Intergrating metamask in DAPP

Question

I am trying to integrate MetaMask version 5.3.1 in my Dapp. I am unable to call web3 functions like getBalance with the given instance, also I am unable to post a transaction.

Is there any documentation on that?

Error:

• ethereum.eth is undefined for calling web funcrtions like getBalance etc
• Transaction from address isn't valid for this account while sending a tx to metamask

The code I am using:

let metamaskTx = async () => {
    console.log("is metamask" , ethereum.isMetaMask) // true
    let accounts = await ethereum.enable()
    console.log(ethereum.selectedAddress) // prints selected address
    console.log(ethereum.networkVersion) // prints network ID
    // ethereum.eth is undefined
    let balance = await ethereum.eth.getBalance(ethereum.selectedAddress) 
    console.log(balance) 

    let transactionParameters = {
      to: '0xe58db6b23575a93c185f756618f8e42745d7292b',
      value: '0x1'
    }
    // fails with RPC Error: Error: Transaction from address isn't valid for this account
    ethereum.sendAsync({
      method: 'eth_sendTransaction',
      params: [transactionParameters],
      from: ethereum.selectedAddress,
    }, function(err, res){
      console.log({err})
      console.log({res})
    })
  }

Answer 1

I found the answer. I needed to user web3 passing ethereum injected by Metamask as provided. The code goes by:

 async sendTxWithMetamask() => {
  const ethereum = window.ethereum;
  let web3 = new Web3()
  let accounts = await ethereum.enable()
  web3.setProvider(ethereum);
  let selectedAddress = ethereum.selectedAddress 
  let balance = await web3.eth.getBalance(selectedAddress)
  console.log('Balance', balance)
  await web3.eth.sendTransaction({
    to: '0xe58db6b23575a93c185f756618f8e42745d7292b', value: web3.utils.toWei('1', 'ether'), from: selectedAddress
  })
};