React版Dapp开发模板（连接钱包、合约调用全流程和一个批量转账工具实战）

Verin
更新于 2022-08-12 19:12
阅读 5612

# 框架版本
框架分为两个版本:
1.[Nextjs版](https://github.com/Verin1005/NextJs-Dapp-Template)。几个大的Dapp(pancakeswap ,sushiswap,uniswap等等)用的都是这个技术栈，考虑到Dapp很多核心计算逻辑以及处理数据逻辑都在前端，建议使用这个Nextjs版本，在写业务的时候可以直接参考这三个大项目[Uniswap前端源码](https://github.com/Uniswap/interface)，[Sushiswap前端源码](https://github.com/sushiswap/sushiswap-interface)，[PancakeSwap前端源码](https://github.com/pancakeswap/pancake-frontendl)。
2.[Vite版本](https://github.com/Verin1005/React-Vite-Dapp-Template)。之前使用了CRA构建了一套，但是和很多Dapp开发的库不兼容，后来尝试了Vite，不仅速度快而且很多基本完美兼容，所以构建了一套基础逻辑和Nextjs一样为SPA页面服务的模板。

# 所使用的技术栈
两个框架技术栈主要是：TypeScript+React17+ethers+web3-react;

备注：这些技术栈也是根据其他项目使用情况来决定的，虽然有wagmi的web3 hooks库，可是由于没有其他项目使用，所以暂时未考虑，web3-react未使用beta版本也是基于这种考虑sushiswap已经使用了最新版本，后续再更新。整个模板参考了sushiswap和pancake以及网络上的部分教程。

# 项目源码导读
1.文件夹：
![image.png](https://img.learnblockchain.cn/attachments/2022/08/kfP9tRjS62f62b046ce89.png)
主要文件夹就是components，config，hooks和pages下的_app.tsx文件。

2.代码导读：

(1).全局配置(_app.tsx)：
```
import "styles/globals.css";
import type { AppProps } from "next/app";
import { Web3Provider } from "@ethersproject/providers";
import { Web3ReactProvider } from "@web3-react/core";
import Web3ReactManager from "components/Web3ReactManager/index";
import dynamic from "next/dynamic";

export function getLibrary(provider: any): Web3Provider {
  const library = new Web3Provider(provider);
  library.pollingInterval = 15000;
  return library;
}

const Web3ProviderNetwork = dynamic(() => import("../components/Web3ProviderNetwork/index"), { ssr: false });

function MyApp({ Component, pageProps }: AppProps) {
  return (
    <Web3ReactProvider getLibrary={getLibrary}>
      <Web3ProviderNetwork getLibrary={getLibrary}>
        <Web3ReactManager>
          <Component {...pageProps} />
        </Web3ReactManager>
      </Web3ProviderNetwork>
    </Web3ReactProvider>
  );
}

export default MyApp;
```

_app.tsx有关键的Web3ReactProvider，Web3ProviderNetwork和Web3ReactManager，后面所有的配置以及合约调用都会与他们有关，Web3ReactProvider是提供全局使用web3 hooks，Web3ProviderNetwork则是网络节点一系列的全局配置，Web3ReactManager则是用来操作钱包连接和钱包状态监听等；

(2).登陆钱包：
```
import React, { useState, useEffect } from "react";
import { useWeb3React } from "@web3-react/core";
import { network } from "config/constants/wallets";
import { NetworkContextName } from "config/index";

import useEagerConnect from "hooks/useEagerConnect";
import useInactiveListener from "hooks/useInactiveListener";

export default function Web3ReactManager({ children }: { children: JSX.Element }) {
  const { active } = useWeb3React();
  const { active: networkActive, error: networkError, activate: activateNetwork } = useWeb3React(NetworkContextName);

// try to eagerly connect to an injected provider, if it exists and has granted access already
  const triedEager = useEagerConnect();

// after eagerly trying injected, if the network connect ever isn't active or in an error state, activate itd
  useEffect(() => {
    if (triedEager && !networkActive && !networkError && !active) {
      activateNetwork(network);
    }
  }, [triedEager, networkActive, networkError, activateNetwork, active]);

// when there's no account connected, react to logins (broadly speaking) on the injected provider, if it exists
  useInactiveListener(!triedEager);

// handle delayed loader state
  const [showLoader, setShowLoader] = useState(false);
  useEffect(() => {
    const timeout = setTimeout(() => {
      setShowLoader(true);
    }, 600);

return () => {
      clearTimeout(timeout);
    };
  }, []);

// on page load, do nothing until we've tried to connect to the injected connector
  if (!triedEager) {
    return null;
  }

// if the account context isn't active, and there's an error on the network context, it's an irrecoverable error
  if (!active && networkError) {
    return <div>unknownError</div>;
  }

// if neither context is active, spin
  if (!active && !networkActive) {
    return showLoader ? <div>Loader</div> : null;
  }

return children;
}
```
在Web3ReactManager里面写好了连接钱包与管理状态的逻辑，核心是两个hooks：

**useEagerConnect**：

```import { useEffect, useState } from "react";
import { useWeb3React as useWeb3ReactCore } from "@web3-react/core";
import { injected } from "config/constants/wallets";
import { isMobile } from "web3modal";
import { connectorLocalStorageKey } from "config/connectors/index";
export function useEagerConnect() {
    const { activate, active } = useWeb3ReactCore(); // specifically using useWeb3ReactCore because of what this hook does
    const [tried, setTried] = useState(false);

useEffect(() => {
        injected.isAuthorized().then((isAuthorized) => {
            const hasSignedIn = window.localStorage.getItem(connectorLocalStorageKey);
            if (isAuthorized && hasSignedIn) {
                activate(injected, undefined, true)
                    // .then(() => window.ethereum.removeAllListeners(['networkChanged']))
                    .catch(() => {
                        setTried(true);
                    });
                // @ts-ignore TYPE NEEDS FIXING
                window.ethereum.removeAllListeners(["networkChanged"]);
            } else {
                if (isMobile() && window.ethereum && hasSignedIn) {
                    activate(injected, undefined, true)
                        // .then(() => window.ethereum.removeAllListeners(['networkChanged']))
                        .catch(() => {
                            setTried(true);
                        });
                    // @ts-ignore TYPE NEEDS FIXING
                    window.ethereum.removeAllListeners(["networkChanged"]);
                } else {
                    setTried(true);
                }
            }
        });
    }, [activate]);

useEffect(() => {
        if (active) {
            setTried(true);
        }
    }, [active]);

return tried;
}

export default useEagerConnect;
```
 连接主要是使用的useWeb3ReactCore里面的activate，这里存了localStorage主要作用是自动连接钱包与非自动，如果不需要自动则把hasSignedIn删除即可；
 
 **useInactiveListener**
 
```
import { useWeb3React as useWeb3ReactCore } from "@web3-react/core";
import { useEffect } from "react";

import { injected } from "config/constants/wallets";

/**
 * Use for network and injected - logs user in
 * and out after checking what network theyre on
 */
function useInactiveListener(suppress = false) {
  const { active, error, activate } = useWeb3ReactCore(); // specifically using useWeb3React because of what this hook does

useEffect(() => {
    const { ethereum } = window;

if (ethereum && ethereum.on && !active && !error && !suppress) {
      const handleChainChanged = () => {
        // eat errors
        activate(injected, undefined, true).catch((error) => {
          console.error("Failed to activate after chain changed", error);
        });
      };

ethereum.on("chainChanged", handleChainChanged);
      ethereum.on("accountsChanged", handleAccountsChanged);

return () => {
        if (ethereum.removeListener) {
          ethereum.removeListener("chainChanged", handleChainChanged);
          ethereum.removeListener("accountsChanged", handleAccountsChanged);
        }
      };
    }
    return undefined;
  }, [active, error, suppress, activate]);
}

export default useInactiveListener;
```
这里主要是监听钱包状态，比如账号更换和链更换；

备注：在config里面是配置钱包以及网络节点的，主要是NetworkConnector和wallets，一个是获取节点信息一个是配置钱包连接方式（metamask，walletconnect等等）

(2).合约调用
合约调用逻辑主要是在hooks文件夹下面的useContract：

```
import { useMemo } from "react";
import { useActiveWeb3React } from "hooks/useActiveWeb3React";
import { JsonRpcSigner, Web3Provider } from "@ethersproject/providers";
import { AddressZero } from "@ethersproject/constants";
import { isAddress } from "utils/isAddress";
import { getProviderOrSigner } from "utils";
import { Contract } from "@ethersproject/contracts";
export function useContract(address: string | undefined, ABI: any, withSignerIfPossible = true): Contract | null {
  const { library, account } = useActiveWeb3React();
  return useMemo(() => {
    if (!address || address === AddressZero || !ABI || !library) return null;
    try {
      return getContract(address, ABI, library, withSignerIfPossible && account ? account : undefined);
    } catch (error) {
      console.error("Failed to get contract", error);
      return null;
    }
  }, [address, ABI, library, withSignerIfPossible, account]);
}

export function getContract(address: string, ABI: any, library: Web3Provider, account?: string): Contract {
  if (!isAddress(address) || address === AddressZero) {
    throw Error(`Invalid 'address' parameter '${address}'.`);
  }
  return new Contract(address, ABI, getProviderOrSigner(library, account));
}
```
合约调用useContract是主方法，此方法已经自动兼容了连接钱包和未连接钱包状态，未连接钱包状态的时候会使用你默认的provider和节点（配置在wallets里面），连接钱包后则会使用你自身的钱包节点与provider。

使用如下：
 (1).实例一个合约：
```
export const useERC20 = (address: string, withSignerIfPossible = true) => {
    return useContract(address, ERC20_ABI, withSignerIfPossible);
};
```
(1).在组件中使用合约：

```
import { useERC20 } from "@/hooks/useContract";
export default function Index() {
const ERC20Instarnce = useERC20(address);

const handleTransfer=async()=>{
   const symbol = await ERC20Instarnce.symbol();
}
return...
}
```

自此从连接钱包到合约调用的逻辑全部讲完，其他业务逻辑就是正常的写Ts。

Vite版本与此类似，就不多说了。
基于Vite版本，我自己写了一个批量转账工具，包括合约在内都在我自己的git上开源，欢迎大家来star。

git地址[https://github.com/Verin1005](https://github.com/Verin1005)
批量转账网站[https://www.vtool.bio/#/](https://www.vtool.bio/#/)
Nextjs版模板[https://github.com/Verin1005/NextJs-Dapp-Template](https://github.com/Verin1005/NextJs-Dapp-Template)
Vite版模板[https://github.com/Verin1005/React-Vite-Dapp-Template](https://github.com/Verin1005/React-Vite-Dapp-Template)

**最后再备注一下**：两个框架都写过好几十次项目，一些其他模板遇到的Dapp开发问题都已经优化解决，比如连接钱包无法监听到网络切换，未连接钱包但是调用合约查询功能报错，以及连接钱包登录账户后依然使用了默认节点等等问题。不知道是否存在其他未知问题，欢迎大家来反馈。

框架版本

框架分为两个版本: 1.Nextjs版。几个大的Dapp(pancakeswap ,sushiswap,uniswap等等)用的都是这个技术栈，考虑到Dapp很多核心计算逻辑以及处理数据逻辑都在前端，建议使用这个Nextjs版本，在写业务的时候可以直接参考这三个大项目Uniswap前端源码，Sushiswap前端源码，PancakeSwap前端源码。 2.Vite版本。之前使用了CRA构建了一套，但是和很多Dapp开发的库不兼容，后来尝试了Vite，不仅速度快而且很多基本完美兼容，所以构建了一套基础逻辑和Nextjs一样为SPA页面服务的模板。

所使用的技术栈

两个框架技术栈主要是：TypeScript+React17+ethers+web3-react;

项目源码导读

1.文件夹：主要文件夹就是components，config，hooks和pages下的_app.tsx文件。

2.代码导读：

(1).全局配置(_app.tsx)：

import "styles/globals.css";
import type { AppProps } from "next/app";
import { Web3Provider } from "@ethersproject/providers";
import { Web3ReactProvider } from "@web3-react/core";
import Web3ReactManager from "components/Web3ReactManager/index";
import dynamic from "next/dynamic";

export function getLibrary(provider: any): Web3Provider {
  const library = new Web3Provider(provider);
  library.pollingInterval = 15000;
  return library;
}

const Web3ProviderNetwork = dynamic(() => import("../components/Web3ProviderNetwork/index"), { ssr: false });

function MyApp({ Component, pageProps }: AppProps) {
  return (
    &lt;Web3ReactProvider getLibrary={getLibrary}>
      &lt;Web3ProviderNetwork getLibrary={getLibrary}>
        &lt;Web3ReactManager>
          &lt;Component {...pageProps} />
        &lt;/Web3ReactManager>
      &lt;/Web3ProviderNetwork>
    &lt;/Web3ReactProvider>
  );
}

export default MyApp;

(2).登陆钱包：

import React, { useState, useEffect } from "react";
import { useWeb3React } from "@web3-react/core";
import { network } from "config/constants/wallets";
import { NetworkContextName } from "config/index";

import useEagerConnect from "hooks/useEagerConnect";
import useInactiveListener from "hooks/useInactiveListener";

export default function Web3ReactManager({ children }: { children: JSX.Element }) {
  const { active } = useWeb3React();
  const { active: networkActive, error: networkError, activate: activateNetwork } = useWeb3React(NetworkContextName);

  // try to eagerly connect to an injected provider, if it exists and has granted access already
  const triedEager = useEagerConnect();

  // after eagerly trying injected, if the network connect ever isn't active or in an error state, activate itd
  useEffect(() => {
    if (triedEager && !networkActive && !networkError && !active) {
      activateNetwork(network);
    }
  }, [triedEager, networkActive, networkError, activateNetwork, active]);

  // when there's no account connected, react to logins (broadly speaking) on the injected provider, if it exists
  useInactiveListener(!triedEager);

  // handle delayed loader state
  const [showLoader, setShowLoader] = useState(false);
  useEffect(() => {
    const timeout = setTimeout(() => {
      setShowLoader(true);
    }, 600);

    return () => {
      clearTimeout(timeout);
    };
  }, []);

  // on page load, do nothing until we've tried to connect to the injected connector
  if (!triedEager) {
    return null;
  }

  // if the account context isn't active, and there's an error on the network context, it's an irrecoverable error
  if (!active && networkError) {
    return &lt;div>unknownError&lt;/div>;
  }

  // if neither context is active, spin
  if (!active && !networkActive) {
    return showLoader ? &lt;div>Loader&lt;/div> : null;
  }

  return children;
}

在Web3ReactManager里面写好了连接钱包与管理状态的逻辑，核心是两个hooks：

useEagerConnect：

import { useWeb3React as useWeb3ReactCore } from "@web3-react/core";
import { injected } from "config/constants/wallets";
import { isMobile } from "web3modal";
import { connectorLocalStorageKey } from "config/connectors/index";
export function useEagerConnect() {
    const { activate, active } = useWeb3ReactCore(); // specifically using useWeb3ReactCore because of what this hook does
    const [tried, setTried] = useState(false);

    useEffect(() => {
        injected.isAuthorized().then((isAuthorized) => {
            const hasSignedIn = window.localStorage.getItem(connectorLocalStorageKey);
            if (isAuthorized && hasSignedIn) {
                activate(injected, undefined, true)
                    // .then(() => window.ethereum.removeAllListeners(['networkChanged']))
                    .catch(() => {
                        setTried(true);
                    });
                // @ts-ignore TYPE NEEDS FIXING
                window.ethereum.removeAllListeners(["networkChanged"]);
            } else {
                if (isMobile() && window.ethereum && hasSignedIn) {
                    activate(injected, undefined, true)
                        // .then(() => window.ethereum.removeAllListeners(['networkChanged']))
                        .catch(() => {
                            setTried(true);
                        });
                    // @ts-ignore TYPE NEEDS FIXING
                    window.ethereum.removeAllListeners(["networkChanged"]);
                } else {
                    setTried(true);
                }
            }
        });
    }, [activate]);

    useEffect(() => {
        if (active) {
            setTried(true);
        }
    }, [active]);

    return tried;
}

export default useEagerConnect;

连接主要是使用的useWeb3ReactCore里面的activate，这里存了localStorage主要作用是自动连接钱包与非自动，如果不需要自动则把hasSignedIn删除即可；

useInactiveListener

import { useWeb3React as useWeb3ReactCore } from "@web3-react/core";
import { useEffect } from "react";

import { injected } from "config/constants/wallets";

/**
 * Use for network and injected - logs user in
 * and out after checking what network theyre on
 */
function useInactiveListener(suppress = false) {
  const { active, error, activate } = useWeb3ReactCore(); // specifically using useWeb3React because of what this hook does

  useEffect(() => {
    const { ethereum } = window;

    if (ethereum && ethereum.on && !active && !error && !suppress) {
      const handleChainChanged = () => {
        // eat errors
        activate(injected, undefined, true).catch((error) => {
          console.error("Failed to activate after chain changed", error);
        });
      };

      const handleAccountsChanged = (accounts: string[]) => {
        if (accounts.length > 0) {
          // eat errors
          activate(injected, undefined, true).catch((error) => {
            console.error("Failed to activate after accounts changed", error);
          });
        }
      };

      ethereum.on("chainChanged", handleChainChanged);
      ethereum.on("accountsChanged", handleAccountsChanged);

      return () => {
        if (ethereum.removeListener) {
          ethereum.removeListener("chainChanged", handleChainChanged);
          ethereum.removeListener("accountsChanged", handleAccountsChanged);
        }
      };
    }
    return undefined;
  }, [active, error, suppress, activate]);
}

export default useInactiveListener;

这里主要是监听钱包状态，比如账号更换和链更换；

备注：在config里面是配置钱包以及网络节点的，主要是NetworkConnector和wallets，一个是获取节点信息一个是配置钱包连接方式（metamask，walletconnect等等）

(2).合约调用合约调用逻辑主要是在hooks文件夹下面的useContract：

import { useMemo } from "react";
import { useActiveWeb3React } from "hooks/useActiveWeb3React";
import { JsonRpcSigner, Web3Provider } from "@ethersproject/providers";
import { AddressZero } from "@ethersproject/constants";
import { isAddress } from "utils/isAddress";
import { getProviderOrSigner } from "utils";
import { Contract } from "@ethersproject/contracts";
export function useContract(address: string | undefined, ABI: any, withSignerIfPossible = true): Contract | null {
  const { library, account } = useActiveWeb3React();
  return useMemo(() => {
    if (!address || address === AddressZero || !ABI || !library) return null;
    try {
      return getContract(address, ABI, library, withSignerIfPossible && account ? account : undefined);
    } catch (error) {
      console.error("Failed to get contract", error);
      return null;
    }
  }, [address, ABI, library, withSignerIfPossible, account]);
}

export function getContract(address: string, ABI: any, library: Web3Provider, account?: string): Contract {
  if (!isAddress(address) || address === AddressZero) {
    throw Error(`Invalid 'address' parameter '${address}'.`);
  }
  return new Contract(address, ABI, getProviderOrSigner(library, account));
}

合约调用useContract是主方法，此方法已经自动兼容了连接钱包和未连接钱包状态，未连接钱包状态的时候会使用你默认的provider和节点（配置在wallets里面），连接钱包后则会使用你自身的钱包节点与provider。

使用如下： (1).实例一个合约：

export const useERC20 = (address: string, withSignerIfPossible = true) => {
    return useContract(address, ERC20_ABI, withSignerIfPossible);
};

(1).在组件中使用合约：

import { useERC20 } from "@/hooks/useContract";
export default function Index() {
const ERC20Instarnce = useERC20(address);

const handleTransfer=async()=>{
   const symbol = await ERC20Instarnce.symbol();
}
return...
}

自此从连接钱包到合约调用的逻辑全部讲完，其他业务逻辑就是正常的写Ts。

Vite版本与此类似，就不多说了。基于Vite版本，我自己写了一个批量转账工具，包括合约在内都在我自己的git上开源，欢迎大家来star。

git地址https://github.com/Verin1005 批量转账网站https://www.vtool.bio/#/ Nextjs版模板https://github.com/Verin1005/NextJs-Dapp-Template Vite版模板https://github.com/Verin1005/React-Vite-Dapp-Template

最后再备注一下：两个框架都写过好几十次项目，一些其他模板遇到的Dapp开发问题都已经优化解决，比如连接钱包无法监听到网络切换，未连接钱包但是调用合约查询功能报错，以及连接钱包登录账户后依然使用了默认节点等等问题。不知道是否存在其他未知问题，欢迎大家来反馈。

学分: 30
分类: Web3应用
标签: DAPP开发前端

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React版Dapp开发模板（连接钱包、合约调用全流程和一个批量转账工具实战）

框架版本

所使用的技术栈

项目源码导读

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