如何獲取 Substrate 中的當前區塊號？

Question

我的問題是：

1. 我如何捕獲當前塊號？
2. 如何將當前塊號轉換為 u32？

我正在嘗試在模板托盤內編寫一個 function，它采用 u32（輸入參數）並將該數字添加到當前塊號。

#[pallet::weight(10_000 + T::DbWeight::get().writes(1))]
    pub fn revoke(origin: OriginFor<T>, number: u32) -> DispatchResult {
        let caller = ensure_signed(origin)?;

        // GET CURRENT BLOCK NUMBER
        // CONVERT CURRENT BLOCK NUMBER TYPE TO U32
        // TARGET_BLOCK = CURRENT_BLOCK_NUMBER + NUMBER
        // STORE TARGET_BLOCK

        Ok(())
    }

我已閱讀以下文檔（以及更多文檔），但無法使代碼正常工作。

• https://substrate.dev/rustdocs/latest/sp_runtime/offchain/storage_lock/trait.BlockNumberProvider.html#tymethod.current_block_number
• https://substrate.dev/rustdocs/latest/frame_system/pallet/struct.Pallet.html#method.current_block_number
• 如何將塊號轉換為基板模塊中的 Integer 類型？
• https://medium.com/paritytech/utxo-on-substrate-7f0e0576768e

這是我的嘗試列表：

let y = System::block_number() as u32;
let z = sp_std::alloc::System::block_num() as u32;
let p = Self::block_number();
let h = BlockNumberProvider::current_block_number();
let h: BlockNumberFor<T> = BlockNumberProvider::current_block_number();
let p = BlockNumberProvider::current_block_number() as u32;
target_block = target_block + p;
let x = <T as sp_runtime::offchain::storage_lock::BlockNumberProvider>::current_block_number();
let x = <T as BlockNumberProvider>::current_block_number();
let j = frame_system::Pallet<Config>::block_number();
target_block = target_block + h;
let y = Self::BlockNumber;
let yy = <T as frame_system::Config>::BlockNumber;
let xc = frame_system::block_number();
let current_block = System::block_number()
.saturated_into::<u64>()
.saturating_sub(1);
let u = Number::<T>::get(T::BlockNumber);
let w = T::BlockNumber::block_number();
let n = <T as frame_system::Config>::BlockNumber::block_number();
let m = frame_system::<T>::BlockNumber;
let un = BlockNumberFor;
let current_block_number: u32 = <frame_system::Pallet<T>>::block_number();
let now_block_number = <frame_system::Module<T>>::block_number();
let now_block_number = <frame_system::Pallet<T>>::block_number();
let now_block_number_b: <T as frame_system::Config>::BlockNumber = <frame_system::Pallet<T>>::block_number();
T::BlockNumber;
let xp = now_block_number_b + 10;
let h: BlockNumberFor<T> = BlockNumberProvider::current_block_number();
let x: <T as Config>::BlockNumber = BlockNumberProvider::current_block_number();
let x = frame_system::Config::block_number();
let c = block_number();
let v = <T as frame_system::Config>::BlockNumber;
let x = block;
let q = block.into();
let x: Number<T> = block.into();
let f: u32 = x.into();
let v = 10.into();
let w: BlockNumber_<T> = block.into();
let target_block = target_block + f;
let current_block_number: Number<T> = <frame_system::Pallet<T>>::block_number();
let h: BlockNumberFor<T> = BlockNumberProvider::current_block_number();
let x: BlockNumber_<T> = frame_system::pallet::Pallet::current_block_number();
let y: BlockNumberFor<T> = frame_system::pallet::Pallet::current_block_number();
let z: T::BlockNumber = frame_system::pallet::Pallet::current_block_number();

如果您能提供任何幫助，我將不勝感激。

Answer 1

這是工作代碼：

#[pallet::weight(10_000 + T::DbWeight::get().writes(1))]
    pub fn set_block_delay(origin: OriginFor<T>, block: T::BlockNumber) -> DispatchResult {
        let caller = ensure_signed(origin)?;
        
        let current_block_number = <frame_system::Pallet<T>>::block_number();

        let block_delay: u32 = 10;

        let target_block = current_block_number + block_delay.into();

        ensure!(target_block < block, "fail");

        Ok(())
    }