web3 从合约调用的函数不起作用
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【中文标题】web3 从合约调用的函数不起作用【英文标题】：the function called from contract by web3 isn't working 【发布时间】：2021-10-17 10:15:45 【问题描述】：我正在做合同，想通过 web3 连接到 js 和 html。当我尝试在合约 save.sol 中执行功能 saveData 时，ganache 网络没有创建新块，但它应该这样做。
为什么 index.js 中的 contract.methods.saveData(date, resource, mycalculate, material) 不起作用？
web3的版本是1.5.1
代码如下所示
index.html:
<!DOCTYPE html>
ignored
<div style="text-align: center;">
<button type="submit" class="btn btn-primary" id="button_formCarbonEmission">Save</button>
<a href="./home.html" class="btn btn-primary">Back</a>
</div>
<script>
const form = document.querySelector('form')
const submitButton = document.querySelector('#button_formCarbonEmission')
submitButton.addEventListener('click', function onSubmitButtonClicked(event)
form.classList.add('was-validated')
)
form.addEventListener('submit', function onFormSubmit(event)
if(!form.checkValidity())
event.preventDefault()
event.stopPropagation()
)
</script>
</form>
</div>
</div>
<script src="../function/web3.min.js"></script>
<script src="../function/index.js"></script>
ignored
</body>
</html>
index.js：
// Initialize Web3
var web3 = new Web3('http://localhost:7545');
// Set Account
web3.eth.defaultAccount = '0x16E15b184F39c4fBE1A4B29052CE018c5748610B';
// Set Contract Abi
var ABI = [myabi];
// Set Contract Address
var contractAddress = 'myaddr'; // Add Your Contract address here!!!
// Set the Contract
var contract = new web3.eth.Contract(ABI, contractAddress);
// get the current time
var today = new Date();
var date = today.getFullYear()+'-' + (today.getMonth()+1) + '-' + today.getDate() + '-'
today.getHours() + ":" + today.getMinutes() + ":" + today.getSeconds;
//get the formCarbonEmission data
const submitBtn = document.getElementById("button_formCarbonEmission");
submitBtn.addEventListener('click', processFormData);
contract.methods.test().call().then(console.log);//work normally
function processFormData()
const form = document.forms['formCarbonEmission'];
const material = form.elements.material.value;
const resource = form.elements.resource.value;
const mycalculate = form.elements.mycalculate.value;
//save the data
contract.methods.saveData(date, resource, mycalculate, material).call(); **//this function isn't work**
//alert
alert("saved!");
保存.sol：
// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;
contract Storage
string b = "calculation a";
struct UserInfo
string time;
string source;
uint emission;
mapping (string => UserInfo) users;
function test() public view returns(string memory)
return b;
function saveData(string memory input_time, string memory input_source, string memory input_mycalculate, uint input_material) public
users[input_source].time = input_time;
if (keccak256(abi.encodePacked(input_mycalculate)) == keccak256(abi.encodePacked(b)))
users[input_source].emission = input_material * 3 / 2;//solidity isn't support integer
else
users[input_source].emission = input_material * 5 / 2;//solidity isn't support integer
/* function get() public view returns (string memory, uint, string memory)
return (source, emission, time);
*/
function search(string memory input_source) public view returns (uint, string memory)
return (users[input_source].emission, users[input_source].time);
【问题讨论】：
【参考方案1】：我通过创建文件“web3.js”并将文件注入到 index.js 中解决了这个问题
并添加了savedata的账号：
contract.methods.saveData(date, resource, mycalculate, material).send(
from:web3.eth.defaultAccount
)
【讨论】：
【参考方案2】：contract.methods.saveData(date, resource, mycalculate, material) 必须通过以下方式调用：
call(params) - 读取/模拟操作
send(params) - 写操作
如您所见，您的 call() 没有工作，因为您没有提供任何参数，但 send(params) 确实有效。
【讨论】：
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