如何转换标志"?" 在c#到vb.net?

1 c# vb.net operators

我正在尝试将c#代码转换为vb.net,但我很难转换符号"?" 在c#到vb.net.这里我的代码转换

 public audit_trail Mapper(IDataReader rdr)
 {
      audit_trail audit_trail = new audit_trail();
      audit_trail.Log_id = rdr["Log_id"] is DBNull ? 0 : (int)rdr["Log_id"];            
      audit_trail.Host = rdr["Host"] is DBNull ? string.Empty : (string)rdr["Host"];
      return audit_trail;
 } 
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如何转换标志"?" 到vb.net ??

我想转换

  audit_trail.Host = rdr["Host"] is DBNull ? string.Empty : (string)rdr["Host"];
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喜欢的东西

if rdr["Host"] is DBNull.Value then
  audit_trail.Host =  string.Empty 
else 
  audit_trail.Host = rdr["Host"]
end if
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但代码太长,代码行太多..你们有没有想法转换为短代码?

Woo*_*ble 6

三元运算符的可视基本语法是If([condition,] op1, op2).