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Q-1: I,m new in Ethereum Bockchain,I have Created my new token that can be get by send from 0.01 to 1 ETH instant. When i did transaction in transaction hash Tokens Transferred From line showing 0x000000000.. If any need to addition in solidity code please suggest. Below is code and transaction hash.

Q-2: When anyone buy token instant to send 0.01 to 1 ETH than ETH going to my contract address and i don't know how i can send into creator address . Please help how i can send to my creator address.

Transaction Hash : https://etherscan.io/tx/0xe937a79a7b428ccb156011fde4e967ff0ad344aa91d22ac4bd58f9b4d6bb9da5

Solidity Code:

pragma solidity ^0.4.23;



/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 * Name : Techno Bit (TBIT)
 * Decimals : 8
 * TotalSupply : 10000000000
 * 
 * 
 * 
 * 
 */
library SafeMath {

    /**
    * @dev Multiplies two numbers, throws on overflow.
    */
    function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
        if (a == 0) {
            return 0;
        }
        c = a * b;
        assert(c / a == b);
        return c;
    }

    /**
    * @dev Integer division of two numbers, truncating the quotient.
    */
    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 a / b;
    }

    /**
    * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
    */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        assert(b <= a);
        return a - b;
    }

    /**
    * @dev Adds two numbers, throws on overflow.
    */
    function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
        c = a + b;
        assert(c >= a);
        return c;
    }
}

contract ForeignToken {
    function balanceOf(address _owner) constant public returns (uint256);
    function transfer(address _to, uint256 _value) public returns (bool);
}

contract ERC20Basic {
    uint256 public totalSupply;
    function balanceOf(address who) public constant returns (uint256);
    function transfer(address to, uint256 value) public returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
}

contract ERC20 is ERC20Basic {
    function allowance(address owner, address spender) public constant returns (uint256);
    function transferFrom(address from, address to, uint256 value) public returns (bool);
    function approve(address spender, uint256 value) public returns (bool);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

contract TechnoBit is ERC20 {

    using SafeMath for uint256;
    address owner = msg.sender;

    mapping (address => uint256) balances;
    mapping (address => mapping (address => uint256)) allowed;    

    string public constant name = "Techno Bit";
    string public constant symbol = "TBIT";
    uint public constant decimals = 8;

    uint256 public totalSupply = 10000000000e8;
    uint256 public totalDistributed =  1000000000e8;    
    uint256 public constant MIN_CONTRIBUTION = 1 ether / 100; // 0.01 Ether
    uint256 public tokensPerEth = 20000000e8;

    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);

    event Distr(address indexed to, uint256 amount);
    event DistrFinished();

    event Airdrop(address indexed _owner, uint _amount, uint _balance);

    event TokensPerEthUpdated(uint _tokensPerEth);

    event Burn(address indexed burner, uint256 value);

    bool public distributionFinished = false;

    modifier canDistr() {
        require(!distributionFinished);
        _;
    }

    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }


    function TechnoBit () public {
        owner = msg.sender;    
        distr(owner, totalDistributed);
    }

    function transferOwnership(address newOwner) onlyOwner public {
        if (newOwner != address(0)) {
            owner = newOwner;
        }
    }


    function finishDistribution() onlyOwner canDistr public returns (bool) {
        distributionFinished = true;
        emit DistrFinished();
        return true;
    }

    function distr(address _to, uint256 _amount) canDistr private returns (bool) {
        totalDistributed = totalDistributed.add(_amount);        
        balances[_to] = balances[_to].add(_amount);
        emit Distr(_to, _amount);
        emit Transfer(address(0), _to, _amount);

        return true;
    }

    function doAirdrop(address _participant, uint _amount) internal {

        require( _amount > 0 );      

        require( totalDistributed < totalSupply );

        balances[_participant] = balances[_participant].add(_amount);
        totalDistributed = totalDistributed.add(_amount);

        if (totalDistributed >= totalSupply) {
            distributionFinished = true;
        }

        // log
        emit Airdrop(_participant, _amount, balances[_participant]);
        emit Transfer(address(0), _participant, _amount);
    }

    function adminClaimAirdrop(address _participant, uint _amount) public onlyOwner {        
        doAirdrop(_participant, _amount);
    }

    function adminClaimAirdropMultiple(address[] _addresses, uint _amount) public onlyOwner {        
        for (uint i = 0; i < _addresses.length; i++) doAirdrop(_addresses[i], _amount);
    }

    function updateTokensPerEth(uint _tokensPerEth) public onlyOwner {        
        tokensPerEth = _tokensPerEth;
        emit TokensPerEthUpdated(_tokensPerEth);
    }

    function () external payable {
        getTokens();
     }

    function getTokens() payable canDistr  public {
        uint256 tokens = 0;

        // minimum contribution
        require( msg.value >= MIN_CONTRIBUTION );

        require( msg.value > 0 );

        // get baseline number of tokens
        tokens = tokensPerEth.mul(msg.value) / 1 ether;        
        address investor = msg.sender;

        if (tokens > 0) {
            distr(investor, tokens);
        }

        if (totalDistributed >= totalSupply) {
            distributionFinished = true;
        }
    }

    function balanceOf(address _owner) constant public returns (uint256) {
        return balances[_owner];
    }

    // mitigates the ERC20 short address attack
    modifier onlyPayloadSize(uint size) {
        assert(msg.data.length >= size + 4);
        _;
    }

    function transfer(address _to, uint256 _amount) onlyPayloadSize(2 * 32) public returns (bool success) {

        require(_to != address(0));
        require(_amount <= balances[msg.sender]);

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

    function transferFrom(address _from, address _to, uint256 _amount) onlyPayloadSize(3 * 32) public returns (bool success) {

        require(_to != address(0));
        require(_amount <= balances[_from]);
        require(_amount <= allowed[_from][msg.sender]);

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

    function approve(address _spender, uint256 _value) public returns (bool success) {
        // mitigates the ERC20 spend/approval race condition
        if (_value != 0 && allowed[msg.sender][_spender] != 0) { return false; }
        allowed[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        return true;
    }

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

    function getTokenBalance(address tokenAddress, address who) constant public returns (uint){
        ForeignToken t = ForeignToken(tokenAddress);
        uint bal = t.balanceOf(who);
        return bal;
    }

    function withdraw() onlyOwner public {
        address myAddress = this;
        uint256 etherBalance = myAddress.balance;
        owner.transfer(etherBalance);
    }

    function burn(uint256 _value) onlyOwner public {
        require(_value <= balances[msg.sender]);
        // no need to require value <= totalSupply, since that would imply the
        // sender's balance is greater than the totalSupply, which *should* be an assertion failure

        address burner = msg.sender;
        balances[burner] = balances[burner].sub(_value);
        totalSupply = totalSupply.sub(_value);
        totalDistributed = totalDistributed.sub(_value);
        emit Burn(burner, _value);
    }

    function withdrawForeignTokens(address _tokenContract) onlyOwner public returns (bool) {
        ForeignToken token = ForeignToken(_tokenContract);
        uint256 amount = token.balanceOf(address(this));
        return token.transfer(owner, amount);
    }
}

enter image description here

1

You need to call the withdraw() function to transfer the ETH sent to the contract to the owner account.

function withdraw() onlyOwner public {
    address myAddress = this;
    uint256 etherBalance = myAddress.balance;
    owner.transfer(etherBalance);
}
  • already added this function but how to withdraw from myetherwallet using contact function ? – zulfiqar ali Sep 28 '18 at 15:46
0

Ans 1 : You are supplying total supply of token must belong to some address like Owner and when we transfer that token it will emit transfer event witch specify sender,receiver,amount but in you case sender = address(0) == 0x0000000000000000000000000000000000000000. That's why this is showing you that address. For correction update distr function.

function distr(address _to, uint256 _amount) canDistr private returns (bool) {
    // Check owner has amount to transfer.
    require(balances[owner] >= _amount);
    totalDistributed = totalDistributed.add(_amount);        
    balances[_to] = balances[_to].add(_amount);
    // Owner transfer amount and reduce token balance
    balances[owner] = balances[owner].sub(_amount);
    emit Distr(_to, _amount);
    // emit Transfer function (sender == owner)
    emit Transfer(owner, _to, _amount);

    return true;
}

Ans 2 : You need to add owner.transfer(msg.value); in getToken() function.

function getTokens() payable canDistr  public {
    uint256 tokens = 0;

    // minimum contribution
    require( msg.value >= MIN_CONTRIBUTION );

    require( msg.value > 0 );

    // get baseline number of tokens
    tokens = tokensPerEth.mul(msg.value) / 1 ether;        
    address investor = msg.sender;

    if (tokens > 0) {
        // if token transfer to caller account, ether will be transfer to 
        // contract owner's account.
        require(distr(investor, tokens));
        owner.transfer(msg.value);
    }

    if (totalDistributed >= totalSupply) {
        distributionFinished = true;
    }
}
  • Yous so nice thanks .. i was use your rcommend code but now ETH going to owner wallet but buyer not getting tokens . can you tell me with same code that i was posted and also already withdraw function added . can you tell me how to withdraw from contract to owner wallet in myetherwallet contract>withdraw function ? – zulfiqar ali Sep 28 '18 at 21:18

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