获取设备信号强度

Question

我正在尝试获取载波、wifi、3g 和 4g 的信号强度（以 dBm 为单位）。

我目前正在使用此代码从状态栏中获取运营商和 wifi，我想知道是否有其他方法或更好的方法？还有，3g 和 4g 怎么买？

UIApplication *app = [UIApplication sharedApplication];
NSArray *subviews = [[[app valueForKey:@"statusBar"] valueForKey:@"foregroundView"] subviews];
NSString *dataNetworkItemView = nil;
NSString *wifiNetworkItemView = nil;

for (id subview in subviews) {
    if([subview isKindOfClass:[NSClassFromString(@"UIStatusBarSignalStrengthItemView") class]]) {
        dataNetworkItemView = subview;
    }
    if([subview isKindOfClass:[NSClassFromString(@"UIStatusBarDataNetworkItemView") class]]) {
        wifiNetworkItemView = subview;
    }
}

int carrierSignalStrength = [[dataNetworkItemView valueForKey:@"signalStrengthRaw"] intValue];
int wifiSignalStrength = [[wifiNetworkItemView valueForKey:@"wifiStrengthRaw"] intValue];

我使用的任何方法是否是私有的都没有关系。

Answer 1

使用 CoreTelephony 和 CTTelephonyCenter 观察者：

#include <CoreTelephony/CoreTelephony.h>

// Event handler
static void SignalStrengthDidChange(CFNotificationCenterRef center, void *observer, CFStringRef name, const void *object, CFDictionaryRef userInfo)
{
    long int raw = 0;
    long int graded = 0;
    long int bars = 0;

    CTIndicatorsGetSignalStrength(&raw, &graded, &bars);

    printf("Signal strength changed! Raw: %li, graded: %li bars: %li\n", raw, graded, bars);
    // Prints something like:
    // Signal strength changed! Raw: -96, graded: 27 bars: 3
}

在另一个函数中注册处理程序：

// Register as a listener to the kCTIndicatorsSignalStrengthNotification notification to be notified when the signal strength changed.
CTTelephonyCenterAddObserver(CTTelephonyCenterGetDefault(), NULL, SignalStrengthDidChange, kCTIndicatorsSignalStrengthNotification, NULL, CFNotificationSuspensionBehaviorCoalesce);

// Get the initial strength.
SignalStrengthDidChange();

CFRunLoopRun();

改编自iPhone Dev Wiki article on CTIndicators。

我相信这些方法不再存在于任何高于 8.4 (?) 的 iOS SDK 中。要访问它们，请创建一个新的标头来外部函数和常量：

#include <CoreFoundation/CoreFoundation.h>

#if __cplusplus
extern "C" {
#endif

#pragma mark - API

    /* This API is a mimic of CFNotificationCenter. */

    CFNotificationCenterRef CTTelephonyCenterGetDefault();
    void CTTelephonyCenterAddObserver(CFNotificationCenterRef center, const void *observer, CFNotificationCallback callBack, CFStringRef name, const void *object, CFNotificationSuspensionBehavior suspensionBehavior);
    void CTTelephonyCenterRemoveObserver(CFNotificationCenterRef center, const void *observer, CFStringRef name, const void *object);
    void CTTelephonyCenterRemoveEveryObserver(CFNotificationCenterRef center, const void *observer);

    void CTIndicatorsGetSignalStrength(long int *raw, long int *graded, long int *bars);

#pragma mark - Definitions

    /* For use with the CoreTelephony notification system. */
    extern CFStringRef kCTIndicatorsSignalStrengthNotification;

#if __cplusplus
}
#endif

Answer 2

我也使用私有 API。但我从（可见）状态栏获得了这个信号强度。

UIApplication *app = [UIApplication sharedApplication];
NSArray *subviews = [[[app valueForKey:@"statusBar"] valueForKey:@"foregroundView"] subviews];
NSString *dataNetworkItemView = nil;
NSString *signalStrengthView = nil;

for (id subview in subviews) {
    NSLog(@"Class - %@", NSStringFromClass([subview class]));

    if([subview isKindOfClass:[NSClassFromString(@"UIStatusBarSignalStrengthItemView") class]]) {
        signalStrengthView = subview;
    }

    if([subview isKindOfClass:[NSClassFromString(@"UIStatusBarDataNetworkItemView") class]]) {
        dataNetworkItemView = subview;
    }
}

int signalStrength = [[signalStrengthView valueForKey:@"signalStrengthRaw"] intValue];
NSLog(@"signal %d", signalStrength);

int wifiStrength = [[dataNetworkItemView valueForKey:@"wifiStrengthRaw"] intValue];
NSLog(@"wifi %d", wifiStrength);

希望这会有所帮助！