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

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
        }

}

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/*")

绝对的。试试这个:

Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE);

不要忘记创建常量PICK_IMAGE，这样当用户从图库中返回时，你就可以识别出来:

public static final int PICK_IMAGE = 1;

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data)
{
    if (requestCode == PICK_IMAGE) {
        //TODO: action
    }
}

这就是我对图片库的称呼。把它放进去，看看是否对你有用。

编辑:

这会打开Documents应用程序。允许用户使用他们可能已经安装的任何图库应用程序:

    Intent getIntent = new Intent(Intent.ACTION_GET_CONTENT);
    getIntent.setType("image/*");

    Intent pickIntent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
    pickIntent.setType("image/*");

    Intent chooserIntent = Intent.createChooser(getIntent, "Select Image");
    chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Intent[] {pickIntent});

    startActivityForResult(chooserIntent, PICK_IMAGE);

有时，您无法从所选择的图片中获取文件。 这是因为选择一个来自谷歌+，Drive, Dropbox或任何其他提供商。

最好的解决方案是让系统通过Intent来选择内容。ACTION_GET_CONTENT并使用内容提供程序获取结果。

您可以按照下面的代码或查看我更新的要点。

public void pickImage() {
  Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
  intent.setType("image/*");
  startActivityForResult(intent, PICK_PHOTO_FOR_AVATAR);
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == PICK_PHOTO_FOR_AVATAR && resultCode == Activity.RESULT_OK) {
        if (data == null) {
            //Display an error
            return;
        }
        InputStream inputStream = context.getContentResolver().openInputStream(data.getData());
        //Now you can do whatever you want with your inpustream, save it as file, upload to a server, decode a bitmap...
    }
}

Kotlin:当你想提示用户时，打开ACTION_GET_CONTENT事件:

val intent = Intent(Intent.ACTION_GET_CONTENT).apply { type = "image/*" }
startActivityForResult(intent, 9998)

当用户选择了一张图片后，在Activity的onActivityResult函数中处理该事件。作为一个例子，我在一个ImageView中显示它，并将它存储在应用程序缓存中:

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
    if (requestCode == 9998) {
        val uri: Uri = data?.data ?: return
        val bytes = contentResolver.openInputStream(uri)?.readBytes() ?: return
        imageView.setImageBitmap(BitmapFactory.decodeByteArray(bytes, 0, bytes.size))
        File("$cacheDir/imgPicked").writeBytes(bytes)  // if needed: store to cache
    }
}

理想情况下，将9998替换为应用程序使用的一些内部请求代码。这只是为了区分回调与您自己的请求。

与getParcelable("data")不同，它不需要任何权限。

注意，这不会处理设置它的图像上的Exif旋转位，因此一些图像最终会出现不正确的方向(Kotlin解决方案)。