Android 相机 OnActivityResult 将照片路径重置为空 [英] Android Camera OnActivityResult resets photo path to null

问题描述

我在朋友 Galaxy S4(GT i9505，Android 5.1)上测试我的应用程序时遇到问题.当为相机意图提供文件 URI 时，OnActivityResult 提供结果 Activity.RESULT_OK 并且路径为 null.它适用于我测试过的大多数其他设备(LG G3、nexus 5...).这是我的代码:

I'm having a problem while testing my app on a friends Galaxy S4 (GT i9505, Android 5.1). When giving a file URI to camera intent, OnActivityResult gives result Activity.RESULT_OK and and the path is null. It is working on most of other devices I tested (LG G3, nexus 5...). This is my code:

GetOutputMediaFile

public File getOutputMediaFile(int type){
    File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM), MediaChooserConstants.folderName);
    if (! mediaStorageDir.exists()){
        if (! mediaStorageDir.mkdirs()){
            return null;
        }
    }

    // Create a media file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    File mediaFile;
    if (type == MediaChooserConstants.MEDIA_TYPE_IMAGE){
        mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_" + timeStamp + ".jpg");
    } else if(type == MediaChooserConstants.MEDIA_TYPE_VIDEO) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator + "VID_" + timeStamp + ".mp4");
    } else {
        return null;
    }
    return mediaFile;
}

OnActivityResult

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == Activity.RESULT_OK) {
        String picturePath = null;
        if (requestCode == MediaChooserConstants.CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE) {
            picturePath = fileUri.getPath(); // <--- fileURI is null
        }
    }
}

DispatchTakePhotoIntent

private void dispatchTakePictureIntent() {
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    File file = Utils.getInstance().getOutputMediaFile(MediaChooserConstants.MEDIA_TYPE_IMAGE);

    fileUri = Uri.fromFile(file); // create a file to save the image
    intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); // set the image file name

    //fileUri is not null here while debugging (../DCIM/.../IMG_XXX.jpg)
    startActivityForResult(intent, MediaChooserConstants.CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);

}

推荐答案

图片保存路径如下:

@Override
protected void onSaveInstanceState(Bundle savedInstanceState) {

    if(mImageCaptureUri!=null)
        savedInstanceState.putString("camera_image", mImageCaptureUri.toString());

    super.onSaveInstanceState(savedInstanceState);
}

并从中检索图像路径:

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {

    if (savedInstanceState != null) {
        if (savedInstanceState.containsKey("camera_image")) {
            mImageCaptureUri = Uri.parse(savedInstanceState.getString("camera_image"));
        }
    }

    super.onRestoreInstanceState(savedInstanceState);
}

这个问题会发生，只有当用户进入相机意图并且当他捕获图像时，当用户从相机意图返回时，托管相机意图的活动才会被破坏或重新创建.

This problem happens, Only when user goes to camera intent and by the time he captures the image the activity on which camera intent was hosted gets destroyed or recreated when user comes back from the camera intent.

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