再见startActivityForResult ()

现在AndroidX活动的正确方法是活动结果api，这是谷歌强烈推荐的方法

private val selectImageFromGalleryResult = registerForActivityResult(ActivityResultContracts.GetContent()) { uri: Uri? ->
    uri?.let { previewImage.setImageURI(uri) }
}

需要时只需调用selectImageFromGallery()

private fun selectImageFromGallery() = selectImageFromGalleryResult.launch("image/*")

对于只从本地选择添加这个:

        i.putExtra(Intent.EXTRA_LOCAL_ONLY,true)

这个工作得很好:

    val i = Intent(Intent.ACTION_GET_CONTENT,MediaStore.Images.Media.EXTERNAL_CONTENT_URI)
    i.type = "image/*"
    i.putExtra(Intent.EXTRA_LOCAL_ONLY,true)
    startActivityForResult(Intent.createChooser(i,"Select Photo"),pickImageRequestCode)

再见startActivityForResult ()

现在AndroidX活动的正确方法是活动结果api，这是谷歌强烈推荐的方法

private val selectImageFromGalleryResult = registerForActivityResult(ActivityResultContracts.GetContent()) { uri: Uri? ->
    uri?.let { previewImage.setImageURI(uri) }
}

需要时只需调用selectImageFromGallery()

private fun selectImageFromGallery() = selectImageFromGalleryResult.launch("image/*")

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

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/*")
    }
}

下面是kotlin中util方法的工作代码:

fun launchGalleryWithFragment() {
        val intent = Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI)
        intent.type = "image/*"
        startActivityForResult(Intent.createChooser(intent, "Select Picture"), 1001)
    }

现在重写onActivityResult方法:

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
var path: Uri? = null
        if (requestCode == PICK_IMAGE_REQUEST && resultCode == Activity.RESULT_OK) {
            if(dataIntent == null || dataIntent.data == null){
                return null
            }
            path = dataIntent.data
        }

}