Contract template

Finishable crowdfunding

Crowdfunding tokens means that after the token is issued, any address can purchase tokens from the crowdfunding address using ETH.

The exchange ratio between token and ETH is set at the time of contract deployment.

All crowdfunding contracts must be deployed after an ERC20 token has been successfully deployed. A fixed amount of ERC20 contracts has been set in the deployment script

Finalable crowdfunding is the method of ending crowdfunding that is added to the time-limited crowdfunding

Contract Document: FinalizableCrowdsale.sol (opens new window)

Test script: FinalizableCrowdsale.js (opens new window)

Deployment script: 16_deploy_FinalizableCrowdsale.js (opens new window)

extra

In the finalizablecrowdsale. sol contract file, you can set a method to end the crowdfunding. Because it is an internal function, it can only be set in the contract file.

function _finalization() internal {
    // Write the business logic after crowdfunding, which will be executed when finalize() method is called
    super._finalization();
}

Define the following variables when deploying the contract

uint256 rate               //Exchange ratio 1ETH how many ERC20 tokens to exchange
address payable wallet     //Address of the beneficiary receiving ETH
IERC20 token               //Tokens address
address tokenWallet        //The token is sent from this address
uint256 openingTime        // Start time of crowdfunding
uint256 closingTime        // Closing time of crowdfunding

The ERC20 approach needs to be implemented after the crowdfunding contract is placed

//Tokens in the sender's account must be approved for crowdfunding contracts after deployment
token.approve(crowdsale.address, SOME_TOKEN_AMOUNT);

Calling methods

//Returns the token address
token() public view returns (IERC20)          
//Return beneficiary's address              
wallet() public view returns (address payable)              
//Return conversion ratio
rate() public view returns (uint256) 
//Returned sales
weiRaised() public view returns (uint256)         
//The token is purchased and sent to the specified address       
buyTokens(address beneficiary) public nonReentrant payable  
//Special methods
//Returns the existing address of the token
tokenWallet() public view returns (address)                 
//Check the number of tokens left in the quota
remainingTokens() public view returns (uint256)
//Return to the crowdfunding start time
openingTime() public view returns (uint256)
//Return to the crowdfunding end time
closingTime() public view returns (uint256)
//Returns if the crowdfunding has started
isOpen() public view returns (bool)
//Returns whether the crowdfunding is over
hasClosed() public view returns (bool)
//Returns whether the contract has ended
finalized() public view returns (bool)
//Trigger the contract end method
finalize() public