我已经开始为iOS 8.3开发一个非苹果商店应用程序，用于测量并返回以dB为单位的接收信号强度指示器（RSSI）值。我可以访问一个名为VAFieldTest的Xcode项目的git存储库，该项目使用Core Telephony框架来访问诸如Cell ID，service mnc，RSSI等信息。但是，项目的生成失败并返回以下错误：
Ld /Users/rajesh/Library/Developer/Xcode/DerivedData/VAFieldTest-dmyrokwehbyuqcauvwpiouivlnqy/Build/Products/Debug-iphonesimulator/VAFieldTest.app/VAFieldTest normal i386
cd /Users/rajesh/Documents/VAFieldTest
export IPHONEOS_DEPLOYMENT_TARGET=4.0
export PATH="/Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode-beta.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Applications/Xcode-beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch i386 -isysroot /Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.4.sdk -L/Users/rajesh/Library/Developer/Xcode/DerivedData/VAFieldTest-dmyrokwehbyuqcauvwpiouivlnqy/Build/Products/Debug-iphonesimulator -F/Users/rajesh/Library/Developer/Xcode/DerivedData/VAFieldTest-dmyrokwehbyuqcauvwpiouivlnqy/Build/Products/Debug-iphonesimulator -F/Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.4.sdk/System/Library/PrivateFrameworks -filelist /Users/rajesh/Library/Developer/Xcode/DerivedData/VAFieldTest-dmyrokwehbyuqcauvwpiouivlnqy/Build/Intermediates/VAFieldTest.build/Debug-iphonesimulator/VAFieldTest.build/Objects-normal/i386/VAFieldTest.LinkFileList -Xlinker -objc_abi_version -Xlinker 2 -fobjc-link-runtime -Xlinker -no_implicit_dylibs -mios-simulator-version-min=4.0 -framework Foundation -framework UIKit -framework CoreGraphics -framework CoreTelephony -weak_framework VoiceServices -Xlinker -dependency_info -Xlinker /Users/rajesh/Library/Developer/Xcode/DerivedData/VAFieldTest-dmyrokwehbyuqcauvwpiouivlnqy/Build/Intermediates/VAFieldTest.build/Debug-iphonesimulator/VAFieldTest.build/Objects-normal/i386/VAFieldTest_dependency_info.dat -o /Users/rajesh/Library/Developer/Xcode/DerivedData/VAFieldTest-dmyrokwehbyuqcauvwpiouivlnqy/Build/Products/Debug-iphonesimulator/VAFieldTest.app/VAFieldTest
ld: -pie can only be used when targeting iOS 4.2 or later
clang: error: linker command failed with exit code 1 (use -v to see invocation)
起初我认为这是由于新库的链接，但经过检查，构建依赖项已经包含在内，它没有帮助。我想自己调用核心电话方法，但官方文档没有列出在iOS 8.3中访问这些核心功能的方法。列出的方法在开发人员文档库中可用，不包含所需的方法。
如何在 iOS 8.3 中获取 RSSI 值？我使用的是Xcode 6.4测试版。
您可以使用以下命令获得信号强度：
UIApplication *app = [UIApplication sharedApplication];
NSArray *subviews = [[[app valueForKey:@"statusBar"] valueForKey:@"foregroundView"] subviews];
NSString *dataNetworkItemView = nil;
for (id subview in subviews) {
if([subview isKindOfClass:[NSClassFromString(@"UIStatusBarSignalStrengthItemView") class]]) {
dataNetworkItemView = subview;
break;
}
}
int signalStrength = [[dataNetworkItemView valueForKey:@"signalStrengthRaw"] intValue];
NSLog(@"signal %d", signalStrength);
这不再可能，显然是修补漏洞的副作用。获取CellID，LAC，...在 iOS 8.3 上