[__NSPlaceholderArray initWithObjects:count:]：尝试从objects[0]插入nil对象
[__NSPlaceholderArray initWithObjects:count:]：尝试从objects[0]插入nil对象
提问于 2014-06-16 14:14:25
我让EAGLView管理presentFrameBuffer并保存来自EAGLView的截图，将此截图发送到UIActivityViewController社交网络框架的UIViewController。因此，我先保存在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：'*** -[__NSPlaceholderArray initWithObjects:count:]: attempt to insert nil object from objects[0]'
EAGLView.h
@property (nonatomic, copy) UIImage * screensht;
@property (nonatomic, copy) UIButton * save;EAGLview.mm
- (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为空：
[[NSUserDefaults standardUserDefaults] setObject:UIImagePNGRepresentation(self.screensht) forKey:@"image"];
NSLog(@"nsuserdefauls is %@",[[NSUserDefaults standardUserDefaults] stringForKey:@"image"]);
nsuserdefauls is (null)回答 2
Stack Overflow用户
发布于 2014-06-16 17:14:06
您正在将图像存储为一个NSData对象，但是尝试使用stringForKey检索它-这将为空，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];Stack Overflow用户
发布于 2014-11-23 07:20:59
对我来说，答案是我打电话给
if([_something respondsToSelector:@selector(objectForKey:)])
{
id a = [_something objectForKey:@"someKey"];
}但是'_something‘是'nil’，这就是我崩溃的原因
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/24237578
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