Contract template

Time-limited crowdfunding

The crowdfunding token 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 same time as the contract is deployed.

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

Time-limited crowdfunding means that the start time and end time of crowdfunding are set

Contract Document: TimedCrowdsale.sol (opens new window)

test scripts: TimedCrowdsale.js (opens new window)

Deployment script: 14_deploy_TimedCrowdsale.js (opens new window)

Define the following variables when deploying the contract

Uint256 rate 			// how many ERC20 tokens are exchanged for 1ETH
Address payable wallet 	// to receive ETH beneficiary's address
IERC20 token			 // token address
Address tokenWallet		 // Tokens are sent from this address
Uint256 openingTime 		// Start time of crowdfunding
Uint256 closingTime 		// Crowd-funding end time

ERC20 method 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

// Return the token address
Token () Public view returns (IERC20)
// return the beneficiary's address
Wallet () Public View returns (Address payable)
// Return the exchange ratio
Rate () Public View returns (uint256)
// Return sales
WeiRaised () Public View returns (uint256)
// The token is purchased and sent to the specified address
BuyTokens (address beneficiary) public nonReentrant
// Special method
// Return 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
// Return to the crowdfunding end time
Public View returns (uint256)
// Returns whether the crowdfunding has started
IsOpen () Public View returns (bool)
// Returns whether the crowdfunding is over
hasClosed() public view returns (bool)