vb.net中有这样的相同功能的语法吗?

[sutter]

ExeConfigurationFileMap file = new ExeConfigurationFileMap();
file.ExeConfigFilename = "test.config";
Configuration config = ConfigurationManager.OpenMappedExeConfiguration(file, ConfigurationUserLevel.None);

ConfigSectionData data = config.SectionGroups["group1"].Sections["add"] as ConfigSectionData;


说明 ConfigSectionData 是一个自定义类,特别是最后一句：ConfigSectionData data = config.SectionGroups["group1"].Sections["add"] as ConfigSectionData; 这个等号后面还可以 as ,这是什么意思啊,vb.net中有这样的相同功能的语法吗？

[saucer]

no, in VB.NET, you have to use CType or DirectCast

the safest approach is to check the type first

if TypeOf config.SectionGroups("group1").Sections("add") Is ConfigSectionData then
'....
end if

[sutter]

怎么调试时 提示 config.SectionGroups("group1").Sections("add") 未将对象引用到实例

[saucer]

if config.SectionGroups("group1").Sections("add") is nothing then
'such group/section doesn't exist
elseif TypeOf config.SectionGroups("group1").Sections("add") Is ConfigSectionData then
'....
end if

[copall]

发现3个钻石...