今天遇到了Runtime Error 255的错误提示，在网上搜索了好一会儿都没找到比较详细的信息，竟然在Delphi的帮助文件中找到了，收集了一下运行时信息的资料，供日后参考。

Certain errors at runtime cause Delphi programs to display an error message and terminate.

Runtime errors take the form:
Runtime error nnn at xxxxxxxx
where nnn is the runtime error number, and xxxxxxxx is the runtime error address.

Applications that use the SysUtils class map most runtime errors to Exceptions, which allow your application to resolve the error without terminating.

Delphi runtime errors are divided into the following categories:
I/O errors, numbered 100 through 149
Fatal errors, numbered 200 through 255
Operating system errors

I/O error list
The following table lists all I/O errors, numbers, and descriptions.

Number   Name   Description  
100   Disk read error   Reported by Read on a typed file if you attempt to read past the end of the file.  
101   Disk write error   Reported by CloseFile, Write, WriteIn, or Flush if the disk becomes full.  
102   File not assigned   Reported by Reset, Rewrite, Append, Rename, or Erase if the file variable has not been assigned a name through a call to Assign or AssignFile.  
103   File not open   Reported by CloseFile, Read Write, Seek, Eof, FilePos, FileSize, Flush, BlockRead, or BlockWrite if the file is not open.  
104   File not open for input   Reported by Read, Readln, Eof, Eoln, SeekEof, or SeekEoln on a text file if the file is not open for input.  
105   File not open for output   Reported by Write or Writeln on a text file if you do not generate a Console application.  
106   Invalid numeric format   Reported by Read or Readln if a numeric value read from a text file does not conform to the proper numeric format.  

The following table lists all fatal errors, numbers, and mapped exceptions.

Number   Name   Exception  
200   Division by zero   EDivByZero  
201   Range check error   ERangeError  
202   Stack overflow   EStackOverflow  
203   Heap overflow error   EOutOfMemory  
204   Invalid pointer operation   EInvalidPointer  
205   Floating point overflow   EOverflow  
206   Floating point underflow   EUnderflow  
207   Invalid floating point operation   EInvalidOp  
210   Abstract Method Error   EAbstractError  
215   Arithmetic overflow (integer only)   EIntOverflow  
216   Access violation   EAccessViolation  
217   Control-C   EControlC  
218   Privileged instruction   EPrivilege  
219   Invalid typecast   EInvalidCast  
220   Invalid variant typecast   EVariantError  
221   Invalid variant operation   EVariantError  
222   No variant method call dispatcher   EVariantError  
223   Cannot create variant array   EVariantError  
224   Variant does not contain array   EVariantError  
225   Variant array bounds error   EVariantError  
226   TLS initialization error   No exception to map to.  
227   Assertion failed   EAssertionFailed  
228   Interface Cast Error   EIntfCastError  
229   Safecall error   ESafecallException  
230   Unhandled exception   No exception to map to.  
231   Too many nested exceptions   Up to 16 permitted.  
232   Fatal signal raised on a non-Delphi thread   No exception to map to.