提问者:小点点

android 相机:如果它有额外的内容,则 onActivityResult() 意图为空


在Stack Overflow的所有相关问题中进行了大量搜索,但一无所获之后,请尝试帮助我。

我创建了一个捕捉图片的意图。然后,我在onActivityResult()中看到了不同的行为:如果我没有在Intent中添加任何额外内容(对于小图片),onActivityResult中的Intent是可以的,但是当我在Intent中将额外内容添加到将图片写入文件中时,onActivityCResult中的意图是null

意图创建:

Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// without the following line the intent is ok
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(f));
startActivityForResult(takePictureIntent, actionCode);

为什么是null,怎么解决?


共3个答案

匿名用户

如果您提供< code>MediaStore,我也会遇到同样的情况。EXTRA_OUTPUT,那么intent为null,但是您将在您提供的文件中拥有照片(< code>Uri.fromFile(f))。

如果不指定< code>MediaStore。EXTRA_OUTPUT然后您将有一个包含相机保存照片的文件的uri的意图。

不知道这是不是一个错误,但它就是这样工作的。

EDIT:所以在onActivityResult()中,如果为空,则不再需要检查数据。以下是我的工作经历:

 @Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    switch (requestCode) {
        case PICK_IMAGE_REQUEST://actionCode
            if (resultCode == RESULT_OK && data != null && data.getData() != null) {
                //For Image Gallery
            }
            return;

        case CAPTURE_IMAGE_REQUEST://actionCode
            if (resultCode == RESULT_OK) {
                //For CAMERA
                //You can use image PATH that you already created its file by the intent that launched the CAMERA (MediaStore.EXTRA_OUTPUT)
                return;
            }
    }
}

希望有帮助

匿名用户

用Kotlin编写的示例。您为相机应用程序创建了一个UriCameraFragment保存它,直到相机保存图片后返回,并按照您的预期在onActivityResult中将其返回给您。

充当消费者和相机应用程序之间的中介。将< code>Uri作为输入,并在data Intent中返回它。

class CameraFragment : Fragment() {

    companion object {
        val TAG = CameraFragment::class.java.simpleName

        private val KEY_URI = ".URI"

        fun newInstance(uri: Uri, targetFragment: Fragment, requestCode: Int): CameraFragment {
            val args = Bundle()
            args.putParcelable(KEY_URI, uri)
            val fragment = CameraFragment()
            fragment.arguments = args
            fragment.setTargetFragment(targetFragment, requestCode)
            return fragment
        }
    }

    private lateinit var uri: Uri

    private var fired = false

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        retainInstance = true

        fired = savedInstanceState?.getBoolean("fired") ?: false

        if (!fired) {
            val args = arguments
            uri = args.getParcelable(KEY_URI)

            val i = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
            i.putExtra(MediaStore.EXTRA_OUTPUT, uri)
            i.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION)
            context.grantUriPermission(i, uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION)

            startActivityForResult(i, targetRequestCode)
            fired = true
        }
    }

    override fun onSaveInstanceState(outState: Bundle) {
        super.onSaveInstanceState(outState)
        outState.putBoolean("fired", fired)
    }

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

        if (requestCode == targetRequestCode) {
            context.revokeUriPermission(uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION)

            val newData = Intent()
            newData.data = uri
            targetFragment.onActivityResult(requestCode, resultCode, newData)

            dismiss()
        }
    }

    private fun dismiss() {
        fragmentManager.beginTransaction().remove(this).commit()
    }
}

/** Grant Uri permissions for all camera apps. */
fun Context.grantUriPermission(intent: Intent, uri: Uri, modeFlags: Int) {
    val resolvedIntentActivities = packageManager.queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
    for (resolvedIntentInfo in resolvedIntentActivities) {
        val packageName = resolvedIntentInfo.activityInfo.packageName;
        grantUriPermission(packageName, uri, modeFlags);
    }
}

是应用程序中的一个片段,它将触发相机RC_CAMERA是此操作的请求代码。

val uri = /* Your output Uri. */
val f = CameraFragment.newInstance(uri, this, RC_CAMERA)
fragmentManager.beginTransaction().add(f, CameraFragment.TAG).commit()
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)

    when(requestCode) {
        RC_CAMERA -> {
            if (resultCode == Activity.RESULT_OK) {
                val uri = data?.data
                // Do whatever you need.
            }
        }
    }
}

匿名用户

您在哪里为< code>Uri.fromFile(f)创建了< code>f?

它必须是有效的< code>File对象。请尝试在< code>EXTRA_OUTPUT行之前创建它。

File f = new File("valid path");

试试这样的方法:

File file = new File(dataFile);
Uri outFileUri = Uri.fromFile(file);
Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
intent.putExtra(MediaStore.EXTRA_OUTPUT, outFileUri);
startActivityForResult(intent, TAKE_PHOTO);