iOS 开发：实时监测网速（下载/上传速度） - Objective-C 代码示例

以下是使用 Objective-C 代码实时监测网速下载上传速度的示例：

首先，需要引入 SystemConfiguration 和 CoreFoundation 框架：

#import <SystemConfiguration/SystemConfiguration.h>
#import <CoreFoundation/CoreFoundation.h>

然后，创建一个用于实时监测网速的类，例如 NetworkSpeedMonitor：

@interface NetworkSpeedMonitor : NSObject

@property (nonatomic, copy) void (^networkSpeedUpdateBlock)(float downloadSpeed, float uploadSpeed);

+ (instancetype)sharedInstance;
- (void)startMonitoring;
- (void)stopMonitoring;

@end

在 NetworkSpeedMonitor.m 文件中，实现以下方法：

#import "NetworkSpeedMonitor.h"

#include <arpa/inet.h>
#include <net/if.h>
#include <ifaddrs.h>
#include <net/if_dl.h>
#include <net/ethernet.h>
#include <netinet/in.h>
#include <net/if_types.h>

@interface NetworkSpeedMonitor ()

@property (nonatomic, strong) NSTimer *timer;
@property (nonatomic, assign) uint32_t lastUploadedBytes;
@property (nonatomic, assign) uint32_t lastDownloadedBytes;

@end

@implementation NetworkSpeedMonitor

+ (instancetype)sharedInstance {
    static NetworkSpeedMonitor *sharedInstance = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sharedInstance = [[NetworkSpeedMonitor alloc] init];
    });
    return sharedInstance;
}

- (void)startMonitoring {
    self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(updateNetworkSpeed) userInfo:nil repeats:YES];
    [[NSRunLoop currentRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
    [self.timer fire];
}

- (void)stopMonitoring {
    [self.timer invalidate];
    self.timer = nil;
}

- (void)updateNetworkSpeed {
    struct ifaddrs *ifa_list = 0, *ifa;
    if (getifaddrs(&ifa_list) == -1) {
        return;
    }
    
    uint32_t totalSent = 0;
    uint32_t totalReceived = 0;
    
    for (ifa = ifa_list; ifa; ifa = ifa->ifa_next) {
        if ((ifa->ifa_flags & IFF_UP) && (ifa->ifa_flags & IFF_RUNNING) && !(ifa->ifa_flags & IFF_LOOPBACK) && (ifa->ifa_data != 0)) {
            struct if_data* if_data = (struct if_data*)ifa->ifa_data;
            totalSent += if_data->ifi_obytes;
            totalReceived += if_data->ifi_ibytes;
        }
    }
    
    freeifaddrs(ifa_list);
    
    if (self.lastUploadedBytes != 0 && self.lastDownloadedBytes != 0) {
        float uploadSpeed = (totalSent - self.lastUploadedBytes) / 1024.0;
        float downloadSpeed = (totalReceived - self.lastDownloadedBytes) / 1024.0;
        
        if (self.networkSpeedUpdateBlock) {
            self.networkSpeedUpdateBlock(downloadSpeed, uploadSpeed);
        }
    }
    
    self.lastUploadedBytes = totalSent;
    self.lastDownloadedBytes = totalReceived;
}

@end

使用时，在需要监测网速的地方调用以下代码：

NetworkSpeedMonitor *networkSpeedMonitor = [NetworkSpeedMonitor sharedInstance];
[networkSpeedMonitor startMonitoring];

networkSpeedMonitor.networkSpeedUpdateBlock = ^(float downloadSpeed, float uploadSpeed) {
    NSLog('Download speed: %.2f KB/s', downloadSpeed);
    NSLog('Upload speed: %.2f KB/s', uploadSpeed);
};

// 停止监测网速
[networkSpeedMonitor stopMonitoring];

这样，就可以实时监测网速的下载和上传速度了。