contract EIP20Interface{
    //获取_owner地址的余额
    function balanceOf(address _owner) public view returns (uint256 balance);
    //转账:从自己账户向_to地址转入_value个Token
    function transfer(address _to, uint256 _value)public returns (bool success);

    //转账:从_from向_to转_value个Token
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success);
    //允许_spender从自己(调用方)账户转走_value个Token
    function approve(address _spender, uint256 _value) public returns (bool success);
    //自己_owner查询__spender地址可以转走自己多少个Token
    function allowance(address _owner, address _spender) public view returns (uint256 remaining);

    //转账的时候必须要调用的时间，比如Tranfer,TransferFrom
    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    //成功执行approve方法后调用的事件
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}
function balanceOf(address _owner) public view returns (uint256 balance);

//获取_owner地址的余额