ios - React Native Native模块RCTBubblingEventBlock为null

Question

尝试从 native 模块创建回调，但回调未被触发。调用 native 模块的代码似乎工作正常，它打开了扫描应用程序，但似乎根本无法让回调工作

这是我的代码。

@objc (ScanImageView)

class ScanImageViewController: UIViewController, ScanningViewControllerDelegate {

  @objc var onImageCapture: RCTBubblingEventBlock?

  @objc
  static func requiresMainQueueSetup() -> Bool {
    return true
  }

  @objc func startScan(){
    print("What had I created")
    DispatchQueue.main.async {
    self.getTopMostViewController()?.present(ScanningViewController(delegate: self), animated: true)
    }
  }

  func getTopMostViewController() -> UIViewController? {

    var topMostViewController = UIApplication.shared.keyWindow?.rootViewController

    while let presentedViewController = topMostViewController?.presentedViewController {
      topMostViewController = presentedViewController
    }
    return topMostViewController
  }

  func scanningViewControllerDidCancel(_ controller: ScanningViewController)   {
    print("Dismiss called")
    controller.dismiss(animated: true)
  }

  func scanningViewController(_ controller: ScanningViewController, didScan pointCloud: SCPointCloud) {
    print("scanningViewController called")
    print("scanningViewController called")
    if(self.onImageCapture != nil)
    {
      let event = ["startTime": "testing"]
      self.onImageCapture!(event)
      controller.dismiss(animated: true)
    }
  }
}

这是 RCT_EXPORT_METHOD() 宏的代码:

#import "React/RCTBridgeModule.h"
#import "React/RCTViewManager.h"

@interface RCT_EXTERN_MODULE(ScanImageView, UIViewController)
RCT_EXTERN_METHOD(startScan)
RCT_EXPORT_VIEW_PROPERTY(onImageCapture, RCTBubblingEventBlock)
@end

.js 文件只有一个按钮，单击该按钮会调用 startScan 方法，并且似乎工作正常。

<button
    onPress={this.turnOn}
    title="Turn ON "
    color="#FF6347" 
    onImageCapture={this._onImageCapture}/>

根本没有调用 onImageCapture。过去5个小时我一直在努力。任何人都可以指导我正确的方向，了解如何让回调为此工作。

提前致谢。

Answer 1

我找到了使用 sendEvent(withName: "", body: []) 函数的解决方案。必须对我的代码进行以下更改

class ScanImageViewController: UIViewController, ScanningViewControllerDelegate

上面更改为

class ScanImageViewController: RCTEventEmitter, ScanningViewControllerDelegate

还必须添加

@objc
  override func supportedEvents() -> [String]! {
    //Event names
    return ["onImageCapture", "onImageCompleted"]
  }

在 .js 文件中，您需要添加处理程序来监听事件

ScanImageEvents.addListener('onImageCompleted', ({ imageData }) => {
      console.log('onImageCompleted')
    })

希望这对某人有帮助