typecho服务器重启后出现502问题 重新启动php-fpm就好了systemctl restart php-fpm

Room数据库Schema export Error 在使用Android Room数据库的时候报错了：Schema export directory is not provided to the annotation processor so we cannot export the schema. You can either provide `room.schemaLocation` annotation processor argument OR set exportSchema to false.如果您不需要检查架构并且想要摆脱警告，只需将exportSchema = false添加到RoomDatabase中，如下所示:@Database(entities = { YourEntity.class }, version = 1, exportSchema = false) public abstract class AppDatabase extends RoomDatabase { //... }另一种方法是在应用模块的build.gradle文件中，将此文件添加到defaultConfig部分(在android部分下面)。这会将架构写到项目文件夹的schemas子文件夹中。android { // ... (compileSdkVersion, buildToolsVersion, etc) defaultConfig { // ... (applicationId, miSdkVersion, etc) kapt { arguments { arg("room.schemaLocation","$projectDir/schemas".toString()) } } } buildTypes { // ... (buildTypes, compileOptions, etc) } } //...以上是Kotlin,如果是Java：android { // ... (compileSdkVersion, buildToolsVersion, etc) defaultConfig { // ... (applicationId, miSdkVersion, etc) javaCompileOptions { annotationProcessorOptions { arguments = ["room.schemaLocation":"$projectDir/schemas".toString()] } } } // ... (buildTypes, compileOptions, etc) }当执行项目后，在Android Studio 的Project视图下，查看项目，会发现Module生成了一个schemas的文件夹，打开.json文件看起来像这样：{ "formatVersion": 1, "database": { "version": 1, "identityHash":"6240057b6178b803a0bf9915edf969e3", "entities": [ { "tableName":"sms_table", "createSql":"CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER PRIMARY KEY AUTOINCREMENT, `message` TEXT, `date` INTEGER, `client_id` INTEGER)", "fields": [ { "fieldPath":"id", "columnName":"id", "affinity":"INTEGER" }, { "fieldPath":"message", "columnName":"message", "affinity":"TEXT" }, { "fieldPath":"date", "columnName":"date", "affinity":"INTEGER" }, { "fieldPath":"clientId", "columnName":"client_id", "affinity":"INTEGER" } ], "primaryKey": { "columnNames": [ "id" ], "autoGenerate": true }, "indices": [], "foreignKeys": [] } ], "setupQueries": [ "CREATE TABLE IF NOT EXISTS room_master_table (id INTEGER PRIMARY KEY,identity_hash TEXT)", "INSERT OR REPLACE INTO room_master_table (id,identity_hash) VALUES(42, "6240057b6178b803a0bf9915edf969e3")" ] } }

Android改变状态栏文本颜色(WHITE/BLACK) API> = 23从API v23及更高版本开始，可以将以下内容添加到AppTheme styles.xml中：解决方案1// View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR: 将状态栏的文字设置为黑色 window.decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR解决方案1<item name="android:statusBarColor">@color/colorPrimaryDark</item> <item name="android:windowLightStatusBar">true</item>当android:windowLightStatusBar设置为true，状态栏文字颜色将能够可以看出，当状态栏的颜色是白色的，而当android:windowLightStatusBar设置为false，状态栏文字颜色将被设计在状态栏的颜色是可以看到暗。API <23在Android中无法更改状态栏的颜色。可以在应用程序中设置状态栏的背景色val window: Window = activity.getWindow() // clear FLAG_TRANSLUCENT_STATUS flag: window.clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS) // add FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS flag to the window window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS) // finally change the color window.setStatusBarColor(ContextCompat.getColor(activity,R.color.my_statusbar_color))https://developer.android.google.cn/reference/android/view/Window.html#setStatusBarColor(int)

java里的static代码块怎么转成对应的kotlin代码？ JAVA:class Test { static { // 启动时执行的代码 } }Kotlin:companion object { init { // 启动时执行的代码 } }

onActivityResult过时了，registerForActivityResult使用方法 最常用的写法registerForActivityResult( ActivityResultContracts.StartActivityForResult() ) { result -> val data = result.data val resultCode= result.resultCode val extra = data?.getStringExtra("extra") }.launch(Intent(this, MainActivity::class.java))除了基本用法，ActivityResultContracts还提供了一些ActivityResultContract的实现类，以便进行其他的操作:RequestMultiplePermissions : 多个权限请求RequestPermission : 单个权限请求TakePicturePreview : 拍照预览TakePicture : 拍照TakeVideo : 摄像PickContact : 选择联系人GetContent : 获取各种文件的UriGetMultipleContents : 获取多个各种文件的UriOpenDocument : 打开文件OpenMultipleDocuments : 打开多个文件OpenDocumentTree : 打开文件夹CreateDocument : 创建文件打开相机拍照:registerForActivityResult(ActivityResultContracts.TakePicturePreview()){ // 返回bitmap }.launch(null)获取单个/多个权限请求： // 单个权限获取 registerForActivityResult(ActivityResultContracts.RequestPermission()) { if (it) {//同意权限 } else {//拒绝权限 } }.launch(Manifest.permission.WRITE_EXTERNAL_STORAGE) // 多个权限获取 var permissions: Array<String> = arrayOf( Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.CAMERA ) registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { if (it[Manifest.permission.WRITE_EXTERNAL_STORAGE]!!) {// 同意 } else {// 拒绝 } if (it[Manifest.permission.CAMERA]!!) {// 同意 } else {// 拒绝 } }.launch(permissions)查询联系人信息：registerForActivityResult(ActivityResultContracts.PickContact()){ if(it != null){ val cursor = contentResolver.query(it, null, null, null, null) cursor?.run { if(cursor.moveToFirst()){ val name = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME)) } } } }.launch(null)选取文件：registerForActivityResult(ActivityResultContracts.OpenDocument()){ // 获取的文件uri }.launch(arrayOf("image/*","text/plain"))

Caused by: java.lang.IllegalStateException: Only fullscreen opaque activities can request orientation android 8.0 (API=26) 出现的问题解决方法：去掉android:screenOrientation;android:windowIsTranslucent 改为false; 如果需要透明的设置加上android:windowDisablePreview =true;在项目res目录下创建values-v26/styles.xml<?xml version="1.0" encoding="utf-8"?> <resources> <style name="AppTheme.Start" parent="AppTheme"> <item name="android:windowActionBar">false</item> <item name="android:windowNoTitle">true</item> <item name="android:windowFullscreen">true</item> <!-- 适配android手机系统8.0(api26)，Only fullscreen opaque activities can request orientation --> <!--用背景图消除启动白屏--> <item name="android:windowBackground">@mipmap/background</item> <item name="android:windowIsTranslucent">false</item> <item name="android:windowDisablePreview">true</item> </style> </resources>

Retrofit传参Map<String,Any>报错 在使用retrofit请求接口时报错了，参数：Map<String,Any>Parameter type must not include a type variable or wildcard: java.util.Map<java.lang.String, ?>问题是在值类型为Any,在JAVA里这个值就Object,查在kotlin里就变成*号了，Retrofit不能识别。只需要添加@JvmSuppressWildcards接口即可@JvmSuppressWildcards internal interface WebService { ... }

Waiting for another flutter command to release the startup lock 运行flutter devices出现：Waiting for another flutter command to release the startup lock解决方法:1.打开flutter的安装目录/bin/cache/2.删除lockfile文件3.重启AndroidStudio

android5遇到INSTALL_FAILED_DEXOPT 解决办法 最近写个项目，在用一台android5.0.2的旧手机测试时出现INSTALL_FAILED_DEXOPT,看图：点击ok后可以看到报错:起初以为是手机内存不足，卸载了多个app后无效，恢复出厂设置也一样无效。在网上找了好几天都无头绪，直到我看到这样一片文章：但我这里并没有用到kotlin协程,于是我移除了kotlin-android-extensions，最还是一样无效，为了方便，重新新建了一个项目。然后一个一个加进去试，最后发现"androidx.room:room-ktx"加入后就出现以上错误，既然找到了错误来源，后面的问题就好解决了。

Android唤起微信扫一扫 fun scanQR() { try { val intent = context.packageManager.getLaunchIntentForPackage("com.tencent.mm") intent!!.putExtra("LauncherUI.From.Scaner.Shortcut", true) context.startActivity(intent) } catch (e: Exception) { e.printStackTrace() } }