android开发中如何判断手机中存在的sim卡数量？

1.Android M及以上版本：

TelephonyManager manager = (TelephonyManager)
                getSystemService(Context.TELEPHONY_SERVICE);
     
        if(Build.VERSION.SDK_INT >=Build.VERSION_CODES.M) {
            int numSlots = manager.getPhoneCount();
                 
        }

TelophonyManager源码中getPhoneCount（）函数如下：

/**
     * Returns the number of phones available.
     * Returns 1 for Single standby mode (Single SIM functionality)
     * Returns 2 for Dual standby mode.(Dual SIM functionality)
     */
    public int getPhoneCount() {
        int phoneCount = 1;
        switch (getMultiSimConfiguration()) {
            case UNKNOWN:
                phoneCount = 1;
                break;
            case DSDS:
            case DSDA:
                phoneCount = PhoneConstants.MAX_PHONE_COUNT_DUAL_SIM;
                break;
            case TSTS:
                phoneCount = PhoneConstants.MAX_PHONE_COUNT_TRI_SIM;
                break;
        }
        return phoneCount;
    }

/**
     * Returns the multi SIM variant
     * Returns DSDS for Dual SIM Dual Standby
     * Returns DSDA for Dual SIM Dual Active
     * Returns TSTS for Triple SIM Triple Standby
     * Returns UNKNOWN for others
     */
    /** {@hide} */
    public MultiSimVariants getMultiSimConfiguration() {
        String mSimConfig =
            SystemProperties.get(TelephonyProperties.PROPERTY_MULTI_SIM_CONFIG);
        if (mSimConfig.equals("dsds")) {
            return MultiSimVariants.DSDS;
        } else if (mSimConfig.equals("dsda")) {
            return MultiSimVariants.DSDA;
        } else if (mSimConfig.equals("tsts")) {
            return MultiSimVariants.TSTS;
        } else {
            return MultiSimVariants.UNKNOWN;
        }
    }

dsds (双卡单通)

dsda (双卡双通)

tsts (三卡单通)