Add study notes for 2025-08-16

Author: AutoBot42

JP3000.md

@@ -15,6 +15,105 @@ INFJ，珠海，数据科学在读，目前在学习ai agent，ai应用开发，
 ## Notes
 
 <!-- Content_START -->
+# 2025-08-16
+
+### 简单Dapp开发
+ 参考课程地址：https://www.youtube.com/watch?v=awQTDVvYyjI
+课程名称：build a Todo App with Solidity, nextjs, Truffle
+该项目主要采用Truffle，考虑后面为适应市场改用为hardhat
+
+前端已简单生成主要是写后端的智能合约
+```solidity
+    // SPDX-License-Identifier: MIT
+    pragma solidity ^0.8.15;
+
+    // task:{ id: 0, taskText: 'clean', isDeleted: false }, 
+    // DEPLOYED Contract Address
+    // ABI 
+
+
+    contract TaskContract {
+    event AddTask(address recipient, uint taskId);
+    event DeleteTask(uint taskId, bool isDeleted);
+
+    struct Task {
+        uint id;
+        string taskText;
+        bool isDeleted;
+    }
+
+    Task[] private tasks;
+    mapping(uint256 => address) taskToOwner;
+    // {0: '0x123124124...'}
+    // {1: '0xabc124124...'}
+
+    function addTask(string memory taskText, bool isDeleted) external {
+        uint taskId = tasks.length;
+        tasks.push(Task(taskId, taskText, isDeleted));
+        taskToOwner[taskId] = msg.sender;
+        emit AddTask(msg.sender, taskId);
+    }
+
+    // get tasks that are mine and not deleted
+    function getMyTasks() external view returns (Task[] memory) {
+        Task[] memory temporary = new Task[](tasks.length);
+        uint counter = 0;
+
+        // temporary [{taskText:"hello", isDeleted:false}, empty]
+        for (uint i=0; i < tasks.length; i++) {
+        if (taskToOwner[i] == msg.sender && tasks[i].isDeleted == false) {
+            temporary[counter] = tasks[i];
+            counter++;
+        }
+        }
+
+        // Resize the temporary array to fit the actual number of tasks
+        Task[] memory result = new Task[](counter);
+        for (uint i = 0; i < counter; i++) {
+        result[i] = temporary[i];
+        }
+        return result;
+    }
+
+    function deleteTask(uint taskId, bool isDeleted) external {
+        if(taskToOwner[taskId] == msg.sender){ 
+        tasks[taskId].isDeleted = isDeleted;
+        emit DeleteTask(taskId, isDeleted);
+        }
+    }
+
+    }
+
+```
+此课程为2022年，truffle配置
+需要在先安装truffle
+```bash
+    npm install truffle -g
+```
+安装后，在项目根目录下执行
+```bash
+    truffle init
+```
+在contract文件夹下创建TaskContract.sol文件，将合约代码复制进去
+在migrations文件夹下创建1_initial_migration.js文件，内容如下
+```javascript
+    const TaskContract = artifacts.require("TaskContract");
+
+    module.exports = function (deployer) {
+    deployer.deploy(TaskContract);
+    };
+```
+再在命令行中输入
+```bash
+    truffle dashboard
+```
+在其中进行钱包连接
+然后用命令
+```bash
+    truffle migrate -- network
+```
+通过钱包确认部署，但是需要ETH的gas费，在想可不可以用测试币？
+
 # 2025-08-15
 
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