如果你只是寻找图像和多重选择。

看一次https://stackoverflow.com/a/15029515/1136023

这对将来很有帮助。我个人觉得使用MultipleImagePick很棒。

这是一个完整的示例请求权限(如果需要)，从图库中选择图像，然后将图像转换为位图或文件

AndroidManifesh.xml

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

活动

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        button_pick_image.setOnClickListener {
            pickImage()
        }
    }

    private fun pickImage() {
        if (ActivityCompat.checkSelfPermission(this, READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
            val intent = Intent(
                Intent.ACTION_PICK,
                MediaStore.Images.Media.INTERNAL_CONTENT_URI
            )
            intent.type = "image/*"
            intent.putExtra("crop", "true")
            intent.putExtra("scale", true)
            intent.putExtra("aspectX", 16)
            intent.putExtra("aspectY", 9)
            startActivityForResult(intent, PICK_IMAGE_REQUEST_CODE)
        } else {
            ActivityCompat.requestPermissions(
                this,
                arrayOf(Manifest.permission.READ_EXTERNAL_STORAGE),
                READ_EXTERNAL_STORAGE_REQUEST_CODE
            )
        }
    }

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)
        if (requestCode == PICK_IMAGE_REQUEST_CODE) {
            if (resultCode != Activity.RESULT_OK) {
                return
            }
            val uri = data?.data
            if (uri != null) {
                val imageFile = uriToImageFile(uri)
                // todo do something with file
            }
            if (uri != null) {
                val imageBitmap = uriToBitmap(uri)
                // todo do something with bitmap
            }
        }
    }

    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        when (requestCode) {
            READ_EXTERNAL_STORAGE_REQUEST_CODE -> {
                if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    // pick image after request permission success
                    pickImage()
                }
            }
        }
    }

    private fun uriToImageFile(uri: Uri): File? {
        val filePathColumn = arrayOf(MediaStore.Images.Media.DATA)
        val cursor = contentResolver.query(uri, filePathColumn, null, null, null)
        if (cursor != null) {
            if (cursor.moveToFirst()) {
                val columnIndex = cursor.getColumnIndex(filePathColumn[0])
                val filePath = cursor.getString(columnIndex)
                cursor.close()
                return File(filePath)
            }
            cursor.close()
        }
        return null
    }

    private fun uriToBitmap(uri: Uri): Bitmap {
        return MediaStore.Images.Media.getBitmap(this.contentResolver, uri)
    }

    companion object {
        const val PICK_IMAGE_REQUEST_CODE = 1000
        const val READ_EXTERNAL_STORAGE_REQUEST_CODE = 1001
    }
}

演示 https://github.com/PhanVanLinh/AndroidPickImage

感谢mklkj。

这是一个活动版本。

fileChooserContract可以选择一个图像。 filesChooserContract可以选择多张图片。

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/*")
        }
    }
}

由于startActivityForResult()已经废弃，我们可以使用ActivityResultLauncher以以下方式从图库中选择图像:

首先，我们需要定义一个ActivityResultLauncher<String[]>并在onCreate()(用于活动)或onViewCreated()(用于片段)中初始化它

        ActivityResultLauncher<String[]> galleryActivityLauncher = registerForActivityResult(new ActivityResultContracts.OpenDocument(), new ActivityResultCallback<Uri>() {
            @Override
            public void onActivityResult(Uri result) {
                if (result != null) {
                    // perform desired operations using the result Uri
                } else {
                    Log.d(TAG, "onActivityResult: the result is null for some reason");
                }
            }
        });

假设我们需要在点击submitButton时打开图库。

在onClickListener中，我们需要调用

galleryActivityLauncher.launch(new String[]{"image/*"});

这里的技巧是launch()的参数。通过在参数数组中添加"image/*"，我们指定文件资源管理器只加载图像。

OnActivityResult方法已弃用

val singleImageResultLauncher =
            registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
                if (result.resultCode == Activity.RESULT_OK) {
                    // There are no request codes
                    val data: Intent? = result.data
                    val selectedImageUri: Uri? = data?.data
                    if (null != selectedImageUri) {
                        // Get the path from the Uri
                        val path = getPathFromURI(selectedImageUri)
                        findViewById<TextView>(R.id.textView).text = path
                        findViewById<ImageView>(R.id.imageView2).setImageURI(selectedImageUri)
                    }
                }
            }

findViewById<Button>(R.id.oneImageSelectBtn).setOnClickListener {
            val intent = Intent()
            intent.type = "image/*"
            intent.action = Intent.ACTION_GET_CONTENT
            intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, false)
            singleImageResultLauncher.launch(Intent.createChooser(intent, "Select Picture"))

        }

private fun getPathFromURI(uri: Uri?): String {
        var path = ""
        if (contentResolver != null) {
            val cursor = contentResolver.query(uri!!, null, null, null, null)
            if (cursor != null) {
                cursor.moveToFirst()
                val idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DISPLAY_NAME)
                path = cursor.getString(idx)
                cursor.close()
            }
        }
        return path
}

2021 Kotlin解决方案与新版本的Fragment:

dependencies {
  implementation "androidx.fragment:fragment:1.3.3"
}

class YourFragment : Fragment() {

    private val fileChooserContract = registerForActivityResult(ActivityResultContracts.GetContent()) { imageUri ->
        if (imageUri != null) {
            // imageUri now contains URI to selected image
        }
    }

    // ...

    fun openFileChooser() {
        fileChooserContract.launch("image/*")
    }
}