Understanding Metamask: A Deeper Dive into Unity Plugin Integration

As a developer working with Unity and MetaMask, you are probably familiar with the popular decentralized finance (DeFi) platform’s mobile wallet. However, when integrating the MetaMask Unity Plugin, a common issue arises – the user is shown different Ethereum amounts than what the plugin requires.

Problem:

In our previous example, we integrated the MetaMask Unity plugin using the provided asset storage package and followed the documentation. The plugin is designed to show users the correct amount of Ether (ETH) for their wallet balance, as requested by the platform’s UI. However, in some cases, this value may not match what you have set in your project settings.

Solution:

To resolve this issue, let’s take a look at why the MetaMask Unity Plugin is showing different amounts than what you specified. The reason lies in the way the plugin interacts with the Ethereum blockchain and the wallet account balance.

When users interact with their Ethereum accounts, they are not directly interacting with your project’s wallet balance. Instead, it is an external API call that returns a certain amount of ETH for the user to transfer or withdraw from their balance. This is where things get interesting – the plugin uses this external API to retrieve the correct amount of ETH.

Unity Plugin Code:

To better understand how the code works, let’s take a closer look at the Metamask Unity plugin code. We will focus on the UnityPlugin class and its OnCoinChanged event handler:

using UnityEngine;
using MetaMask . Unity ;
public class UnityPlugin : MonoBehavior
{
// ... other variables and methods
private void OnCoinChanged ( Currency , ulong value ) ;
{
// Update the wallet balance UI with the correct amount of ETH
WalletBalanceUI . instance . SetWalletBalance ( coin . Name , value );
} }
} }

As you can see, the `OnCoinChanged event handler takes the current currency (e.g. Ether) and its corresponding value. It then updates a UI element called `WalletBalanceUI'' to display the correct amount of ETH.

Why are the amounts displayed differently:

The reason for this discrepancy lies in the way the MetaMask Unity Plugin interacts with the Ethereum blockchain. When a user adds or withdraws funds from their account, MetaMask sends an API request to retrieve the balance data. The plugin then updates the UI element using this API response.

In our case, when we update the “WalletBalanceUI” instance with the correct amount of ETH, we are actually updating the user’s wallet balance on the Ethereum blockchain. However, the plugin does not automatically send a wallet balance update request from the project side.

Workaround:

To resolve this issue, you need to ensure that when displaying your wallet balance on the MetaMask Unity Plugin, you use the correct amount of ETH as required by the platform. You can do this by:

• Using a trusted API to retrieve the user’s wallet balance.

• Passing the value retrieved from the project side (e.g. in “OnCoinChanged”) to the plugin.

Here is an example of an updated code snippet that demonstrates how to update the UI element with the correct amount of ETH:

“csharp

using UnityEngine;

using MetaMask . Unity ;

public class WalletBalanceUI : MonoBehavior

{

private void OnCoinChanged ( Coin , ulong value ) ;

{

// Update the wallet balance UI with the correct amount of ETH

WalletBalanceDisplay . Instance . SetWalletBalance ( coin . Name , value );

} }

} }

// Example usage in C

project code:

private WalletBalanceDisplay walletBalanceDisplay;

void Start()

{

walletBalanceDisplay = GetComponent();

walletBalanceDisplay.