html5购物网站模板,艾佳工业设计,撰写网络推广策划案,如何做网站优惠券推广动态调用的作用 类似于其他语言的反射能够开发框架性代码 Call调用语法 (bool success, bytes data) address.call(bytes calldata)call是address的方法call返回值(bool success, bytes data)忽视返回值success#xff0c;会造成严重问题 calldata的结构 call的…动态调用的作用 类似于其他语言的反射能够开发框架性代码 Call调用语法 (bool success, bytes data) address.call(bytes calldata)call是address的方法call返回值(bool success, bytes data)忽视返回值success会造成严重问题 calldata的结构 call的参数是calldatacalldata的前四个字节是selector剩下的是参数编码selector bytes(keccak256())keccak256:哈希sha3-256 Abi工具函数 calldata abi.encodeWithSignature(sig, ps)–会用返回值解码abi.decode(bytes) 编码、解码 decoder.sol // SPDX-License-Identifier: MIT pragma solidity ^0.8.17;contract AbiDecode {struct MyStruct {string name;uint[2] nums;}function encode(uint x,address addr,uint[] calldata arr,MyStruct calldata myStruct) external pure returns (bytes memory) {return abi.encode(x, addr, arr, myStruct);}function decode(bytes calldata data)externalpurereturns (uint x, address addr, uint[] memory arr, MyStruct memory myStruct){// (uint x, address addr, uint[] memory arr, MyStruct myStruct) ...(x, addr, arr, myStruct) abi.decode(data, (uint, address, uint[], MyStruct));} } 效果 Callee.sol // SPDX-License-Identifier: GPL-3.0pragma solidity 0.8.2 0.9.0;contract Callee {uint public x;function setX(uint _x)public returns(uint){x _x;return x;} }Caller.sol // SPDX-License-Identifier: GPL-3.0pragma solidity 0.8.2 0.9.0;contract Caller{address calleeAddress;uint public xx;constructor(address _calleeAddress){calleeAddress _calleeAddress;}function setCalleeX(uint _x)public{bytes memory cd abi.encodeWithSignature(setX(uint256), _x);(bool suc, bytes memory rst) calleeAddress.call(cd);if(!suc){revert(call failed);}(uint x) abi.decode(rst, (uint));xx x;} }效果