Question

如何通过修改build.prop文件来修改Android 首选网络模式默认值

Answer 1

修改系统属性：ro.telephony.default_network
修改说明：
可连续给两个值（如4，1），卡1用的是4，卡2用的是1。数字代表的意义见下方的相关代码片段。

相关源码位置：
frameworks/base/telephony/java/com/android/internal/telephony/RILConstants.java
frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java

相关代码片段：

/* NETWORK_MODE_* See ril.h RIL_REQUEST_SET_PREFERRED_NETWORK_TYPE */

int NETWORK_MODE_WCDMA_PREF = 0; /* GSM/WCDMA (WCDMA preferred) */

int NETWORK_MODE_GSM_ONLY = 1; /* GSM only */

int NETWORK_MODE_WCDMA_ONLY = 2; /* WCDMA only */

int NETWORK_MODE_GSM_UMTS = 3; /* GSM/WCDMA (auto mode, according to PRL)

AVAILABLE Application Settings menu*/

int NETWORK_MODE_CDMA = 4; /* CDMA and EvDo (auto mode, according to PRL)

AVAILABLE Application Settings menu*/

int NETWORK_MODE_CDMA_NO_EVDO = 5; /* CDMA only */

int NETWORK_MODE_EVDO_NO_CDMA = 6; /* EvDo only */

int NETWORK_MODE_GLOBAL = 7; /* GSM/WCDMA, CDMA, and EvDo (auto mode, according to PRL)

AVAILABLE Application Settings menu*/

int NETWORK_MODE_LTE_CDMA_EVDO = 8; /* LTE, CDMA and EvDo */

int NETWORK_MODE_LTE_GSM_WCDMA = 9; /* LTE, GSM/WCDMA */

int NETWORK_MODE_LTE_CMDA_EVDO_GSM_WCDMA = 10; /* LTE, CDMA, EvDo, GSM/WCDMA */

int NETWORK_MODE_LTE_ONLY = 11; /* LTE Only mode. */

int NETWORK_MODE_LTE_WCDMA = 12; /* LTE/WCDMA */

int NETWORK_MODE_TD_SCDMA_ONLY = 13; /* TD-SCDMA only */

int NETWORK_MODE_TD_SCDMA_WCDMA = 14; /* TD-SCDMA and WCDMA */

int NETWORK_MODE_TD_SCDMA_LTE = 15; /* TD-SCDMA and LTE */

int NETWORK_MODE_TD_SCDMA_GSM = 16; /* TD-SCDMA and GSM */

int NETWORK_MODE_TD_SCDMA_GSM_LTE = 17; /* TD-SCDMA,GSM and LTE */

int NETWORK_MODE_TD_SCDMA_GSM_WCDMA = 18; /* TD-SCDMA, GSM/WCDMA */

int NETWORK_MODE_TD_SCDMA_WCDMA_LTE = 19; /* TD-SCDMA, WCDMA and LTE */

int NETWORK_MODE_TD_SCDMA_GSM_WCDMA_LTE = 20; /* TD-SCDMA, GSM/WCDMA and LTE */

int NETWORK_MODE_TD_SCDMA_CDMA_EVDO_GSM_WCDMA = 21; /*TD-SCDMA,EvDo,CDMA,GSM/WCDMA*/

int NETWORK_MODE_TD_SCDMA_LTE_CDMA_EVDO_GSM_WCDMA = 22; /* TD-SCDMA/LTE/GSM/WCDMA, CDMA, and

EvDo */
复制代码
// Set the preferred network mode

int defaultNetworkType = RILConstants.PREFERRED_NETWORK_MODE;

int numPhones = MSimTelephonyManager.getDefault().getPhoneCount();

String networkMode = SystemProperties.get("ro.telephony.default_network");

if (networkMode != null) {

if (numPhones == MSimConstants.MAX_PHONE_COUNT_SINGLE_SIM) {

loadSetting(

stmt,

Settings.Global.PREFERRED_NETWORK_MODE,

MSimTelephonyManager.getTelephonyProperty(

"ro.telephony.default_network", 0,

Integer.toString(defaultNetworkType)));

} else {

loadSetting(stmt, Settings.Global.PREFERRED_NETWORK_MODE, networkMode);

}

} else {

StringBuilder sb = new StringBuilder(defaultNetworkType);

for (int i = 0; i < numPhones - 1; i++) {

sb.append(",");

sb.append(RILConstants.NETWORK_MODE_GSM_ONLY);

}

loadSetting(stmt, Settings.Global.PREFERRED_NETWORK_MODE, sb.toString());