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"))