contract balanceOf call, response "owner_address isn't set."

// init tronWeb
const TronWeb = require('tronweb')

const tronWeb = new TronWeb({
  fullNode: 'https://api.trongrid.io',
  solidityNode: 'https://api.trongrid.io',
})

// read trc20 account balance
let contract = await tronWeb.contract().at("TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t"); 
let result = await contract.balanceOf('TZ13rQk53DDvK2pR4nfBLyuYTR4EGAFBwT').call();

// response error
//(node:49919) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 14): class java.security.InvalidParameterException : owner_address isn't set

[joadr]

Why would you need to set an address for calling a balanceOf?

[keesdewit82]

Setting the private key is not a great advise to be honest. You should try to avoid keeping your private key available as a string in your application. Keep it on a secure device for example. Not in the memory of your software. Anyway, this issue can also be fixed by applying the following code:

tronWeb.setAddress('TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t');

So that would be:

const TronWeb = require('tronweb')

const tronWeb = new TronWeb({
  fullNode: 'https://api.trongrid.io',
  solidityNode: 'https://api.trongrid.io',
})

// set the owner address
tronWeb.setAddress('TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t');

// read trc20 account balance
let contract = await tronWeb.contract().at("TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t"); 
let result = await contract.balanceOf('TZ13rQk53DDvK2pR4nfBLyuYTR4EGAFBwT').call();```