iOS在Swift(核心电话)中获得信号强度

Question

我是iOS新手，正在学习用Swift编程。我的应用程序需要测量信号强度。我发现这个代码在Objective-C/C上工作，需要一些帮助来实现Swift。这是我得到的。希望有人能帮我完成它。

OBJECTIVE - C

    int getSignalStrength()
    {
       void *libHandle = dlopen("/System/Library/Frameworks/CoreTelephony.framework/CoreTelephony", RTLD_LAZY);
       int (*CTGetSignalStrength)();
       CTGetSignalStrength = dlsym(libHandle, "CTGetSignalStrength");
       if( CTGetSignalStrength == NULL) NSLog(@"Could not find CTGetSignalStrength");
       int result = CTGetSignalStrength();
       dlclose(libHandle);
       return result;
    }

迅速

    func getSignalStrength()->Int{
       var result : Int! = 0
       let libHandle = dlopen ("/System/Library/Frameworks/CoreTelephony.framework/CoreTelephony", RTD_LAZY)
       ** help **
       var CTGetSignalStrength = dlsym(libHandle, "CTGetSignalStrength")
       if (CTGetSignalStrength != nil){
           result = CTGetSignalStrength()
       }
       dlclose(libHandle)
       return result
    }

Answer 1

不要使用dlopen来加载coreelephony。在Swift文件的顶部使用import CoreTelephony。然后像使用其他函数一样使用CTGetSignalStrength。

Answer 2

Swift 3 Solution

import CoreTelephony
import Darwin
    static func getSignalStrength()->Int{
        var result : Int = 0
        //int CTGetSignalStrength();
        let libHandle = dlopen ("/System/Library/Frameworks/CoreTelephony.framework/CoreTelephony", RTLD_NOW)
        let CTGetSignalStrength2 = dlsym(libHandle, "CTGetSignalStrength")
        typealias CFunction = @convention(c) () -> Int
        if (CTGetSignalStrength2 != nil) {
            let fun = unsafeBitCast(CTGetSignalStrength2!, to: CFunction.self)
            let result = fun()
            return result;
            print("!!!!result (result)")
        } 
     return -1
 }