static public GoBackCmd Ensure(StackConductor <T> holder, ref WeakReference <GoBackCmd> cmdRef) { GoBackCmd cmd; if (cmdRef == null) { cmdRef = cmd = new GoBackCmd(holder); } else if ((cmd = cmdRef.Target) == null) { cmdRef.Target = cmd = new GoBackCmd(holder); } return(cmd); }
public GoBackCmd(StackConductor <T> c) { _c = c; }