Memo 傳輸擴展

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：

ts
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`);

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：

ts
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：

ts
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`);

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：

ts
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`);

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

ts
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`);

使用Web3.js的Token2022

Memo 傳輸擴展

初始化代幣賬戶

帶備忘錄的代幣轉賬

禁用和啟用備忘錄