Objective c 局部变量变为实例变量后的重构

在将局部变量更改为实例变量后，我的代码遇到了一些问题。具体地说，在更改以下代码的一行后，我在催眠器appdelegate.m文件中的代码遇到了问题：

HypnosisView *view = [[HypnosisView alloc]initWithFrame:screenRect];

到

我已经注释掉了催眠器AppDelegate.m中的错误消息。你能告诉我出了什么问题吗？提前谢谢

催眠器

#import "HypnosisterAppDelegate.h"
#import "HypnosisView.h"

@implementation HypnosisterAppDelegate

@synthesize window = _window;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.

  CGRect screenRect = [[self window]bounds];

  // Create the UIScrollView to have the size of a window, matching its size
  view = [[HypnosisView alloc]initWithFrame:screenRect];
  [scrollView setMinimumZoomScale:1.0];  // Unknown receiver "scrollView"; should it be "UIScrollView"?
  [scrollView setMaximumZoomScale:5.0];  // Unknown receiver "scrollView"; should it be "UIScrollView"?

   //You will get a warning here, ignore it for now
 [scrollView setDelegate:self]; // Unknown receiver "scrollView"; should it be "UIScrollView"?

  [[self window] addSubview:scrollView]; // Unknown receiver "scrollView"; should it be "UIScrollView"?

  //Create the HypnosisView with a frame that is twice the size of the screen
  CGRect bigRect = screenRect;


  HypnosisView *view = [[HypnosisView alloc]initWithFrame:screenRect];

  // Add the HypnosisView as a subview of the scrollView instead of the window
  [scrollView addSubview:view]; // Unknown receiver "scrollView"; should it be "UIScrollView"?



  // Tell the scrollView how big its virtual world is
  [scrollView
   setContentSize:bigRect.size]; // Unknown receiver "scrollView"; should it be "UIScrollView"?

  BOOL success = [view becomeFirstResponder];
  if (success) {
    NSLog(@"HypnosisView became the first responder");
    } else {
    NSLog(@"Could not become the first responder");
  }

  self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    return YES;
}

-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
  return view;
}

@end

催眠视图

#import <Foundation/Foundation.h>

@interface HypnosisView : UIView {

}

@property(nonatomic,strong)UIColor *circleColor;
@end

#导入
@界面催眠视图：UIView{
}
@性质（非原子，强）UIColor*圆环色；
@结束

任何地方都没有名为

scrollView

的变量。我猜（特别是从注释

//创建与窗口大小相匹配的UIScrollView，我自己也看过这本书）您是想创建一个
UIScrollView
：

// not:  view = [[HypnosisView alloc]initWithFrame:screenRect];
// but:
UIScrollView * scrollView = [[UIScrollView alloc] initWithFrame:screenRect];

然后将您的
催眠视图
添加为子视图。
您在哪里创建
滚动视图
？认为这就是问题所在：一定是意外删除了一行：UIScrollView*scrollView=[[UIScrollView alloc]initWithFrame:screenRect]；当我把它加回去的时候，它起作用了。谢谢。谢谢。你想把你的评论放在回答区，这样我可以给你积极的反馈吗？如果你愿意的话。我的评论是为了修辞，但我很高兴它是有帮助的。（如果您愿意，您可以在自己解决问题时回答自己的问题，尽管您需要等待几个小时才能发帖。）
// not:  view = [[HypnosisView alloc]initWithFrame:screenRect];
// but:
UIScrollView * scrollView = [[UIScrollView alloc] initWithFrame:screenRect];