bsc链 薄饼，用bnb添加/撤销都可以，用u的添加可以，撤销不行，交易也不能交易。提示 This transaction would fail

以下是代码， /* Submitted for verification at Etherscan.io on 2018-06-16 */

pragma solidity ^0.4.24; /**

• @title SafeMath
• @dev Math operations with safety checks that throw on error 防止整数溢出问题 / library SafeMath { function mul(uint256 a, uint256 b) internal pure returns (uint256) { uint256 c = a b; assert(a == 0 || c / a == b); return c; }

function div(uint256 a, uint256 b) internal pure returns (uint256) { // assert(b > 0); // Solidity automatically throws when dividing by 0 uint256 c = a / b; // assert(a == b * c + a % b); // There is no case in which this doesn't hold return c; }

function sub(uint256 a, uint256 b) internal pure returns (uint256) { assert(b <= a); return a - b; }

function add(uint256 a, uint256 b) internal pure returns (uint256) { uint256 c = a + b; assert(c >= a); return c; } }

contract StandardToken { //使用SafeMath using SafeMath for uint256;

//代币名称
string public name;
//代币缩写
string public symbol;
//代币小数位数(一个代币可以分为多少份)
uint8 public  decimals;
//代币总数
uint256 public totalSupply;

//交易的发起方(谁调用这个方法，谁就是交易的发起方)把_value数量的代币发送到_to账户
function transfer(address _to, uint256 _value) public returns (bool success);

//从_from账户里转出_value数量的代币到_to账户
function transferFrom(address _from, address _to, uint256 _value) public returns (bool success);

//交易的发起方把_value数量的代币的使用权交给_spender，然后_spender才能调用transferFrom方法把我账户里的钱转给另外一个人
function approve(address _spender, uint256 _value) public returns (bool success);

//查询_spender目前还有多少_owner账户代币的使用权
function allowance(address _owner, address _spender) public constant returns (uint256 remaining);

//转账成功的事件
event Transfer(address indexed _from, address indexed _to, uint256 _value);
//使用权委托成功的事件
event Approval(address indexed _owner, address indexed _spender, uint256 _value);

}

//设置代币控制合约的管理员 contract Owned {

// modifier(条件)，表示必须是权力所有者才能do something，类似administrator的意思
modifier onlyOwner() {
    require(msg.sender == owner);
    _;//do something 
}

//权力所有者
address public owner;

//合约创建的时候执行，执行合约的人是第一个owner
constructor() public {
    owner = msg.sender;
}
//新的owner,初始为空地址，类似null
address newOwner=0x0;

//更换owner成功的事件
event OwnerUpdate(address _prevOwner, address _newOwner);

//现任owner把所有权交给新的owner(需要新的owner调用acceptOwnership方法才会生效)
function changeOwner(address _newOwner) public onlyOwner {
    require(_newOwner != owner);
    newOwner = _newOwner;
}

//新的owner接受所有权,权力交替正式生效
function acceptOwnership() public{
    require(msg.sender == newOwner);
    emit OwnerUpdate(owner, newOwner);
    owner = newOwner;
    newOwner = 0x0;
}

}

//代币的控制合约 contract Controlled is Owned{

//创世vip
constructor() public {
   setExclude(msg.sender,true);
}

// 控制代币是否可以交易，true代表可以(exclude里的账户不受此限制，具体实现在下面的transferAllowed里)
bool public transferEnabled = true;

// 是否启用账户锁定功能，true代表启用
bool lockFlag=true;
// 锁定的账户集合，address账户，bool是否被锁，true:被锁定，当lockFlag=true时，恭喜，你转不了账了，哈哈
mapping(address => bool) locked;
// 拥有特权用户，不受transferEnabled和lockFlag的限制，vip啊，bool为true代表vip有效
mapping(address => bool) exclude;

//设置transferEnabled值
function enableTransfer(bool _enable) public onlyOwner returns (bool success){
    transferEnabled=_enable;
    return true;
}

//设置lockFlag值
function disableLock(bool _enable) public onlyOwner returns (bool success){
    lockFlag=_enable;
    return true;
}

// 把_addr加到锁定账户里，拉黑名单。。。
function addLock(address _addr) public onlyOwner returns (bool success){
    require(_addr!=msg.sender);
    locked[_addr]=true;
    return true;
}

//设置vip用户
function setExclude(address _addr,bool _enable) public onlyOwner returns (bool success){
    exclude[_addr]=_enable;
    return true;
}

//解锁_addr用户
function removeLock(address _addr) public onlyOwner returns (bool success){
    locked[_addr]=false;
    return true;
}
//控制合约 核心实现
modifier transferAllowed(address _addr) {
    if (!exclude[_addr]) {
        require(transferEnabled,"transfer is not enabeled now!");
        if(lockFlag){
            require(!locked[_addr],"you are locked!");
        }
    }
    _;
}

}

//端午节，代币离骚 contract LiSaoToken is StandardToken,Controlled {

//账户集合
mapping (address => uint256) public balanceOf;
mapping (address => mapping (address => uint256)) internal allowed;

constructor() public {
    totalSupply = 1000000000;//10亿
    name = "LiSao Token";
    symbol = "LS";
    decimals = 0;
    balanceOf[msg.sender] = totalSupply;
}

function transfer(address _to, uint256 _value) public transferAllowed(msg.sender) returns (bool success) {
    require(_to != address(0));
    require(_value <= balanceOf[msg.sender]);

    balanceOf[msg.sender] = balanceOf[msg.sender].sub(_value);
    balanceOf[_to] = balanceOf[_to].add(_value);
    emit Transfer(msg.sender, _to, _value);
    return true;
}

function transferFrom(address _from, address _to, uint256 _value) public transferAllowed(_from) returns (bool success) {
    require(_to != address(0));
    require(_value <= balanceOf[_from]);
    require(_value <= allowed[_from][msg.sender]);

    balanceOf[_from] = balanceOf[_from].sub(_value);
    balanceOf[_to] = balanceOf[_to].add(_value);
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
    emit Transfer(_from, _to, _value);
    return true;
}

function approve(address _spender, uint256 _value) public returns (bool success) {
    allowed[msg.sender][_spender] = _value;
    emit Approval(msg.sender, _spender, _value);
    return true;
}

function allowance(address _owner, address _spender) public view returns (uint256 remaining) {
  return allowed[_owner][_spender];
}

}