使用系统自带的相册选择器选择单或多张照片

gistfile1.kt

// registerForActivityResult
class MainActivity : AppCompatActivity() {

    companion object {
        private const val TAG = "MainActivity"
    }

    lateinit var viewBinding: ActivityMainBinding

    private val fileChooserContract = registerForActivityResult(ActivityResultContracts.GetContent()) { uri ->
        Log.d(TAG, "onActivityResult: uri $uri")
    }

    private val filesChooserContract = registerForActivityResult(ActivityResultContracts.GetMultipleContents()) { uriList ->
        for (uri in uriList) {
            Log.d(TAG, "onActivityResult: uri $uri")
        }
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        viewBinding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(viewBinding.root)

        viewBinding.btnPick.setOnClickListener {
            fileChooserContract.launch("image/*")
        }

        viewBinding.btnPickMulti.setOnClickListener {
            filesChooserContract.launch("image/*")
        }
    }
}

MainActivity.kt

// startActivityForResult
class MainActivity : AppCompatActivity() {

    companion object {
        private const val TAG = "MainActivity"
        const val REQUEST_CODE_PICK_IMAGE = 1000
        const val REQUEST_CODE_PICK_IMAGES = 1010
    }

    lateinit var viewBinding: ActivityMainBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        viewBinding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(viewBinding.root)

        viewBinding.btnPick.setOnClickListener {
            val intent = Intent(Intent.ACTION_GET_CONTENT)

            intent.type = "image/*"
            intent.putExtra(Intent.EXTRA_LOCAL_ONLY, true)
            
            val chooserIntent = Intent.createChooser(intent, "Select Picture")
            startActivityForResult(chooserIntent, REQUEST_CODE_PICK_IMAGE)
        }

        viewBinding.btnPickMulti.setOnClickListener {
            val intent = Intent(Intent.ACTION_GET_CONTENT)

            intent.type = "image/*"
            intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true)
            intent.putExtra(Intent.EXTRA_LOCAL_ONLY, true)

            val chooserIntent = Intent.createChooser(intent, "Select Picture")
            startActivityForResult(chooserIntent, REQUEST_CODE_PICK_IMAGES)
        }
    }

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)

        if (requestCode == REQUEST_CODE_PICK_IMAGE) {
            if (resultCode == RESULT_OK) {
                data?.data?.let {
                    Log.d(TAG, "onActivityResult: uri $it")
                }
            }
        } else if (requestCode == REQUEST_CODE_PICK_IMAGES) {
            if (resultCode == RESULT_OK) {
                data?.data?.let {
                    Log.d(TAG, "onActivityResult: uri $it")
                }
                data?.clipData?.let { clipData ->
                    for (index in 0 until clipData.itemCount) {
                        val item = clipData.getItemAt(index)

                        Log.d(TAG, "onActivityResult: index $index uri ${item.uri}")
                    }
                }
            }
        }
    }
}