flutter + getx 电商商城项目

# MTBBarcodeScanner [](http://cocoadocs.org/docsets/MTBBarcodeScanner) [](http://cocoadocs.org/docsets/MTBBarcodeScanner) [](http://cocoadocs.org/docsets/MTBBarcodeScanner) [](https://github.com/Carthage/Carthage) A lightweight, easy-to-use barcode scanning library for iOS 8+. This library is built on top of Apple's excellent AVFoundation framework, and will continue to receive updates as Apple releases them. With this library you can: - Supply a custom UIView for displaying camera input - Read any number of barcodes before stopping - Read multiple codes on the screen at the same time (2D barcodes only) - Easily read codes with a block, including the string value and position in the preview - Easily flip from the back to the front camera - Toggle the device's torch on and off - Freeze and unfreeze capture to display a still image from the camera See demo project for examples of capturing one code, multiple codes, or highlighting codes as valid or invalid in the live preview. --- <img src="https://raw.githubusercontent.com/mikebuss/MTBBarcodeScanner/develop/Assets/MTBBarcodeScanner.png" width=100% height=100%> #### Sample Barcodes <img src="https://raw.githubusercontent.com/mikebuss/MTBBarcodeScanner/develop/Assets/sample-barcodes.png" width=50% height=50%> --- ## Installation ### CocoaPods MTBBarcodeScanner can be installed via [CocoaPods](http://cocoapods.org) by adding the following line to your Podfile: `pod "MTBBarcodeScanner"` ### Carthage [Carthage](https://github.com/Carthage/Carthage) is a decentralized dependency manager that builds your dependencies and provides you with binary frameworks. You can install Carthage with [Homebrew](http://brew.sh/) using the following command: ```bash $ brew update $ brew install carthage ``` To integrate MTBBarcodeScanner into your Xcode project using Carthage, specify it in your `Cartfile`: ```ogdl github "mikebuss/MTBBarcodeScanner" ``` Run `carthage update` to build the framework and drag the built `MTBBarcodeScanner.framework` into your Xcode project. ### Manual If you'd prefer not to use a dependency manager, you can download [these two files](https://github.com/mikebuss/MTBBarcodeScanner/tree/master/Classes/ios/Scanners) and add them to your project: [`MTBBarcodeScanner.h`](https://github.com/mikebuss/MTBBarcodeScanner/blob/master/Classes/ios/Scanners/MTBBarcodeScanner.h) [`MTBBarcodeScanner.m`](https://github.com/mikebuss/MTBBarcodeScanner/blob/master/Classes/ios/Scanners/MTBBarcodeScanner.m) --- ## Usage in Objective-C Projects To import the library: `#import "MTBBarcodeScanner.h"` #### Initialization To initialize an instance of `MTBBarcodeScanner`: ```objective-c scanner = [[MTBBarcodeScanner alloc] initWithPreviewView:self.previewView]; ``` Where `previewView` is the `UIView` in which the camera input will be displayed. If you only want to scan for certain MetaObjectTypes, you can initialize with the `initWithMetadataObjectTypes:previewView:` method: ```objective-c s = [[MTBBarcodeScanner alloc] initWithMetadataObjectTypes:@[AVMetadataObjectTypeQRCode] previewView:self.previewView]; ``` #### iOS 10 and later If you are using the `MTBBarcodeScanner` library on iOS 10 and later, you need to include the following `Info.plist` key in order to request camera access or the application will crash: ```xml <key>NSCameraUsageDescription</key> <string>Can we access your camera in order to scan barcodes?</string> ``` Of course you can also set your own (localized) message here. To find out more about privacy-keys in iOS, check the [official Apple documentation](https://developer.apple.com/library/content/documentation/General/Reference/InfoPlistKeyReference/Articles/CocoaKeys.html). #### Scanning To read the first code and stop scanning: **Note:** To avoid a delay in the camera feed, start scanning in `viewDidAppear` and not `viewDidLoad`. ```objective-c [MTBBarcodeScanner requestCameraPermissionWithSuccess:^(BOOL success) { if (success) { NSError *error = nil; [self.scanner startScanningWithResultBlock:^(NSArray *codes) { AVMetadataMachineReadableCodeObject *code = [codes firstObject]; NSLog(@"Found code: %@", code.stringValue); [self.scanner stopScanning]; } error:&error]; } else { // The user denied access to the camera } }]; ``` If the camera is pointed at more than one 2-dimensional code, you can read all of them: ```objective-c NSError *error = nil; [self.scanner startScanningWithResultBlock:^(NSArray *codes) { for (AVMetadataMachineReadableCodeObject *code in codes) { NSLog(@"Found code: %@", code.stringValue); } [self.scanner stopScanning]; } error:&error]; ``` **Note:** This only applies to 2-dimensional barcodes as 1-dimensional barcodes can only be read one at a time. See [relevant Apple document](https://developer.apple.com/library/ios/technotes/tn2325/_index.html). To continuously read and only output unique codes: ```objective-c NSError *error = nil; [self.scanner startScanningWithResultBlock:^(NSArray *codes) { for (AVMetadataMachineReadableCodeObject *code in codes) { if ([self.uniqueCodes indexOfObject:code.stringValue] == NSNotFound) { [self.uniqueCodes addObject:code.stringValue]; NSLog(@"Found unique code: %@", code.stringValue); } } } error:&error]; ``` #### Callback Blocks An alternative way to setup MTBBarcodeScanner is to configure the blocks directly, like so: ```objective-c self.scanner.didStartScanningBlock = ^{ NSLog(@"The scanner started scanning! We can now hide any activity spinners."); }; self.scanner.resultBlock = ^(NSArray *codes){ NSLog(@"Found these codes: %@", codes); }; self.scanner.didTapToFocusBlock = ^(CGPoint point){ NSLog(@"The user tapped the screen to focus. \ Here we could present a view at %@", NSStringFromCGPoint(point)); }; [self.scanner startScanning]; ``` This is useful if you would like to present a spinner while MTBBarcodeScanner is initializing. If you would like to reference `self` in one of these blocks, remember to use a weak reference to avoid a retain cycle: ```objective-c __weak MyViewController *weakSelf = self; self.scanner.resultBlock = ^(NSArray *codes){ [weakSelf drawOverlaysOnCodes:codes]; }; ``` --- ## Usage in Swift 3+ Projects See the `SwiftExampleViewController.swift` file in the repository for a working example of this. ```swift import UIKit import MTBBarcodeScanner class SwiftExampleViewController: UIViewController { @IBOutlet var previewView: UIView! var scanner: MTBBarcodeScanner? override func viewDidLoad() { super.viewDidLoad() scanner = MTBBarcodeScanner(previewView: previewView) } override func viewDidAppear(_ animated: Bool) { super.viewDidAppear(animated) MTBBarcodeScanner.requestCameraPermission(success: { success in if success { do { try self.scanner?.startScanning(resultBlock: { codes in if let codes = codes { for code in codes { let stringValue = code.stringValue! print("Found code: \(stringValue)") } } }) } catch { NSLog("Unable to start scanning") } } else { UIAlertView(title: "Scanning Unavailable", message: "This app does no