当方向发生变化时如何使用savedInstanceState保存摄像机信息[重复]

Question

这个问题在这里已有答案：

• When i try to get the Uri from a picture taken with the camera i get null 2回答

我正在开发一款带摄像头意图捕获图像的Android应用程序。我的应用程序不限于任何方向，并且应该同时工作，当用户以纵向开始我的应用程序崩溃，然后以横向拍摄图像并按下风景中的确定。我不想在我的Manifest中使用：android:configChanges="orientation|keyboardHidden|screenSize"，因为我有不同的纵向和横向布局。我试图使用"savedInstanceState"但我没有成功，因为我不知道我需要保存哪些数据以及我需要调用保存的实例。

错误是：

java.lang.RuntimeException: Unable to resume activity {.MainActivity}: java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=0, result=-1, data=null} to activity {.MainActivity}: java.lang.NullPointerException: 

注意：捕获的图像将通过以下方式通过意图发送到另一个活动：

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    ...
}

这是我的代码：

takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (takePictureIntent.resolveActivity(MainActivity.this.getPackageManager()) != null) {
    File exportDir = new File(Environment.getExternalStorageDirectory(), "TempFolder");
    if (!exportDir.exists()) {
        exportDir.mkdirs();
    } else {
        exportDir.delete();
    }
    mTempCameraPhotoFile = new File(exportDir, "/" + UUID.randomUUID().toString().replaceAll("-", "") + ".jpg");
    Log.d(TAG, "path to file: " + "/" + UUID.randomUUID().toString().replaceAll("-", "") + ".jpg");
    takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(mTempCameraPhotoFile));
    startActivityForResult(takePictureIntent, REQUEST_CAMERA);
}

onActivityResult

if (requestCode == REQUEST_CAMERA && resultCode == RESULT_OK) {
    Intent intent = new Intent(MainActivity.this, CameraActivity.class);
    //intent.putExtra("ID_EXTRA", new String[] { bytes.toByteArray(), "Load_Image"});
    intent.putExtra("imageUri", Uri.fromFile(mTempCameraPhotoFile));

    //intent.putExtra("imageUri", outputFileUri);
    intent.putExtra("Title", "Take_Image");
    startActivity(intent);

Answer 1

在onSavedInstanceState()中保存状态，如下所示：

static final String STATE_SCORE = "playerScore";
static final String STATE_LEVEL = "playerLevel";
...


@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
    // Save the user's current game state
    savedInstanceState.putInt(STATE_SCORE, mCurrentScore);
    savedInstanceState.putInt(STATE_LEVEL, mCurrentLevel);


    // Always call the superclass so it can save the view hierarchy state
    super.onSaveInstanceState(savedInstanceState);
}

然后在onCreate()或onRestoreInstanceState()中恢复它。

的onCreate：

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState); // Always call the superclass first


    // Check whether we're recreating a previously destroyed instance
    if (savedInstanceState != null) {
        // Restore value of members from saved state
        mCurrentScore = savedInstanceState.getInt(STATE_SCORE);
        mCurrentLevel = savedInstanceState.getInt(STATE_LEVEL);
    } else {
        // Probably initialize members with default values for a new instance
    }
    ...
}

在onStart()之后调用onRestoreInstanceState，你可以在这里恢复值：

public void onRestoreInstanceState(Bundle savedInstanceState) {
// Always call the superclass so it can restore the view hierarchy
super.onRestoreInstanceState(savedInstanceState);


// Restore state members from saved instance
mCurrentScore = savedInstanceState.getInt(STATE_SCORE);
mCurrentLevel = savedInstanceState.getInt(STATE_LEVEL);
}

Answer 2

这个问题的答案是在方向改变时保存和恢复图像的Uri：

protected void onSaveInstanceState(Bundle outState)
    {
        outState.putParcelable("outputFileUri", outputFileUri);
    }

if (savedInstanceState != null)
        {
            outputFileUri= savedInstanceState.getParcelable("outputFileUri");
        }

答案在这个链接：Answer