我正在建立一个众筹智能合约并且我正在使用 ropsen tesnet 和 remix。
我这次众筹的代币地址是“0x6f734b9a097f17bc4c1f4348801587ce5e0177e2”
一切正常，我可以调用大部分函数。例如setStart，setEnd，hasEnded等。但是当我调用函数buyTokens时，我从remix中得到了这个错误：
交易到 FastInvestTokenCrowdsale.buyTokens 错误：所需的气体超过限制：300000。重要的气体估计也可能是合约代码出现问题的迹象。请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。
这是我众筹的编码：
/**
* Crowdsale for Fast Invest Tokens.
* Raised Ether will be stored safely at the wallet.
*
* Based on OpenZeppelin framework.
* https://openzeppelin.org
*
* Author: Paulius Tumosa
**/
pragma solidity ^0.4.18;
/**
* Safe Math library from OpenZeppelin framework
* https://openzeppelin.org
*
* @title SafeMath
* @dev Math operations with safety checks that throw on error
*/
library SafeMath {
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
uint256 c = a * b;
assert(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 token {
function transferFrom(address from, address to, uint256 value) public returns (bool);
}
/**
* @title FastInvestTokenCrowdsale
*
* Crowdsale have a start and end timestamps, where investors can make
* token purchases and the crowdsale will assign them tokens based
* on a token per ETH rate. Funds collected are forwarded to a wallet
* as they arrive.
*/
contract FastInvestTokenCrowdsale {
using SafeMath for uint256;
address public owner;
// The token being sold
token public tokenReward;
// Tokens will be transfered from this address
address internal tokenOwner;
// Address where funds are collected
address internal wallet;
// Start and end timestamps where investments are allowed
uint256 public startTime;
uint256 public endTime;
// Amount of tokens sold
uint256 public tokensSold = 0;
// Amount of raised money in wei
uint256 public weiRaised = 0;
// Funding goal and soft cap
uint256 constant public SOFT_CAP = 38850000000000000000000000;
uint256 constant public FUNDING_GOAL = 388500000000000000000000000;
// Tokens per ETH rates before and after the soft cap is reached
uint256 constant public RATE = 1000;
uint256 constant public RATE_SOFT = 1200;
// The balances in ETH of all investors
mapping (address => uint256) public balanceOf;
/**
* Event for token purchase logging
*
* @param purchaser who paid for the tokens
* @param beneficiary who got the tokens
* @param value weis paid for purchase
* @param amount amount of tokens purchased
*/
event TokenPurchase(address indexed purchaser, address indexed beneficiary, uint256 value, uint256 amount);
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(msg.sender == owner);
_;
}
function FastInvestTokenCrowdsale(address _tokenAddress, address _wallet, uint256 _start, uint256 _end) public {
require(_tokenAddress != address(0));
require(_wallet != address(0));
owner = msg.sender;
tokenOwner = msg.sender;
wallet = _wallet;
tokenReward = token(_tokenAddress);
require(_start < _end);
startTime = _start;
endTime = _end;
}
// Fallback function can be used to buy tokens
function () external payable {
buyTokens(msg.sender);
}
// Low level token purchase function
function buyTokens(address beneficiary) public payable {
require(beneficiary != 0x0);
require(validPurchase());
uint256 weiAmount = msg.value;
uint256 tokens = 0;
// Calculate token amount
if (tokensSold < SOFT_CAP) {
tokens = weiAmount.mul(RATE_SOFT);
if (tokensSold.add(tokens) > SOFT_CAP) {
uint256 softTokens = SOFT_CAP.sub(tokensSold);
uint256 amountLeft = weiAmount.sub(softTokens.div(RATE_SOFT));
tokens = softTokens.add(amountLeft.mul(RATE));
}
} else {
tokens = weiAmount.mul(RATE);
}
require(tokens > 0);
require(tokensSold.add(tokens) <= FUNDING_GOAL);
forwardFunds();
assert(tokenReward.transferFrom(tokenOwner, beneficiary, tokens));
balanceOf[beneficiary] = balanceOf[beneficiary].add(weiAmount);
// Update totals
weiRaised = weiRaised.add(weiAmount);
tokensSold = tokensSold.add(tokens);
TokenPurchase(msg.sender, beneficiary, weiAmount, tokens);
}
// Send ether to the fund collection wallet
function forwardFunds() internal {
wallet.transfer(msg.value);
}
// @return true if the transaction can buy tokens
function validPurchase() internal view returns (bool) {
bool withinPeriod = now >= startTime && now <= endTime;
bool nonZeroPurchase = msg.value != 0;
bool hasTokens = tokensSold < FUNDING_GOAL;
return withinPeriod && nonZeroPurchase && hasTokens;
}
function setStart(uint256 _start) public onlyOwner {
startTime = _start;
}
function setEnd(uint256 _end) public onlyOwner {
require(startTime < _end);
endTime = _end;
}
// @return true if crowdsale event has ended
function hasEnded() public view returns (bool) {
return now > endTime;
}
}
如果有人能指出我正确的方向，我将不胜感激。
无论我设置什么限制，我似乎总是“需要的气体超过限制”：
交易到 FastInvestTokenCrowdsale.buyTokens 错误：所需的气体超过限制：300000。重要的气体估计也可能是合约代码出现问题的迹象。请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。交易到 FastInvestTokenCrowdsale.buyTokens 待处理 ... 交易到 FastInvestTokenCrowdsale.buyTokens 错误：所需气体超过块气体限制：3000000000000。重要的气体估计也可能是合约代码中存在问题的迹象。请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。交易到 FastInvestTokenCrowdsale.buyTokens 待处理 ... 交易到 FastInvestTokenCrowdsale.buyTokens 错误：所需气体超过区块气体限制：3000000000000。重要的气体估计也可能是合约代码中存在问题的迹象。请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。交易到 FastInvestTokenCrowdsale.buyTokens 待处理 ... 交易到 FastInvestTokenCrowdsale.buyTokens 错误：所需的气体超过了块气体限制：3000000000000000000000000000000000。重要的气体估计也可能是合约代码中存在问题的迹象。请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。交易到 FastInvestTokenCrowdsale.buyTokens 待处理 ... 交易到 FastInvestTokenCrowdsale.buyTokens 错误：所需气体超过区块气体限制：300000000000000000000000000000000。重要的气体估计也可能是合约代码中存在问题的迹象。请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。transact to FastInvestTokenCrowdsale.buyTokens pending ... transact to FastInvestTokenCrowdsale.buyTokens errored: Gas required exceeds block gas limit: 30000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000. An important gas estimation might also be the sign of a problem in the contract code. 请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。交易到 FastInvestTokenCrowdsale.buyTokens 待定 ... 交易到 FastInvestTokenCrowdsale.buyTokens 错误：所需的气体超过了区块气体限制：3000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 的一个重要问题。请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。transact to FastInvestTokenCrowdsale.buyTokens pending ... transact to FastInvestTokenCrowdsale.buyTokens errored: Gas required exceeds block gas limit: 30000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000. An important gas estimation might also be the sign of a problem in the contract code. 请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。transact to FastInvestTokenCrowdsale.buyTokens pending ... transact to FastInvestTokenCrowdsale.buyTokens errored: Gas required exceeds block gas limit: 30000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000. An important gas estimation might also be the sign of a problem in the contract code. 请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。交易到 FastInvestTokenCrowdsale.buyTokens 待处理 ... 交易到 FastInvestTokenCrowdsale.buyTokens 错误：所需气体超过限制：10。一个重要的 gas 估计也可能是合约代码中存在问题的迹象。请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。交易到 FastInvestTokenCrowdsale.buyTokens 待处理 ... 交易到 FastInvestTokenCrowdsale.buyTokens 错误：所需气体超过限制：1. 重要的气体估计也可能是合约代码出现问题的迹象。请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。向 FastInvestTokenCrowdsale.buyTokens 交易错误：所需气体超过限制：1. 重要的气体估计也可能是合约代码出现问题的迹象。请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。向 FastInvestTokenCrowdsale.buyTokens 交易错误：所需气体超过限制：1. 重要的气体估计也可能是合约代码出现问题的迹象。请检查循环并确保您没有将值发送到非应付函数（这也是强气体估计的原因）。