如何使用savedInstanceState在方向更改时保存相机信息

Question

我正在开发一款带有相机意图捕获图像的Android应用程序。我的应用程序不限于任何方向，当用户以纵向开始时，应用程序和应用程序都会崩溃，然后在横向上拍摄图像，然后在横向上按OK。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哪里需要调用保存的实例。

错误是： java.lang.RuntimeException：无法恢复活动{.MainActivity}：java.lang.RuntimeException：传递结果失败ResultInfo {who = null，request = 0，result = -1，data = null}到activity {.MainActivity}：java.lang.NullPointerException：

注意：捕获的图像将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

这个问题的答案是由图像的保存和恢复开放的时候方向更改：

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

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

答案在于s链接： Answer

Answer 2

保存在onSavedInstanceState()状态就像下面提供：

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); 
} 

，然后将其在onCreate()或onRestoreInstanceState()恢复。

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 
    } 
    ... 
} 

onRestoreInstanceState被onStart()后调用，您可以在这里恢复值：

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); 
}