Memo 傳輸擴展

Name: 使用Web3.js的Token2022
Availability: InStock

MemoTranfer 擴展是一個 Token 賬戶擴展，強制要求所有進入該代幣賬戶的轉賬都包含備忘錄，從而促進更高效的交易追蹤和用戶識別。

初始化代幣賬戶

要在 Token 賬戶上初始化 MemoTransfer 擴展，我們需要使用 enableRequiredMemoTransfers() 函數。

以下是如何創建帶有 Memo 傳輸擴展的代幣：

import { Keypair, SystemProgram, Transaction, sendAndConfirmTransaction } from "@solana/web3.js";
import {
  createInitializeAccountInstruction,
  createEnableRequiredMemoTransfersInstruction,
  getAccountLen,
  ExtensionType,
  TOKEN_2022_PROGRAM_ID,
} from "@solana/spl-token";

const tokenAccount = Keypair.generate();

// Calculate the size needed for a Token account with Memo Transfer extension
const accountLen = getAccountLen([ExtensionType.MemoTransfer]);

// Calculate minimum lamports required for rent exemption
const lamports = await connection.getMinimumBalanceForRentExemption(accountLen);

// Create the account with the correct size and owner
const createAccountInstruction = SystemProgram.createAccount({
  fromPubkey: keypair.publicKey,
  newAccountPubkey: tokenAccount.publicKey,
  space: accountLen,
  lamports,
  programId: TOKEN_2022_PROGRAM_ID,
});

// Initialize the Memo Transfer extension
const enableMemoTransferInstruction = createEnableRequiredMemoTransfersInstruction(
  destinationTokenAccount.publicKey,
  destinationKeypair.publicKey,
  undefined,
  TOKEN_2022_PROGRAM_ID,
);

// Initialize the Token account itself
const initializeAccountInstruction = createInitializeAccountInstruction(
  tokenAccount.publicKey,
  mint.publicKey,
  keypair.publicKey,
  TOKEN_2022_PROGRAM_ID,
);

const transaction = new Transaction().add(
  createAccountInstruction,
  initializeAccountInstruction,
  enableMemoTransferInstruction,
);

const signature = await sendAndConfirmTransaction(
  connection,
  transaction,
  [keypair, tokenAccount],
  { skipPreflight: false },
);

console.log(
  `Token accounts created! Check out your TX here: https://explorer.solana.com/tx/${signature}?cluster=devnet`,
);

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帶備忘錄的代幣轉賬

在 Solana 上使用 Memo 程式，我們有兩種可行的路徑。

構建我們自己的「原始」備忘錄指令，如下所示：

const message = "Hello, Solana";

new TransactionInstruction({
    keys: [{ pubkey: keypair.publicKey, isSigner: true, isWritable: true }],
    data: Buffer.from(message, "utf-8"), // Memo message. In this case it is "Hello, Solana"
    programId: new PublicKey("MemoSq4gqABAXKb96qnH8TysNcWxMyWCqXgDLGmfcHr"), // Memo program that validates keys and memo message
}),

或者我們可以下載 Memo 程式 SDK 後使用它，如下所示：

text

npm i @solana/spl-memo

在我們的例子中，我們將使用第二種選項，結果如下：

const memoInstruction = createMemoInstruction("Hello, world!", [keypair.publicKey]);

const transferInstruction = createTransferCheckedInstruction(
  tokenAccount,
  mint.publicKey,
  destinationTokenAccount.publicKey,
  keypair.publicKey,
  BigInt(100e6),
  6,
  undefined,
  TOKEN_2022_PROGRAM_ID,
);

const transferTransaction = new Transaction().add(memoInstruction, transferInstruction);

const transferSignature = await sendAndConfirmTransaction(connection, transferTransaction, [
  keypair,
]);

console.log(
  `Tokens transferred with memo! Check out your TX here: https://explorer.solana.com/tx/${transferSignature}?cluster=devnet`,
);

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禁用和啟用備忘錄

如果我們不想強制轉賬附帶備忘錄，可以使用 disableRequiredMemoTransfer 函數，操作如下：

const disableRequiredMemoTransfersInstruction = createDisableRequiredMemoTransfersInstruction(
  destinationTokenAccount,
  destinationKeypair.publicKey,
  undefined,
  TOKEN_2022_PROGRAM_ID,
);

const transferInstruction = createTransferCheckedInstruction(
  tokenAccount,
  mint.publicKey,
  destinationTokenAccount,
  keypair.publicKey,
  BigInt(100e6),
  6,
  undefined,
  TOKEN_2022_PROGRAM_ID,
);

const transaction = new Transaction().add(
  disableRequiredMemoTransfersInstruction,
  transferInstruction,
);

const signature = await sendAndConfirmTransaction(connection, transaction, [
  keypair,
  destinationKeypair,
]);

console.log(
  `Tokens transferred and account state changed! Check out your TX here: https://explorer.solana.com/tx/${signature}?cluster=devnet`,
);

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如果我們想重新啟用它，只需使用 enableRequiredMemoTransfers() 函數，如下所示：

const enableRequiredMemoTransfersInstruction = createEnableRequiredMemoTransfersInstruction(
  destinationTokenAccount,
  destinationKeypair.publicKey,
  undefined,
  TOKEN_2022_PROGRAM_ID,
);

const transferInstruction = createTransferCheckedInstruction(
  tokenAccount,
  mint.publicKey,
  destinationTokenAccount,
  keypair.publicKey,
  BigInt(100e6),
  6,
  undefined,
  TOKEN_2022_PROGRAM_ID,
);

const transaction = new Transaction().add(
  enableRequiredMemoTransfersInstruction,
  transferInstruction,
);

const signature = await sendAndConfirmTransaction(connection, transaction, [
  keypair,
  destinationKeypair,
]);

console.log(
  `Tokens transferred and account state changed! Check out your TX here: https://explorer.solana.com/tx/${signature}?cluster=devnet`,
);

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