//获取键盘第一响应者
UIWindow*keyWindow = [[UIApplicationsharedApplication]keyWindow];
UIView*firstResponder = [keyWindowperformSelector:@selector(firstResponder)];
//获取键盘第一响应者
UIWindow*keyWindow = [[UIApplicationsharedApplication]keyWindow];
UIView*firstResponder = [keyWindowperformSelector:@selector(firstResponder)];