sueboy: 30 12月 2018

[轉]Hashicorp Vault介绍和使用说明

https://blog.csdn.net/peterwanghao/article/details/83181932

get constract balance ethereum

https://ethereum.stackexchange.com/questions/21448/how-to-get-a-contracts-balance-in-solidity


    function contractbalance() public view returns (uint256){
        return address(this).balance;
    }


var thecontract = web3.eth.contract([{"constant":false,"inputs":[{"name":"x","type":"uint256"}],"name":"set","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"get","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"gett","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[],"name":"buy","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"anonymous":false,"inputs":[{"indexed":true,"name":"_from","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Set","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"tokens","type":"uint256"}],"name":"Buyvalue","type":"event"}]);
var MyContract = thecontract.at('0xbed0229199614a11e47c39d4800420de968627fa');

MyContract.buy({
  from:'0x5921a4C1B13afbD4b61d63e9c7BD47741C47B176', 
  value:web3.toWei("1", "ether")
}, console.log)

use remix ethereum online smart constract console Invalid JSON RPC response: undefined

Just try to click website function or action. Like compile, then try again console

web3.eth.accounts

maybe no error

Or

var web3 = new Web3(new Web3.providers.HttpProvider("http://myLocalHostIP:myRpcPort"));

ethereum smart contract payable

https://remix.ethereum.org/

Method 1： No function name


    function () payable external {
        t = msg.value;
        emit Buyvalue(msg.value);
    }

function () payable external {

OR

function () external payable {


pragma solidity >=0.4.0 <0.6.0;

contract SimpleStorage {
    uint storedData;
    uint256 t;
    event Set(address indexed _from, uint value);
    event Buyvalue(uint tokens);
    
    function set(uint x) public {
        storedData = x;
        emit Set(msg.sender, x);
    }

    function get() public view returns (uint) {
        return storedData;
    }
    
    function gett() public view returns (uint) {
        return t;
    }
    
    function () payable external {
        t = msg.value;
        emit Buyvalue(msg.value);
    }
}

MetaMask can not director send contract address eth, so use console


web3.eth.sendTransaction({
  to:'0xc356362efcce609fbe141b9bbda9e5ddc8a25526', 
  from:'0x5921a4C1B13afbD4b61d63e9c7BD47741C47B176', 
  value:web3.toWei("1", "ether")
}, console.log)

https://ethereum.stackexchange.com/questions/40862/how-to-set-msg-value-in-metamask

This method have warning about

Fallback function of contract SimpleStorage requires too much gas (21202). If the fallback function requires more than 2300 gas, the contract cannot receive Ether.

Method 2：buy function

https://www.ethereum.org/token


    function buy() payable public {
        t = msg.value;
        emit Buyvalue(msg.value);
    }

https://ethereum.stackexchange.com/questions/45398/call-a-payable-function-and-pay-ether-with-metamask


pragma solidity >=0.4.0 <0.6.0;

contract SimpleStorage {
    uint storedData;
    uint256 t;
    event Set(address indexed _from, uint value);
    event Buyvalue(uint tokens);
    
    function set(uint x) public {
        storedData = x;
        emit Set(msg.sender, x);
    }

    function get() public view returns (uint) {
        return storedData;
    }
    
    function gett() public view returns (uint) {
        return t;
    }
    
    function buy() payable public {
        t = msg.value;
        emit Buyvalue(msg.value);
    }
}

MetaMask can not director send contract address eth, so use console


var thecontract = web3.eth.contract([{"constant":false,"inputs":[{"name":"x","type":"uint256"}],"name":"set","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"get","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"gett","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[],"name":"buy","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"anonymous":false,"inputs":[{"indexed":true,"name":"_from","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Set","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"tokens","type":"uint256"}],"name":"Buyvalue","type":"event"}]);
var MyContract = thecontract.at('0x75e65c1f6de85183ba4937dafb62f54450f314b6');

MyContract.buy({
  from:'0x5921a4C1B13afbD4b61d63e9c7BD47741C47B176', 
  value:web3.toWei("1", "ether")
}, console.log)

Here have one problem about line 1： web3.eth.contract( ooxxooxx )

ooxxooxx How to get