java中如何访问NetworkRegistrationInfo getNrState()

Question

我有这个功能。但我在这一行遇到错误：|

int nrState = regInfo.getNrState();

留言：

无法解析“NetworkRegistrationInfo”中的“getNrState”方法

有人可以告诉我我犯错了吗？或者我应该以不同的方式做到这一点？

ServiceState serviceState = telephonyManager.getServiceState();
if (serviceState != null) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
        for (NetworkRegistrationInfo regInfo : serviceState.getNetworkRegistrationInfoList()) {
            if (regInfo.getAccessNetworkTechnology() == TelephonyManager.NETWORK_TYPE_NR) {
                int nrState = regInfo.getNrState(); // 👈
                switch (nrState) {
                    case NetworkRegistrationInfo.NR_STATE_NONE:
                        return "Not in NR state";
                    case NetworkRegistrationInfo.NR_STATE_RESTRICTED:
                        return "Restricted NR state";
                    case NetworkRegistrationInfo.NR_STATE_NOT_RESTRICTED:
                        return "Non-restricted NR state";
                    case NetworkRegistrationInfo.NR_STATE_CONNECTED:
                        return "Connected to 5G NR";
                }
            }
        }
    }
}

我需要访问每张 SIM 卡的 getNrState()。

Answer 1

您面临的问题是因为

getNrState()

是在 API 29 中引入的。如果您使用低于此 API 级别的任何设备或模拟器，则该功能不可用。此外，许多设备可能没有完整的 5G 支持，因此该方法在某些设备中无法识别。

您可以执行以下操作：

ServiceState serviceState = telephonyManager.getServiceState();
 if (serviceState != null) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) { 

           // Ensure Android 11 or higher        
            List<NetworkRegistrationInfo> regInfoList = serviceState.getNetworkRegistrationInfoList();        
            if (regInfoList != null) {
            for (NetworkRegistrationInfo regInfo : regInfoList) {
                if (regInfo.getAccessNetworkTechnology() == TelephonyManager.NETWORK_TYPE_NR) {

                    // Ensure API level compatibility for getNrState()
                      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
                        int nrState = regInfo.getNrState(); // Only available on API 29+switch (nrState) {
                            case NetworkRegistrationInfo.NR_STATE_NONE:
                                return "Not in NR state";
                            case NetworkRegistrationInfo.NR_STATE_RESTRICTED:
                                return "Restricted NR state";
                            case NetworkRegistrationInfo.NR_STATE_NOT_RESTRICTED:
                                return "Non-restricted NR state";
                            case NetworkRegistrationInfo.NR_STATE_CONNECTED:
                                return "Connected to 5G NR";
                        }
                    } else {
                        return "getNrState() not available on this Android version";
                    }
                }
            }
        }
    }
}