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
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
- 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
2. 编译报错：error[E0220]: associated type BlockNumber not found for T
解决： 替换T::BlockNumber为BlockNumberFor<T>
