import android.app.AlertDialog import android.os.Bundle import androidx.activity.OnBackPressedCallback import androidx.appcompat.app.AppCompatActivity import androidx.lifecycle.lifecycleScope import androidx.activity.viewModels import kotlinx.coroutines.CancellationException import kotlinx.coroutines.Dispatchers import kotlinx.coroutines.launch import kotlinx.coroutines.withContext import timber.log.Timber class MainActivity : AppCompatActivity() { private val viewModel: MainViewModel by viewModels() private val TAG = "MainActivity" private val backCallback = object : OnBackPressedCallback(true) { override fun handleOnBackPressed() { handleAppExit() } } override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) onBackPressedDispatcher.addCallback(this, backCallback) } private fun handleAppExit() { backCallback.isEnabled = false lifecycleScope.launch(Dispatchers.IO) { try { //判断是否需要提示 val isBeConfirm = true if (isBeConfirm) { withContext(Dispatchers.Main) { showExitConfirmationDialog() } } else { withContext(Dispatchers.Main) { finish() } } } catch (e: Exception) { Timber.tag(TAG).e(e) if (e !is CancellationException) { withContext(Dispatchers.Main) { finish() } } } finally { withContext(Dispatchers.Main) { backCallback.isEnabled = true } } } } private fun showExitConfirmationDialog() { AlertDialog.Builder(this) .setTitle("还不能退出") .setMessage("退出后，会如何？") .setPositiveButton("继续退出") { dialog, which -> finish() } .setNegativeButton("取消") { dialog, which -> dialog.dismiss() } .setCancelable(false) .show() } }

微信小程序-分包 分包后-分包内的JS文件还是会被打包入主包的vendor.js,导致超出2M限制 项目根目录创建vue.config.js module.exports = { configureWebpack: { optimization: { splitChunks: { cacheGroups: { subPackageA: { name: 'subPackageName/vendor', test: /[\\/]node_modules[\\/](library-name)[\\/]/, chunks: 'all', priority: 10, enforce: true } } } } } }; manifest.json 增加配置 "mp-weixin" : { "optimization" : { "subPackages" : true } },

Android 蓝牙连接 RxAndroidBle连接库只能扫描出Ble类型设备 使用原生Android扫描出设备获取Mac地址，然后用RxAndroidBle连接 fun scanBleDeviceNative(deviceName: String) { val adapter = (context.getSystemService(Context.BLUETOOTH_SERVICE) as android.bluetooth.BluetoothManager).adapter if (adapter == null || !adapter.isEnabled) { Timber.tag(TAG).w("蓝牙未开启") return } // 如果之前正在扫描，先取消 if (adapter.isDiscovering) adapter.cancelDiscovery() // 监听经典蓝牙发现广播 val receiver = object : BroadcastReceiver() { override fun onReceive(context: Context, intent: Intent) { when (intent.action) { BluetoothDevice.ACTION_FOUND -> { val device: BluetoothDevice? = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) { intent.getParcelableExtra( BluetoothDevice.EXTRA_DEVICE, BluetoothDevice::class.java ) } else { @Suppress("DEPRECATION") intent.getParcelableExtra<BluetoothDevice>(BluetoothDevice.EXTRA_DEVICE) } device?.let { val name = it.name ?: return if (name.contains(deviceName, ignoreCase = true)) { Timber.tag(TAG) .d("找到设备: $name ${device.address}") // 将经典 BluetoothDevice 转为 RxBleDevice 对象 val bleDevice = rxBleClient.getBleDevice(device.address) // 连接 到设备.... // 停止扫描 try { adapter.cancelDiscovery() } catch (_: Exception) { } context.unregisterReceiver(this) } } } BluetoothAdapter.ACTION_DISCOVERY_FINISHED -> { Timber.tag(TAG).d("扫描结束") context.unregisterReceiver(this) } } } } val filter = IntentFilter(BluetoothDevice.ACTION_FOUND).apply { addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED) } context.registerReceiver(receiver, filter) // 启动蓝牙扫描 adapter.startDiscovery() Timber.tag(TAG).d("开始扫描") // 设置 10 秒超时停止扫描 Handler(Looper.getMainLooper()).postDelayed({ try { if (adapter.isDiscovering) adapter.cancelDiscovery() Timber.tag(TAG).d("扫描超时，已停止") context.unregisterReceiver(receiver) } catch (_: Exception) { } }, 10_000) }

求和符号 ($\sum$) 的含义 这个公式片段的完整形式通常是这样的： $$ \sum_{i=1}^{N} f(i) $$ 符号 含义 $\sum$ (Sigma) 求和符号。表示将一系列数值加起来（累加）。 $i=1$ 起始索引。表示求和从 $i$ 等于 1 开始。 $N$ 结束索引。表示求和到 $i$ 等于 $N$ 结束。 $f(i)$ 求和项。表示每次累加的具体数值或表达式。 用通俗的话来说，它的意思是： “将 $f(i)$ 这个表达式，从 $i=1$ 开始，一直算到 $i=N$ 结束，然后把所有结果加起来。” 示例 如果 $N=4$，且求和项是 $f(i) = i^2$，那么公式的展开式就是： $$ \sum_{i=1}^{4} i^2 = 1^2 + 2^2 + 3^2 + 4^2 = 1 + 4 + 9 + 16 = 30 $$

scp -P 22 /path/file sshuser@hostname:/path -P 大写P,后是ssh端口 需要传到服务器的文件路径 sshuser: 服务器ssh用户 hostname: 服务器IP

Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem\LongPathsEnabled (Type: REG_DWORD) 设置为1

" 语法高亮 syntax enable syntax on set t_Co=256 " 背景 set background=dark "colorscheme dark set termguicolors set backspace=indent,eol,start set clipboard=unnamed set mouse=a set title set autoread set history=1000 set formatoptions+=j "set shell set tabstop=4 set expandtab set shiftwidth=4 set softtabstop=4 set modelines=1 filetype plugin on filetype indent on set autoindent set shiftround set smarttab set number set showcmd set showmatch set cursorline set wildmenu set lazyredraw set complete-=i "set fillchars+=vert:| set laststatus=2 set ruler set display+=lastline set encoding=utf-8 set linebreak "set scrolloff set sidescrolloff=5 set wrap set ignorecase set incsearch set hlsearch set smartcase set noerrorbells set foldmethod=indent set foldnestmax=10 set foldenable nnoremap <space> za set foldlevelstart=10 set nobackup set noswapfile

PyenvWindows安装配置 1.Power Shell脚本安装pyenv-win Invoke-WebRequest -UseBasicParsing -Uri https://raw.githubusercontent.com/pyenv-win/pyenv-win/master/install-pyenv-win.ps1 -OutFile install-pyenv-win.ps1 Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser .\install-pyenv-win.ps1 2.重新打开PowerShell 设置国内源环境变量 [Environment]::SetEnvironmentVariable('PYTHON_BUILD_MIRROR_URL','https://mirrors.huaweicloud.com/python/','User') 更新源 pyenv update 3.安装python pyenv install 3.10.11

Win10安装MySQl8+服务 1.软件路径如D:\soft\mysql-8.4 2.根目录配置my.ini [mysqld] # 设置端口 同一机器设置不同端口 port = 3306 # 设置mysql的安装目录 basedir= D:/soft/mysql-8.4 # 设置mysql数据库的数据的存放目录 datadir= D:/soft/mysql-8.4/data # 允许最大连接数 max_connections=20 # 创建新表时将使用的默认存储引擎 default-storage-engine=INNODB mysql_native_password=ON log-bin=mysql-bin gtid-mode=on log_replica_updates=true enforce-gtid-consistency=true sync_binlog=0 binlog-checksum=CRC32 source_verify_checksum=1 replica_sql_verify_checksum=1 binlog-rows-query-log_events=1 sync_source_info=1 #expire_logs_days=5 max_binlog_size=1024M # 主从服务ID主=1 其他递增 server-id=1 # #masterA自增长ID #奇数ID #偶数ID auto_increment_offset = 1 auto_increment_increment = 2 replicate-ignore-db = mysql replicate-ignore-db = information_schema replicate-ignore-db = performance_schema replicate-ignore-db = sys #skip-character-set-client-handshake #忽略应用程序想要设置的其他字符集 init-connect='SET NAMES UTF8MB4' #连接时执行的SQL character-set-server=UTF8MB4 #服务端默认字符集 wait_timeout=1800 #请求的最大连接时间 interactive_timeout=1800 #和上一参数同时修改才会生效 #sql_mode=STRICT_TRANS_TABLES #sql模式 max_allowed_packet = 10M bulk_insert_buffer_size = 8M #skip-name-resolve slow_query_log=1 long_query_time = 6 slow_query_log_file=slow-query.log innodb_flush_log_at_trx_commit = 2 innodb_log_buffer_size = 16M [myisamchk] key_buffer_size = 20M sort_buffer_size = 20M read_buffer = 2M write_buffer = 2M [mysqlhotcopy] interactive-timeout [mysqldump] quick max_allowed_packet = 16M 3.安装脚本install.bat @echo off :: MySQL 安装目录 set MYSQL_HOME=D:/soft/mysql-8.4 set DATADIR=%MYSQL_HOME%/data echo 停止旧服务（如果存在）... sc query MySQL84 >nul 2>nul if %errorlevel%==0 ( net stop MySQL84 sc delete MySQL84 ) echo 删除旧的数据目录... rmdir /S /Q "%DATADIR%" mkdir "%DATADIR%" echo 初始化 MySQL 数据库（无密码）... "%MYSQL_HOME%/bin/mysqld.exe" --initialize-insecure --basedir="%MYSQL_HOME%" --datadir="%DATADIR%" echo 安装 MySQL 服务 (MySQL84)... "%MYSQL_HOME%/bin/mysqld.exe" --install MySQL84 echo 启动 MySQL 服务... net start MySQL84 echo 设置 root 密码为 123456... "%MYSQL_HOME%/bin/mysql.exe" -u root --execute="ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '123456'; FLUSH PRIVILEGES;" echo MySQL 8.4 安装完成，root 密码已设置为 123456 pause