反应本地和目标C代表

Question

我对用本机代码反应本机和桥接机制很不熟悉，尤其是当框架有委托时。假设我正在尝试桥接以下框架：

@protocol BRPtouchNetworkDelegate;

@class PLNetworkModule;

@interface BRPtouchNetworkManager : NSObject <NSNetServiceBrowserDelegate,NSNetServiceDelegate>


@property(retain, nonatomic) NSMutableArray* registeredPrinterNames;
@property(assign, nonatomic) BOOL isEnableIPv6Search;


- (int)startSearch: (int)searchTime;
- (NSArray*)getPrinterNetInfo;

- (BOOL)setPrinterNames:(NSArray*)strPrinterNames;
- (BOOL)setPrinterName:(NSString*)strPrinterName;

- (id)initWithPrinterNames:(NSArray*)strPrinterNames;
- (id)initWithPrinterName:(NSString*)strPrinterName;

@property (nonatomic, assign) id <BRPtouchNetworkDelegate> delegate;

@end

@protocol BRPtouchNetworkDelegate <NSObject>

-(void) didFinishSearch:(id)sender;

@end

以下是我实现的桥接模块：

RCTBRPtouchNetworkManager。h

#import <React/RCTBridgeModule.h>
#import <BRPtouchPrinterKit/BRPtouchPrinterKit.h>

@interface RCTBRPtouchNetworkManager : NSObject <RCTBridgeModule, BRPtouchNetworkDelegate>
@end

RCTBRPtouchNetworkManager。m

#import "RCTBRPtouchNetworkManager.h"
#import <BRPtouchPrinterKit/BRPtouchPrinterKit.h>
#import <React/RCTLog.h>

@implementation RCTBRPtouchNetworkManager {
  BRPtouchNetworkManager  *_networkManager;
}

RCT_EXPORT_MODULE();

RCT_EXPORT_METHOD(addEvent:(NSString *)name location:(NSString *)location)
{
  RCTLogInfo(@"Pretending to create an event %@ at %@", name, location); //a dummy method to test the bridge
}

RCT_EXPORT_METHOD(startSearchWithTimeout:(int)time) {
  RCTLogInfo(@"Bridge started search with time %d", time);

  _networkManager = [[BRPtouchNetworkManager alloc] init];
  _networkManager.delegate = self; //I'm setting delegate here
  _networkManager.isEnableIPv6Search = NO;
  NSString *  path = [[NSBundle mainBundle] pathForResource:@"PrinterList" ofType:@"plist"];
  if( path )
  {
    NSDictionary *printerDict = [NSDictionary dictionaryWithContentsOfFile:path];
    NSArray *printerList = [[NSArray alloc] initWithArray:printerDict.allKeys];
    [_networkManager setPrinterNames:printerList];
  } else {
    RCTLogInfo(@"PrinterList path not found");
  }

  //  Start printer search
  [_networkManager startSearch: 5.0];

}

- (void)didFinishSearch:(id)sender {
  NSLog(@"didFinishedSearch"); //this delegate method is not called
}

@end

我可以很容易地调用虚拟方法，并在日志中查看结果。但是，从未调用委托方法didFinishSearch（）。我从javascript中调用它，如下所示：

componentDidMount() {
    let networkManager = NativeModules.BRPtouchNetworkManager;
    networkManager.startSearchWithTimeout(5.0);
}

我有什么遗漏吗？我是否正确地实现了委托？这种功能是否可能（似乎不可能，因为委托方法被iOS社区使用了很长时间）。非常感谢您的帮助。

编辑

我发现在我的bridge manager文件中添加以下内容会导致该代表被解雇（多亏了这篇文章）

- (dispatch_queue_t)methodQueue
{
    return dispatch_get_main_queue();
}

然而，即使这解决了问题，我还是想对这里发生的事情有一个更技术性的理解，因为我似乎不能完全理解它。谢谢你

Answer 1

我知道这不是对这篇文章的回答，而是为了让你对dispatch\u get\u main\u queue（）有更多的技术理解；将委托方法响应放在主线程上。由于JS是单线程的，因此后台线程上的任何进程都不可见。