错误 1 “Tetris.BlockInfo.GetIdStr()”: 并非所有的代码路径都返回值 C:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\Projects\Tetris\Tetris\BlockInfo.cs 39 23 Tetris

public string GetIdStr()
{
StringBuilder s = new StringBuilder(25);
foreach (bool b in _id)
{
s.Append(b ? "1" : "0");
}
}