ethereum

问题 I'm trying to make an Ethereum mining client using C#, and I need to check whether the system has AMD or NVIDIA. This is because the program needs to know whether it should mine Ethereum via CUDA or OpenCL. 回答1: You need to use System.Management Namespace (You can find under references/Assemblies) After adding namespace you need to navigate all properties of ManagementObject and navigate all properties of propertydata till founding description on name property. I wrote this solution for

问题 I would like to install web3 into my mobile App project. However I am having issues with accessing it without having a buch of red screens saying I can't access these files within it. I tried to manually update the paths etc; What I've done is in my App folder: npm install web3 Then I see the node_modules folder in my App directory... however, I am not able to require the module in my index.js file with a simple: var Web3 = require('web3'); // throws error var web3 = new Web3(); function

问题 I am developing smart contracts for some use-cases and currently I'm working on optimization of smart contracts. I am confused with something that I found interesting on Hitchiker's Guide. In the section 4- Iterating the contract code // returns true if proof is stored // *read-only function* function hasProof(bytes32 proof) constant returns (bool) { for (uint256 i = 0; i < proofs.length; i++) { if (proofs[i] == proof) { return true; } } return false; } For this code above, He states that

问题 Parity doesn't seem to have any documentation on what it's console output means. At least none that I've found which admittedly doesn't mean a whole lot. Can anyone give me a breakdown of the meaning of the following line? 2018-03-09 00:05:12 UTC Syncing #4896969 61ee…bdad 2 blk/s 508 tx/s 16 Mgas/s 645+ 1 Qed #4897616 17/25 peers 4 MiB chain 135 MiB db 42 MiB queue 5 MiB sync RPC: 0 conn, 0 req/s, 182 µs Thanks. 回答1: Why document when you can just read code? (bleh) 2018-03-09 00:05:12 UTC(1)

问题 Im trying to run my first HelloWorld smart contract on the Enthereum network. This is my HelloWorld.sol contract. pragma solidity ^0.5.0; contract HelloWorld { bytes32 message; constructor (bytes32 myMessage) public { message = myMessage; } function getMessage() public returns(bytes32) { return message; } } When I try to build this using solcjs HelloWorld.sol --bin , there is just one Warning and no errors. I have installed web3 and solc using npm. When I run this on a node var solc = require

问题 I'm trying to deploy a solidity program to my private ethereum network. However, when i call a method it's not working properly. This is what i'vd done before the call method. $ truffle console truffle(development)> var dApp undefined truffle(development)> Hello.deployed().then(function(instance) { dApp = instance; }) undefined truffle(development)> dApp.message.call() test env is below truffle@5.0.28 solc@0.5.10 linux centOS 7 geth@1.8.23 I tried all of the solution in answer about the below

问题 I am actually learning smart contract programming on ethereum and I work with truffle. Right now I am making this tutorial here: https://truffleframework.com/tutorials/building-dapps-for-quorum-private-enterprise-blockchains Where you learn how to create a dapp with quorum. But now I have a problem. I did everything exactly as described, but when I do: truffle migrate I get this error here: $ truffle migrate ⚠️ Important ⚠️ If you're using an HDWalletProvider, it must be Web3 1.0 enabled or

问题 I am a beginner in blockchian and I want to store a personal demographics data in a ethereum blockchain via solidity.I have some basic questions regarding that: Do I have to store the data in a smart contract ? Say I store multiple personal data in the blockchain , in that case would each personal data get stored in separate blocks using the same instance of the smart contract ? Are there any open source tools through which I can view the blocks in my local ethereum block chain? 回答1: I will

问题 I have looked at the other "out of gas" SO posts and they haven't solved my problem. I am using ganache-cli started with ganache-cli --account="0xce2ddf7d4509856c2b7256d002c004db6e34eeb19b37cee04f7b493d2b89306d, 2000000000000000000000000000000" I then execute truffle migrate --reset It returns with an error Error encountered, bailing. Network state unknown. Review successful transactions manually. Error: VM Exception while processing transaction: out of gas (Full error is at the end) These

问题 I installed truffle through npm with the following: sudo npm install -g truffle but when I run truffle list on the console it just gives me bash: truffle: command not found 回答1: Please make sure you have the latest version of npm and node installed. I had the same issue, I updated npm and node to latest version and it worked. npm install -g truffle works. 回答2: I had a similar problem. I ran npm i -g truffle and then when I tried to run truffle init I got an error: zsh: command not found: