我有一个奇怪的问题,我正在尝试构建一个操作扩展,该扩展将从提供的图像中扫描条形码。这是代码。
override func viewDidLoad() {
super.viewDidLoad()
// Get the item[s] we're handling from the extension context.
// For example, look for an image and place it into an image view.
// Replace this with something appropriate for the type[s] your extension supports.
var imageFound = false
for item: AnyObject in self.extensionContext!.inputItems {
let inputItem = item as NSExtensionItem
for provider: AnyObject in inputItem.attachments! {
let itemProvider = provider as NSItemProvider
if itemProvider.hasItemConformingToTypeIdentifier(kUTTypeImage as NSString) {
// This is an image. We'll load it, then place it in our image view.
weak var weakImageView = self.imageView
itemProvider.loadItemForTypeIdentifier(kUTTypeImage as NSString, options: nil, completionHandler: { (image, error) in
if image != nil {
dispatch_async(dispatch_get_main_queue(),{
if let imageView = weakImageView {
var imageToSet: UIImage? = image as? UIImage
imageView.image = image as? UIImage
}
self.imageToScan = self.imageView.image
self.scanFromImage(self.imageToScan!)
})
}
})
imageFound = true
break
}
}
if (imageFound) {
// We only handle one image, so stop looking for more.
break
}
}
}
现在,每当我尝试获取 UIImage 时,我总是得到 nil,而在图像中我可以看到收到了图像。但是当我尝试从该图像获取 UIImage 时,它总是返回 nil。这是调试的屏幕截图,可能会有所帮助
更新:以下是收到的图像的描述:
图像的打印描述:(NSSecureCoding!) image =
(instance_type = 内置.RawPointer = 0x15d674c0 -> 0x32b6be5c (void
*)0x32b6be70:NSURL)
我使用 Objective C 创建了相同的扩展,它可以工作,但不能快速工作。这是目标 C 代码:
- (void)viewDidLoad {
[super viewDidLoad];
// Get the item[s] we're handling from the extension context.
// For example, look for an image and place it into an image view.
// Replace this with something appropriate for the type[s] your extension supports.
BOOL imageFound = NO;
for (NSExtensionItem *item in self.extensionContext.inputItems) {
for (NSItemProvider *itemProvider in item.attachments) {
if ([itemProvider hasItemConformingToTypeIdentifier:(NSString *)kUTTypeImage]) {
// This is an image. We'll load it, then place it in our image view.
__weak UIImageView *imageView = self.imageView;
[itemProvider loadItemForTypeIdentifier:(NSString *)kUTTypeImage options:nil completionHandler:^(UIImage *image, NSError *error) {
if(image) {
dispatch_async(dispatch_get_main_queue(), ^{
[imageView setImage:image];
imageToScan = image;
[self scanImage:imageToScan];
});
}
}];
imageFound = YES;
break;
}
}
if (imageFound) {
// We only handle one image, so stop looking for more.
break;
}
}
}
我尝试在谷歌上搜索很多,但一无所获。我什至尝试了更改后的代码但不起作用,这是更改后的代码:
itemProvider.loadItemForTypeIdentifier(kUTTypeImage as NSString, options: nil, completionHandler: { (image, error) in
if image != nil {
NSOperationQueue.mainQueue().addOperationWithBlock {
if let imageView = weakImageView {
var imageToSet: UIImage? = image as? UIImage
imageView.image = image as? UIImage
}
self.imageToScan = self.imageView.image
self.scanFromImage(self.imageToScan)
}
}
})
更新:我注意到一件事;如果我创建一个新项目并向其添加操作扩展,则会自动生成相同的代码,除了我在块中添加的几行之外。即使没有更改一行自动生成的代码,imageView.image 也是零。这是斯威夫特的一个错误吗?或者我的 Xcode 应用程序出现一些错误。