Substrate 区块链应用开发之存证模块的功能开发

寻月隐君
更新于 2024-04-05 14:57
阅读 959

Substrate区块链应用开发之存证模块的功能开发存证是一种在线服务，可用于在某一时间点验证计算机文件的存在性，最早是通过比特币网络带有时间戳的交易实现的。存证的应用场景有：数字版权司法存证供应链溯源电子发票...存证的作用是：证明文件在某一时间点确实存在证明文件在某一

# Substrate 区块链应用开发之存证模块的功能开发

存证是一种在线服务，可用于在某一时间点验证计算机文件的存在性，最早是通过比特币网络带有时间戳的交易实现的。 存证的应用场景有：

* 数字版权
* 司法存证
* 供应链溯源
* 电子发票
* ...

存证的作用是：

* 证明文件在某一时间点确实存在
* 证明文件在某一时间点确实没有被篡改
* 证明文件在某一时间点确实由某个人创建

## 实操

1. Open a terminal shell on your computer.
2. Clone the node template repository by running the following command:

```
git clone https://github.com/substrate-developer-hub/substrate-node-template
```

3. Change to the root of the node template directory by running the following command:

```
    cd substrate-node-template
```

4. Create a new branch to contain your work:

```
    git switch -c my-learning-branch-2024-04-05
```

5. Compile the node template by running the following command:

```
    cargo build --release
```

6. In the same terminal where you compiled your node, you can now start the node in development mode by running the following command:

```
    ./target/release/node-template --dev --tmp
```

![18111712290691_.pic.jpg](https://img.learnblockchain.cn/attachments/2024/04/Am1f4Lms660f9fa1de12a.jpg)
7. polkadot.js.org/apps 查看

![Snipaste_2024-04-05_12-16-12.png](https://img.learnblockchain.cn/attachments/2024/04/Y42XhoeL660f9fb3232d6.png)

8. 交易前查询状态 None

![chainstate_poemodule_0x01_2024-04-05_12-18-51.png](https://img.learnblockchain.cn/attachments/2024/04/lijXBnMq660f9fc789aa5.png)

9. 交易

![transaction01_2024-04-05_12-21-25.png](https://img.learnblockchain.cn/attachments/2024/04/oYUV7x62660f9fe4740b5.png)

10. 提交交易

![tx02_2024-04-05_12-22-49.png](https://img.learnblockchain.cn/attachments/2024/04/zA4e9NXc660fa000ebe67.png)

11. 交易后查询状态

![tx032024-04-05_12-25-36.png](https://img.learnblockchain.cn/attachments/2024/04/3xzPbOFj660fa01d522e8.png)

## 问题

1. 编译报错后使用的命令

```
    cargo clean
    cargo update
    cargo update -p wasm-bindgen
    cargo update -p librocksdb-sys
    cargo update -p schnorrkel@0.11.4
    cargo update -p anstream@0.6.13  -Z sparse-registry    
```

2. 编译报错：error\[E0220]: associated type `BlockNumber` not found for `T`

![blocknumber_err_2024-04-05_13-01-11.png](https://img.learnblockchain.cn/attachments/2024/04/hdWXr2e2660fa039284b9.png)

解决： 替换`T::BlockNumber`为`BlockNumberFor<T>`

* <https://substrate.stackexchange.com/questions/9848/associated-type-blocknumber-not-found-for-t>

## 参考

* <https://docs.substrate.io/tutorials/build-a-blockchain/build-local-blockchain/>
* <https://substrate.stackexchange.com/questions/9848/associated-type-blocknumber-not-found-for-t>
* <https://polkadot.js.org/apps>

## 更多详情

* <https://github.com/qiaopengjun5162/substrate-pallets-poe>

Substrate 区块链应用开发之存证模块的功能开发

存证是一种在线服务，可用于在某一时间点验证计算机文件的存在性，最早是通过比特币网络带有时间戳的交易实现的。存证的应用场景有：

数字版权
司法存证
供应链溯源
电子发票
...

存证的作用是：

证明文件在某一时间点确实存在
证明文件在某一时间点确实没有被篡改
证明文件在某一时间点确实由某个人创建

实操

Open a terminal shell on your computer.
Clone the node template repository by running the following command:

git clone https://github.com/substrate-developer-hub/substrate-node-template

Change to the root of the node template directory by running the following command:

    cd substrate-node-template

Create a new branch to contain your work:

    git switch -c my-learning-branch-2024-04-05

Compile the node template by running the following command:

    cargo build --release

In the same terminal where you compiled your node, you can now start the node in development mode by running the following command:

    ./target/release/node-template --dev --tmp

polkadot.js.org/apps 查看

交易前查询状态 None

交易

提交交易

交易后查询状态

问题

编译报错后使用的命令

    cargo clean
    cargo update
    cargo update -p wasm-bindgen
    cargo update -p librocksdb-sys
    cargo update -p schnorrkel@0.11.4
    cargo update -p anstream@0.6.13  -Z sparse-registry