AndroidCellularSignalStrength.java 文件源码

/**
 * @return the signal level from {@link cellInfo}. Returns {@link
 * CellularSignalStrengthError#ERROR_NOT_SUPPORTED} if the signal
 * level is unavailable with lower value indicating lower signal strength.
 */
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
private static int getSignalStrengthLevel(CellInfo cellInfo) {
    if (cellInfo instanceof CellInfoCdma) {
        return ((CellInfoCdma) cellInfo).getCellSignalStrength().getLevel();
    }
    if (cellInfo instanceof CellInfoGsm) {
        return ((CellInfoGsm) cellInfo).getCellSignalStrength().getLevel();
    }
    if (cellInfo instanceof CellInfoLte) {
        return ((CellInfoLte) cellInfo).getCellSignalStrength().getLevel();
    }
    if (cellInfo instanceof CellInfoWcdma) {
        return ((CellInfoWcdma) cellInfo).getCellSignalStrength().getLevel();
    }
    return CellularSignalStrengthError.ERROR_NOT_SUPPORTED;
}