iphone - 如何根据设备是 3G 还是非 3G 设备来禁止使用应用程序功能？

Question

我想只允许拥有 3G 手机的用户使用特定的 GPS 功能。在允许使用该功能之前，如何在设备上运行检查？

Answer 1

以下代码允许您确定正在使用的确切设备，但我首先会考虑一个事实，即 3G 设备实际上可能无法获得 GPS 锁定，因为这样做的过程非常缓慢并且需要更多或天空的视野不太清晰。

对于 iPhone 3G，此方法的结果将是 iPhone1,2

- (NSString *)deviceModel
{
    NSString *deviceModel = nil;
    char buffer[32];
    size_t length = sizeof(buffer);
    if (sysctlbyname("hw.machine", &buffer, &length, NULL, 0) == 0) {
        deviceModel = [[NSString alloc] initWithCString:buffer encoding:NSASCIIStringEncoding];
    }
    return [deviceModel autorelease];
}

Answer 2

Why would you stop 1g phone users from using location services? If you are near mapped WiFi you can get decent location results even without a GPS on the device.

Instead you should base your choice of what to do around the current location accuracy, if that is a reason why you seek to disable anything.