Ios [\uu NSPlaceholderArray initWithObjects:计数：]：尝试从对象[0]插入nil对象

我让EagleView Hondling presentFrameBuffer并保存EagleView的屏幕截图，将此照片发送到UIViewController for UIActivityViewController社交网络框架。因此，我保存在

NSUserDefaults

中，然后在UIViewController中检索。但由于未捕获的异常“NSInvalidArgumentException”，我正在终止应用程序，原因：

”***-[\uu NSPlaceholderArray initWithObjects:count:]：尝试从对象[0]插入零对象。

伊格尔维

@property (nonatomic, copy) UIImage * screensht;

   @property (nonatomic, copy) UIButton * save;

伊格尔维

- (BOOL)presentFramebuffer
 {


 if (_takePhotoFlag)

 {


 UIImage *glImage = [self glToUIImage];
 self.screensht = [self createSavableImage:glImage];

  [[NSUserDefaults standardUserDefaults] setObject:UIImagePNGRepresentation(self.screensht) forKey:@"image"];

 UIImageWriteToSavedPhotosAlbum(self.screensht, nil, nil, nil);

 }

 glBindRenderbuffer(GL_RENDERBUFFER, colorRenderbuffer);

 return [context presentRenderbuffer:GL_RENDERBUFFER];
 }

 -(void)save:(id)sender{


 _takePhotoFlag = YES;

 }

Viewcontroller.mm：

- (void)viewDidLoad
 {
 [super viewDidLoad];

 [eaglView.save addTarget:self action:@selector(save:) forControlEvents:UIControlEventTouchUpInside];

 }



 -(void)save:(id)sender{


 NSLog(@"save click");

 NSData* imageData = [[NSUserDefaults standardUserDefaults] objectForKey:@"image"];
 UIImage* image = [UIImage imageWithData:imageData];



 NSArray *activityItems = @[image];

 UIActivityViewController *avc = [[UIActivityViewController alloc] initWithActivityItems:activityItems applicationActivities:nil];
 avc.excludedActivityTypes = [NSArray arrayWithObjects:UIActivityTypePrint, UIActivityTypeCopyToPasteboard, UIActivityTypeAssignToContact, UIActivityTypeSaveToCameraRoll, nil];
 [self presentViewController:avc animated:YES completion:nil];



 }

NSUserDefaults空值：

 [[NSUserDefaults standardUserDefaults] setObject:UIImagePNGRepresentation(self.screensht) forKey:@"image"];

         NSLog(@"nsuserdefauls is %@",[[NSUserDefaults standardUserDefaults] stringForKey:@"image"]);

nsuserdefauls is (null)

---

您将图像存储为NSData对象，但尝试使用

stringForKey

检索图像-这将为零，因为“image”键不包含字符串。你应该使用

NSData *imageData=[[NSUserDefaults standardUserDefaults] objectForKey:@"image"]);
UIImage *image=[UIImage imageWithData:imageData];

---

对我来说，答案是我在打电话

if([_something respondsToSelector:@selector(objectForKey:)])
{
   id a = [_something objectForKey:@"someKey"];
}

---

但是“\u something”是“nil”，这就是我得到崩溃的原因

似乎检索到的图像是零？你检查了吗？你成功保存了图像吗？是的，我可以使用UIImageWriteToSavedPhotosAlbum（self.screensht，nil，nil，nil）将图像保存在相册中；您是否从NSUserDefaults获取图像？我确信

图像

为零。在目标c中，向零发送消息是可以的。您发送objectForKey的东西可能不符合KVO