Interact with Contract

Initialize web3 instance

Trước tiên bạn cần khởi tạo web3

let web3 = Web3.InfuraRinkebyWeb3()
let data = wallet.data
let keystoreManager: KeystoreManager
if wallet.isHD {
    let keystore = BIP32Keystore(data)!
    keystoreManager = KeystoreManager([keystore])
} else {
    let keystore = EthereumKeystoreV3(data)!
    keystoreManager = KeystoreManager([keystore])
}
web3.addKeystoreManager(keystoreManager)

Create Contract

Lưu ý: Khi tạo contract file contract phải có payable. Nếu không có thì tự thêm vào.

let contractABI = "..." // Contract ABI
let contractAddress = EthereumAddress(contractAddressString)!
let abiVersion = 2 // Contract ABI version
let contract = web3.contract(contractABI, at: contractAddress, abiVersion: abiVersion)!

Send Read Transaction

Chỉ định func, dùng contract để tạo transaction và tiến hành gửi.

let walletAddress = EthereumAddress(wallet.address)! // Your wallet address
let contractMethod = "SOMECONTRACTMETHOD" // Contract method you want to call
let parameters: [AnyObject] = [...]() // Parameters for contract method
var options = TransactionOptions.defaultOptions
options.from = walletAddress
options.gasPrice = .automatic
options.gasLimit = .automatic
let transaction = contract.method(contractMethod,parameters: parameters,transactionOptions: options)
let result = try! transaction.call()

Send Write Transaction

Chỉ định func, dùng contract tạo Transaction, thiết lập Gas Price, Gas Limit, truyền vào password tiến gửi transaction.

let value: String = "0.0" // Any amount of Ether you need to send
let walletAddress = EthereumAddress(wallet.address)! // Your wallet address
let contractMethod = "SOMECONTRACTMETHOD" // Contract method you want to write
let parameters: [AnyObject] = [...]() // Parameters for contract method
let amount = Web3.Utils.parseToBigUInt(value, units: .eth)
var options = TransactionOptions.defaultOptions
options.value = amount
options.from = walletAddress
options.gasPrice = .automatic
options.gasLimit = .automatic
let transaction = contract.write(contractMethod,parameters: parameters,extraData: extraData,transactionOptions: options)!
let result = try! transaction.send(password: "Your pass",transactionOptions: options)