Tag for the questions related to the deployment of the contracts using Ethereum wallet.
1
vote
0answers
18 views
How can I implement ethereum If I'm making an exchange service like cex.io [on hold]
I was wondering how cex.io manages ethereum service on their website.
I know what happens with bitcoin. They have 1 wallet and daemon on their server for each coin. for example bitcoin. Then When I ...
0
votes
1answer
15 views
How to create withdraw token requests on my custom token sale dashboard
I created a token sale dashboard. Users can send BTC,LTC,ETH to dashboard. When user send BTC, LTC or ETH to dashboard, they get tokens to their dashboard budget (offchain) based on current token ...
1
vote
2answers
19 views
How to get all index value?
contract Bar{
struct Foo{
uint x;
}
mapping(uint => Foo[]) foo;
function add(uint id, uint _x) public {
foo[id].push(Foo(_x));
}
function get(uint id, ...
1
vote
0answers
16 views
How to interconversion between privatekey and keystore with password in interactive console
When I execute geth attach attaching a active geth node into a interactive console .
I could use keystore and password to sendTransaction . But now I only know the raw privateKey，How to execute ...
0
votes
1answer
16 views
Ethereum unlock account
Is there any way to unlock the ethereum account when using the infura api.
Can only metamask do it?
I would not like to use metamask because not every user has it on the browser
1
vote
0answers
11 views
creation of Hourglass errored: transaction execution failed
I don't know why I'm getting this error while deploying 2 of my contracts.
creation of Hourglass errored: transaction execution failed
while code compiles successfully no issues there.
...
0
votes
2answers
20 views
How does the User sign Ethereum transactions when interacting with blockchain via an web3j-based intermediate API?
We have a private Ethereum network running in our testbed. And a web3j-based (Java) API exposes various functionalities to the deployed smart contracts on the blockchain. The API connects to the ...
0
votes
2answers
32 views
ETC Stuck in ETH standard wallet contract
I used to use the standard wallet contract in Mist to store ETH and as a result have some ETC still stored in the wallet contract address according to the ETC block explorer. I am trying to figure out ...
0
votes
1answer
29 views
Need help with smart contract
My code on Solidity is:
contract Recoverable is Ownable {
/// @dev Empty constructor (for now)
function Recoverable() public {
}
/// @dev This will be invoked by the owner, when owner wants ...
1
vote
0answers
18 views
trading a secret message with some person only after money is paid
I want to build a DAPP where person A trades a message with person B for ether. Since the message is secret, person A encrypts the message by using public key of person B and stores the message in ...
0
votes
1answer
29 views
Metamask stuck at Unknown network ID
I'm getting unknown network ID error on transferring a token in meta mask as in the image below. I'm using local network with ganache. I can transfer from metamask account to another after ...
0
votes
0answers
22 views
How does online wallets handle ERC20 tokens behind the scenes? [duplicate]
Described in the title: How do online wallets handle ERC20 tokens behind the scenes?
Or centralised exchanges in that matter. Are they simply communicating with the ethereum blockchain to generate ...
2
votes
0answers
16 views
“data” field is not working in Ethereum QR Code mobile payment
Recently, I am working on generating an Ethereum QR code that mobile wallet (e.g. imToken) can scan and pay from there.
But the problem is that I cannot pass the data value.
I use C# code to generate ...
0
votes
1answer
21 views
Can security tokens (ST-20) and utility tokens (ERC-20) exists on same blockchain?
I am trying to build a dApp in which the functionalities of the dApp can be accessed by utility token but in the same app I wish to tokenize the securities as well. Can my utility tokens and the ...
0
votes
2answers
14 views
How to extract value from hashed output
I am trying to make updates to a standard voting dapp. My aim is to list out voter who has voted for a candidate.
So far I have implemented the following:
voting.sol:
struct voter {
bytes32 ...
0
votes
1answer
16 views
Metamask won't display correct balance after creating customrpc for ganache accounts
I made a customrpc network on metamask using the correct server and imported a private key from ganache, which worked but the eth balance is displaying 0 when I expected it to display 100.
According ...
0
votes
1answer
24 views
miner.start() cannot deploy my contract
My environment:
geth 1.8.11
Ethereum Wallet
Mist Browser
windows 10
I try to deploy a new contract in the Ethereum Wallet.
I execute (miner.start();) in the Geth JavaScript console to get some ...
0
votes
1answer
50 views
web3 and web3 provider engine
Scenario:
Import json file and decrypt it
Use account to sign the messsage
I can do this with web3(Web3.providers.HttpProvider) or with web3-provider-engine. What is major difference between using ...
0
votes
1answer
21 views
The Token sale contract is returning an exception everytime. Tested on ropsten and there it is working fine
The below is the code for The token:
pragma solidity ^0.4.16;
interface tokenRecipient { function receiveApproval(address _from, uint256
_value, address _token, bytes _extraData) external; }...
0
votes
2answers
59 views
Using Ethereum public and private keys to encrypt and decrypt message (metamask client)
I am trying to use Ethereum private and public keys for message encryption like PGP and I found out this npm module on github, https://github.com/pubkey/eth-crypto#encryptwithpublickey, which it lets ...
0
votes
1answer
60 views
How can we assign unique hash id to the id that created inside our smart contract in ethereum?
I am using truffle, ganache and web3. I am initializing user id in smart contract while deploying the smart contract. As of now, everything is done by account[0] of Ganache.
Now, I want functionality ...
1
vote
1answer
26 views
NodeJS with HDWalletProvider
I want to execute signed Ethereum transactions from a NodeJS program. I am creating a web3_provider like this
var contract = require("truffle-contract");
var provider = new HDWalletProvider("nemonic"...
0
votes
0answers
14 views
IPFS in android using java
need pro help over here. I have an android project that use IPFS (InterPlanetary File System) to transfer few files and get the keys to store. I been searched in various online pages and read lots of ...
0
votes
1answer
26 views
Do you know any good code sample of Web3j with Android? [closed]
Do you have any good code sample of Web3j with Android?
There is an example in the official docs, but I don't think it is not well self explanatory.
I'd like to see an example of wallet generating or ...
0
votes
1answer
30 views
What are offchain and onchain Transactions?
What is meant by off-chain and on-chain transactions? I don't get the meaning of off-chain and on-chain in general.
0
votes
1answer
253 views
Error in Ethereum Wallet:“Couldn't estimate gas, resorting to default parameters. Transaction is likely cheaper than the estimate”
I am using ethereum wallet for deploying contracts in my private blockchain. But whenever I try to send a transaction in my ethereum wallet it shows an error that says, "Couldn't estimate gas, ...
1
vote
1answer
524 views
Getting this message in mist: Couldn't estimate gas, resorting to default parameters. Transaction is likely cheaper than the estimate
What is this error message in red:
Couldn't estimate gas, resorting to default parameters.
Transaction is likely cheaper than the estimate
I have written a smart contract:
pragma solidity ^0.4....
0
votes
0answers
19 views
transaction is sending and not executing in mist wallet
i have written this smart contract
pragma solidity ^0.4.0;
contract MyFirstContract {
uint256 counter =0;
function increase() public {
counter++;
}
function decrease() ...
2
votes
1answer
35 views
Can't use constructor() when deploying a contract from ethereum wallet
Take the following code:
pragma solidity 0.4.24;
contract TestCoin {
mapping(address => uint256) public balanceOf;
uint256 public totalSupply;
constructor(uint256 initialSupply) ...
0
votes
1answer
37 views
Access DApps publicly
I have created my own private blockchain network in LAN.I am using admin.peer() function for adding a new peer to network,for this admin.peer function to work I need an IP address.So my question is ...
0
votes
0answers
27 views
Can't deploy token to private network
I tried to implement a token from this page
But when he tries to send it from the account, throws a error.
Contract code:
pragma solidity ^0.4.24;
library SafeMath {
function add(uint a, uint ...
0
votes
1answer
25 views
Do we have to compile and deploy our contract to ethereum each time we start a test rpc?
I'm trying to develop a voting application, I have successfully compiled the app and also deployed it to ethereum blockchain. Now I've closed the test rpc and node console, and when I restarted node ...
0
votes
1answer
13 views
How to handle exceptions in ethreum private network using revert(),throw
I am running a private ethereum network using
geth --rpc --rpccorsdomain "*" --datadir ./chaindata --port "30330" --nodiscover --rpcapi "db,th,net,web3" --networkid 2010 init genesis.json
and ...
0
votes
0answers
17 views
Looping through and getting contract token balance?
To be able to query the balanceOf function of the many symbols, i've stored in database a reference of the contract address hash to it's symbol. I'm trying to get each token's balance passing in an ...
0
votes
1answer
58 views
Look for an address in a common.Address array in Golang
Im essentially looking for a way to use bytes.Compare() but on an array of ethereum addresses that are of type common.Address.. i need to search an array to see if another address exists in it and ...
0
votes
0answers
30 views
Wrapped ethereum showing in balance (ethplorer, etherchain) but is unavailable to trade
So I checked my balance on my MEW account 0x172342843d6Ec29DDD99AF0c3d3d734725c189C3 and it shows that I have 0.876 WETH balance. But I cannot neither trade it or unwrap in. Does any one have an idea ...
0
votes
0answers
18 views
How to get Ethereum Wallet to show all details of past transactions for an imported wallet contract?
In Ethereum Wallet (v0.10.0), I imported a wallet contract. For this contract, under “Latest Transactions”, there's a difference between transactions I did since importing it, and older transactions: ...
0
votes
1answer
18 views
Issues with transaction signing
I have a desktop app that accepts payment from user in ETH and provides it some service for a certain amount of time depending on the amount.
For that the user needs to sign the transaction in the ...
1
vote
1answer
36 views
There is any open source for mnemonic (recovery) phrase can be used in react project?
I want to know how to implement 12 words or 24 words mnemonic(recovery) phrase screen as "Create Wallet" part in the ethereum, ERC20 token wallet project built with React Native like as coinomi wallet....
1
vote
2answers
164 views
How execute a contract method with private key / sign send method?
I'd like to execute an erc20 contract method without unlocking a wallet, signing the transaction inside my code.
Here is how the code should look like:
public async send(sender: string, receiver: ...
0
votes
1answer
65 views
Airdrop function executing but balances not updating
I created the following code for token generation and airdrop. The token generation is working. I am able to execute the Drop() function (and got confirmations of contract execution) but the token ...
0
votes
1answer
9 views
ETH to Tokens Without Wallet
I wanted to buy tokens with ETH and send directly from my brocker to the token selling company, the transaction failed. is there a way to recover my ETH?
1
vote
0answers
13 views
Test cases required for Multisig wallet
Can you please suggest me some test use cases that are applicable for a smart contract that has a multi-signature wallet in Ethereum?
0
votes
0answers
12 views
How can I set the order that my contract functions appear in the Ethereum Wallet?
When I deploy a contract through the Ethereum Wallet and interact with it, the "READ FROM CONTRACT" shows its entries in a random order. Additionally, under "WRITE TO CONTRACT" in the "Select ...
1
vote
1answer
48 views
Transfer data using solidity transfer function
Can we use transfer function in solidity to transfer the data?
My code _dest.transfer(txn.value)(txn.data);
and it is showing the error that this type is not callable.
1
vote
1answer
94 views
Solidity compilation issue : Function overload clash during conversion to external types for arguments
I am new to solidity trying to compile the code which was an old example running good with old compiler. When I tried to compile the same in remix with latest compiler, I am getting the below issue. ...
0
votes
1answer
55 views
Use injected metamask inside of an ionic app
Ive seen this topic mentioned on the ethers of stack exchange before and mostly these questions go unanswered but being that ionic is basically a fancy webview i am wondering if anyone has manged to ...
0
votes
0answers
17 views
How to use bytes to get the same hashed output [duplicate]
I previously asked a question here:-link to previous question.
Found out the answer is to use string instead of bytes here:
pragma solidity ^0.4.18;
contract C {
bytes32 public temp;
...
0
votes
0answers
43 views
VM exception invalid opcode
pragma solidity ^0.4.24;
import './verification.sol';
contract Compute_winner is Verification {
address winner;
function bytes_to_int(bytes s) private pure returns (uint result) {
...
1
vote
1answer
51 views
Can we write pure native mobile app that on blockchain
I have a web-based blockchain application. On web, I can use metamask for making transaction. On mobile, I can use some Dapp browser such as Toshi ...
But I want to write a native application (pure ...
