UIImage返回零

我将创build一个UIImage但如果我debugging该方法返回nil 。 我希望有人知道我必须做什么。

我的代码：

返回nil：

 UIImage *image1 = imgView.image; 

整个代码块：

 UIImage *image1 = imgView.image; NSString *cachedFolderPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0]; NSString *cachedImagePath = [cachedFolderPath stringByAppendingPathComponent:@"image1.png"]; [UIImagePNGRepresentation(image1) writeToFile:cachedImagePath atomically:YES]; 

更新：

 - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{ if (picker.sourceType == UIImagePickerControllerSourceTypeCamera) { toolbar.hidden = NO; UIImage *image1 = imgView.image; NSString *cachedFolderPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0]; NSString *cachedImagePath = [cachedFolderPath stringByAppendingPathComponent:@"image1.png"]; [UIImagePNGRepresentation(image1) writeToFile:cachedImagePath atomically:YES]; } if (picker.sourceType == UIImagePickerControllerSourceTypePhotoLibrary) { toolbar.hidden = NO; UIImage *image1 = imgView.image; NSString *cachedFolderPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0]; NSString *cachedImagePath = [cachedFolderPath stringByAppendingPathComponent:@"image1.png"]; [UIImagePNGRepresentation(image1) writeToFile:cachedImagePath atomically:YES]; } if (picker.sourceType == UIImagePickerControllerSourceTypeSavedPhotosAlbum) { toolbar.hidden = NO; UIImage *image1 = imgView.image; NSString *cachedFolderPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0]; NSString *cachedImagePath = [cachedFolderPath stringByAppendingPathComponent:@"image1.png"]; [UIImagePNGRepresentation(image1) writeToFile:cachedImagePath atomically:YES]; } else{ toolbar.hidden = NO; } imgView.image = [info objectForKey:@"UIImagePickerControllerEditedImage"]; [self dismissViewControllerAnimated:YES completion:nil]; } 

Answer 1

我认为你正在尝试使用imgView.image属性，甚至在你设置它之前。

imageView.image正在设置此行

 imgView.image = [info objectForKey:@"UIImagePickerControllerEditedImage"]; 

将该行移到方法的开头。 喜欢这个

 - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{ imgView.image = [info objectForKey:@"UIImagePickerControllerEditedImage"]; if (picker.sourceType == UIImagePickerControllerSourceTypeCamera) { toolbar.hidden = NO; UIImage *image1 = imgView.image; NSString *cachedFolderPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0]; NSString *cachedImagePath = [cachedFolderPath stringByAppendingPathComponent:@"image1.png"]; [UIImagePNGRepresentation(image1) writeToFile:cachedImagePath atomically:YES]; } 

Answer 2

你第一次设置imgView.image的值接近imagePickerController:didFinishPickingMediaWithInfo:的结尾imagePickerController:didFinishPickingMediaWithInfo: 因此，第一次调用这个方法时， imgView.image将会是nil直到它被设置为：

 imgView.image = [info objectForKey:@"UIImagePickerControllerEditedImage"]; 

Answer 3

对不起，要跳过阅读你的代码，只是发布什么对我有用。

 - (UIImage *) getImage{ NSString *pathAndFileName = [[NSBundle mainBundle] pathForResource:@"somefile.png" ofType:nil]; if ([[NSFileManager defaultManager] fileExistsAtPath:pathAndFileName]) { return [UIImage imageNamed:@"somefile.png"]; } else{ NSString *t = [self pathToImageInCache:@"somefile.png"]; if ([[NSFileManager defaultManager] fileExistsAtPath:t]){ NSLog(@"fiel exists"); return [[UIImage alloc]initWithContentsOfFile:t]; } else{ NSLog(@"fiel does not exists"); } } return nil; } - (NSString *) pathToImageInCache: (NSString *) imageName{ NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; documentsDirectory = [documentsDirectory stringByAppendingPathComponent:@""]; NSString *URLImg = [documentsDirectory stringByAppendingPathComponent:imageName]; return URLImg; }