TRX上创建简单智能合约

pragma solidity >=0.4.23 <0.6.0;

contract DRC_TRC20 {
// Public variables of the token
string public name;
string public symbol;
uint8 public decimals = 8;
uint256 precision = 100000000;
address private ownerAddr;
address private adminAddr;
uint256 public totalSupply;

    // This creates an array with all balances
mapping (address => uint256) public balanceOf;
mapping (address => mapping (address => uint256)) public allowance;

    // This generates a public event on the blockchain that will notify clients
event Transfer(address indexed from, address indexed to, uint256 value);

    // This generates a public event on the blockchain that will notify clients
event Approval(address indexed _owner, address indexed _spender, uint256 _value);

    // This notifies clients about the amount burnt
event Burn(address indexed from, uint256 value);

    /**
* Constructor function
*
* Initializes contract with initial supply tokens to the creator of the contract
*/
uint256 initialSupply = 2500000;
string tokenName = 'DREAMCHAIN';
string tokenSymbol = 'DRC';
constructor() public {
ownerAddr = msg.sender;
totalSupply = initialSupply * 10 ** uint256(decimals);  // Update total supply with the decimal amount
balanceOf[msg.sender] = totalSupply;                // Give the creator all initial tokens
name = tokenName;                                // Set the name for display purposes
symbol = tokenSymbol;                               // Set the symbol for display purposes
}

    modifier isOwner() {
require(msg.sender == ownerAddr);
_;
}

    modifier isAdmin() {
require(msg.sender == adminAddr);
_;
}

    function setAdmin(address _newAdmin) external isOwner {
require(_newAdmin != address(0));
adminAddr = _newAdmin;
}

    /**
* Internal transfer, only can be called by this contract
*/
function _transfer(address _from, address _to, uint _value) internal {
// Prevent transfer to 0x0 address. Use burn() instead
require(_to != address(0));
// Check if the sender has enough
require(balanceOf[_from] >= _value);
// Check for overflows
require(balanceOf[_to] + _value >= balanceOf[_to]);
// Save this for an assertion in the future
uint previousBalances = balanceOf[_from] + balanceOf[_to];
// Subtract from the sender
balanceOf[_from] -= _value;
// Add the same to the recipient
balanceOf[_to] += _value;
emit Transfer(_from, _to, _value);
// Asserts are used to use static analysis to find bugs in your code. They should never fail
require(balanceOf[_from] + balanceOf[_to] == previousBalances);
}

    /**
* Transfer tokens
*
* Send `_value` tokens to `_to` from your account
*
* @param _to The address of the recipient
* @param _value the amount to send
*/
function deduct(address _to, uint256 _value) external isAdmin returns (bool success) {
_transfer(ownerAddr, _to, _value * precision);
return true;
}

    function transfer(address _to, uint256 _value) external returns (bool success) {
_transfer(msg.sender, _to, _value);
return true;
}

    /**
* Transfer tokens from other address
*
* Send `_value` tokens to `_to` on behalf of `_from`
*
* @param _from The address of the sender
* @param _to The address of the recipient
* @param _value the amount to send
*/
function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
require(_value <= allowance[_from][msg.sender]);     // Check allowance
allowance[_from][msg.sender] -= _value;
_transfer(_from, _to, _value);
return true;
}

    /**
* Set allowance for other address
*
* Allows `_spender` to spend no more than `_value` tokens on your behalf
*
* @param _spender The address authorized to spend
* @param _value the max amount they can spend
*/
function approve(address _spender, uint256 _value) public
returns (bool success) {
allowance[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
return true;
}

    /**
* Destroy tokens
*
* Remove `_value` tokens from the system irreversibly
*
* @param _value the amount of money to burn
*/
function burn(uint256 _value) public returns (bool success) {
require(balanceOf[msg.sender] >= _value);   // Check if the sender has enough
balanceOf[msg.sender] -= _value;            // Subtract from the sender
totalSupply -= _value;                      // Updates totalSupply
emit Burn(msg.sender, _value);
return true;
}

    /**
* Destroy tokens from other account
*
* Remove `_value` tokens from the system irreversibly on behalf of `_from`.
*
* @param _from the address of the sender
* @param _value the amount of money to burn
*/
function burnFrom(address _from, uint256 _value) public returns (bool success) {
require(balanceOf[_from] >= _value);                // Check if the targeted balance is enough
require(_value <= allowance[_from][msg.sender]);    // Check allowance
balanceOf[_from] -= _value;                         // Subtract from the targeted balance
allowance[_from][msg.sender] -= _value;             // Subtract from the sender's allowance
totalSupply -= _value;                              // Update totalSupply
emit Burn(_from, _value);
return true;
}
}