接实例化类时，则会产生
错误；
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/None.gif">
Dim
shape1
As
Shape
=
New
Shape
只能通过
调用Shape类中显式声明的带参数的构造
函数来实例化类，如下，
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/None.gif">
Dim
shape1
As
Shape
=
New
Shape(
New
Point(
0
,
0
))
因此，如果要在类中同时使用无参数和带参数的构造
函数，必须同时显式地声明两种构造
函数。
![]()
display='none'; CodeHighlighter1_7_191_Open_Text.style.display='none'; CodeHighlighter1_7_191_Closed_Image.style.display='inline'; CodeHighlighter1_7_191_Closed_Text.style.display='inline';" id="CodeHighlighter1_7_191_Open_Image" style="display: inline" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif">
![]()
display='none'; CodeHighlighter1_7_191_Closed_Text.style.display='none'; CodeHighlighter1_7_191_Open_Image.style.display='inline'; CodeHighlighter1_7_191_Open_Text.style.display='inline';" id="CodeHighlighter1_7_191_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif">
Public
ClassShape
ClassShape
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
Private_ptAsPoint
![]()
display='none'; CodeHighlighter1_49_86_Open_Text.style.display='none'; CodeHighlighter1_49_86_Closed_Image.style.display='inline'; CodeHighlighter1_49_86_Closed_Text.style.display='inline';" id="CodeHighlighter1_49_86_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif">
![]()
display='none'; CodeHighlighter1_49_86_Closed_Text.style.display='none'; CodeHighlighter1_49_86_Open_Image.style.display='inline'; CodeHighlighter1_49_86_Open_Text.style.display='inline';" id="CodeHighlighter1_49_86_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif">
PublicSubNew()SubNew()
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
'somecodeshere.
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif">
EndSub
![]()
display='none'; CodeHighlighter1_96_133_Open_Text.style.display='none'; CodeHighlighter1_96_133_Closed_Image.style.display='inline'; CodeHighlighter1_96_133_Closed_Text.style.display='inline';" id="CodeHighlighter1_96_133_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif">
![]()
display='none'; CodeHighlighter1_96_133_Closed_Text.style.display='none'; CodeHighlighter1_96_133_Open_Image.style.display='inline'; CodeHighlighter1_96_133_Open_Text.style.display='inline';" id="CodeHighlighter1_96_133_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif">
PublicSubNew()SubNew(pAsPoint)
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
_pt=p
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif">
EndSub
![]()
display='none'; CodeHighlighter1_143_181_Open_Text.style.display='none'; CodeHighlighter1_143_181_Closed_Image.style.display='inline'; CodeHighlighter1_143_181_Closed_Text.style.display='inline';" id="CodeHighlighter1_143_181_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif">
![]()
display='none'; CodeHighlighter1_143_181_Closed_Text.style.display='none'; CodeHighlighter1_143_181_Open_Image.style.display='inline'; CodeHighlighter1_143_181_Open_Text.style.display='inline';" id="CodeHighlighter1_143_181_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif">
PublicSubDraw()SubDraw()
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
'somecodeshere.
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif">
EndSub
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif">
EndClass
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/None.gif">
陈述（２），构造
函数不能继承，即，如果要使子类与基类有相同的构造
函数，那么必须在每个子类中都显式的声明与基类构造相同的构造
函数，例如：
![]()
display='none'; CodeHighlighter1_19_187_Open_Text.style.display='none'; CodeHighlighter1_19_187_Closed_Image.style.display='inline'; CodeHighlighter1_19_187_Closed_Text.style.display='inline';" id="CodeHighlighter1_19_187_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif">
![]()
display='none'; CodeHighlighter1_19_187_Closed_Text.style.display='none'; CodeHighlighter1_19_187_Open_Image.style.display='inline'; CodeHighlighter1_19_187_Open_Text.style.display='inline';" id="CodeHighlighter1_19_187_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif">
Public
MustInherit
ClassShape
ClassShape
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
Private_ptAsPoint
![]()
display='none'; CodeHighlighter1_61_98_Open_Text.style.display='none'; CodeHighlighter1_61_98_Closed_Image.style.display='inline'; CodeHighlighter1_61_98_Closed_Text.style.display='inline';" id="CodeHighlighter1_61_98_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif">
![]()
display='none'; CodeHighlighter1_61_98_Closed_Text.style.display='none'; CodeHighlighter1_61_98_Open_Image.style.display='inline'; CodeHighlighter1_61_98_Open_Text.style.display='inline';" id="CodeHighlighter1_61_98_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif">
PublicSubNew()SubNew()
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
'somecodeshere.
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif">
EndSub
![]()
display='none'; CodeHighlighter1_108_145_Open_Text.style.display='none'; CodeHighlighter1_108_145_Closed_Image.style.display='inline'; CodeHighlighter1_108_145_Closed_Text.style.display='inline';" id="CodeHighlighter1_108_145_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif">
![]()
display='none'; CodeHighlighter1_108_145_Closed_Text.style.display='none'; CodeHighlighter1_108_145_Open_Image.style.display='inline'; CodeHighlighter1_108_145_Open_Text.style.display='inline';" id="CodeHighlighter1_108_145_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif">
PublicSubNew()SubNew(pAsPoint)
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
_pt=p
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif">
EndSub
![]()
display='none'; CodeHighlighter1_168_187_Open_Text.style.display='none'; CodeHighlighter1_168_187_Closed_Image.style.display='inline'; CodeHighlighter1_168_187_Closed_Text.style.display='inline';" id="CodeHighlighter1_168_187_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif">
![]()
display='none'; CodeHighlighter1_168_187_Closed_Text.style.display='none'; CodeHighlighter1_168_187_Open_Image.style.display='inline'; CodeHighlighter1_168_187_Open_Text.style.display='inline';" id="CodeHighlighter1_168_187_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif">
PublicMustOverrideSubDraw()SubDraw()
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif">
EndClass
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/None.gif">
![]()
display='none'; CodeHighlighter1_197_370_Open_Text.style.display='none'; CodeHighlighter1_197_370_Closed_Image.style.display='inline'; CodeHighlighter1_197_370_Closed_Text.style.display='inline';" id="CodeHighlighter1_197_370_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif">
![]()
display='none'; CodeHighlighter1_197_370_Closed_Text.style.display='none'; CodeHighlighter1_197_370_Open_Image.style.display='inline'; CodeHighlighter1_197_370_Open_Text.style.display='inline';" id="CodeHighlighter1_197_370_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif">
Public
ClassLine
ClassLine
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
InheritsShape
![]()
display='none'; CodeHighlighter1_232_249_Open_Text.style.display='none'; CodeHighlighter1_232_249_Closed_Image.style.display='inline'; CodeHighlighter1_232_249_Closed_Text.style.display='inline';" id="CodeHighlighter1_232_249_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif">
![]()
display='none'; CodeHighlighter1_232_249_Closed_Text.style.display='none'; CodeHighlighter1_232_249_Open_Image.style.display='inline'; CodeHighlighter1_232_249_Open_Text.style.display='inline';" id="CodeHighlighter1_232_249_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif">
PublicSubNew()SubNew()
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif">
EndSub
![]()
display='none'; CodeHighlighter1_259_302_Open_Text.style.display='none'; CodeHighlighter1_259_302_Closed_Image.style.display='inline'; CodeHighlighter1_259_302_Closed_Text.style.display='inline';" id="CodeHighlighter1_259_302_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif">
![]()
display='none'; CodeHighlighter1_259_302_Closed_Text.style.display='none'; CodeHighlighter1_259_302_Open_Image.style.display='inline'; CodeHighlighter1_259_302_Open_Text.style.display='inline';" id="CodeHighlighter1_259_302_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif">
PublicSubNew()SubNew(pAsPoint)
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
MyBase.New(p)
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif">
EndSub
![]()
display='none'; CodeHighlighter1_322_360_Open_Text.style.display='none'; CodeHighlighter1_322_360_Closed_Image.style.display='inline'; CodeHighlighter1_322_360_Closed_Text.style.display='inline';" id="CodeHighlighter1_322_360_Open_Image" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif">
![]()
display='none'; CodeHighlighter1_322_360_Closed_Text.style.display='none'; CodeHighlighter1_322_360_Open_Image.style.display='inline'; CodeHighlighter1_322_360_Open_Text.style.display='inline';" id="CodeHighlighter1_322_360_Closed_Image" style="display: none" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif">
PublicOverridesSubDraw()SubDraw()
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif">
'somecodeshere.
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif">
EndSub
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif">
EndClass
![]()
PHP?refimg= + this.src)" height="16" src="http://img.jb51.cc/vcimg/static/loading.png" width="11" align="top" src="http://www.cnblogs.com/Images/OutliningIndicators/None.gif">
这一点非常重要而且也很有意义。因为我们往往倾向于认为子类继承了基类所有的
属性和
方法，这往往导致我们的程序出现编译
错误。
综合以上两个陈述，在实际编程中应遵循
一个原则：在类中，无论是基类还是子类，显式地声明所有需要的无参数或带参数构造
函数。遵循这个原则，既有利于提高编译正确
代码的速度，也有利于自己和其他程序员理解
代码。
