Question

我的代码在Activity中有效。但是，我决定将其更改为片段，现在它会从viewswitcher中抛出非法状态异常。无法弄清楚出了什么问题。总之，我有一些用作占位符的图像。单击上载图像按钮时，它将从返回的路径中获取uri，并使用它来替换imageSwitcher中的占位符图像。

以下是代码：

private Button buttonUpload;
private ImageSwitcher imageSwitcher;
private ImageButton imageButton0;
private ImageButton imageButton1;
private ImageButton imageButton2;
private ImageButton imageButton3;
private ImageButton imageButton4;
private ArrayList<String> photoArray;
int counter = 0;
private static int LOAD_IMAGE_RESULTS=1;
private static int PLACEHOLDER_IMAGE = R.drawable.placeholder_2;
int[] imgs = {R.drawable.pic1, R.drawable.pic2, R.drawable.pic3,R.drawable.pic4,R.drawable.pic5};


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
    // TODO Auto-generated method stub

    View rootView = inflater.inflate(R.layout.new_item_fragment_1, container,false);
    return rootView;
}


public void onStart() {
    // TODO Auto-generated method stub
    super.onStart();

    //initialize variables and set default photos
    initVariables();
}




private void initVariables(){   
    //photo array
    photoArray = new ArrayList<String>();

    buttonUpload = (Button) getActivity().findViewById(R.id.button_upload_ni);
    buttonUpload.setOnClickListener(this);

    //image Buttons
    imageButton0 = (ImageButton) getActivity().findViewById(R.id.imageButton0);
    imageButton0.setImageResource(imgs[0]);
    imageButton0.setOnClickListener(this);
    imageButton1 = (ImageButton) getActivity().findViewById(R.id.imageButton1);
    imageButton1.setImageResource(imgs[1]);
    imageButton1.setOnClickListener(this);
    imageButton2 = (ImageButton) getActivity().findViewById(R.id.imageButton2);
    imageButton2.setOnClickListener(this);
    imageButton3 = (ImageButton) getActivity().findViewById(R.id.imageButton3);
    imageButton3.setOnClickListener(this);
    imageButton4 = (ImageButton) getActivity().findViewById(R.id.imageButton4);
    imageButton4.setOnClickListener(this);

    imageSwitcher = (ImageSwitcher) getActivity().findViewById(R.id.image_main_previewer);
    imageSwitcher.setFactory(this);

    //Add animation to the preview
    imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(getActivity(), R.anim.abc_fade_in));
    imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(getActivity(), R.anim.abc_fade_out));

    //set a default placeholder
    imageSwitcher.setImageResource(PLACEHOLDER_IMAGE);
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
     super.onActivityResult(requestCode, resultCode, data);
     System.out.println("Got to beginning of onAct");

    // Here we need to check if the activity that was triggers was the Image Gallery.
    // If it is the requestCode will match the LOAD_IMAGE_RESULTS value.
    // If the resultCode is RESULT_OK and there is some data we know that an image was picked.
    if (requestCode == LOAD_IMAGE_RESULTS && resultCode == Activity.RESULT_OK && data != null) {
        // Let's read picked image data - its URI
        Uri pickedImageUri = data.getData();
        // Let's read picked image path using content resolver
    //    String[] filePath = { MediaStore.Images.Media.DATA };
    //    Cursor cursor = getContentResolver().query(pickedImage, filePath, null, null, null);
   //     cursor.moveToFirst();
   //     String imagePath = cursor.getString(cursor.getColumnIndex(filePath[0]));

        // Now we need to set the GUI ImageView data with data read from the picked file.
     //   uploadView.setImageBitmap(BitmapFactory.decodeFile(imagePath));
        //setNewImage(pickedImageUri);

        String finalPath = getFinalFilePath(pickedImageUri);
        setNewImage(pickedImageUri, finalPath);

        // At the end remember to close the cursor or you will end with the RuntimeException!
 //       cursor.close();

        System.out.println("Got to end of onAct");

    }
}



private void setNewImage(Uri uri, String filePath){
    System.out.println("Got to beginning of setNewImage");

    imageSwitcher.setImageURI(uri);

    //also set the image for the thumb nail
    //int buttonId = getThumbButton();
//  ImageButton changeButton = (ImageButton) getActivity().findViewById(buttonId);
//  changeButton.setImageBitmap(decodeSampledBitmapFromFile(filePath,40,40));

    //finally save the Bitmap
    addPathToArray(filePath);
    System.out.println("Got to end of setNewImage");
}




private void addPathToArray(String filePath){
    //Bitmap tempItemImage = BitmapFactory.decodeFile(filePath);
    System.out.println("Entered addBit");
    photoArray.add(filePath);
    System.out.println("Exit addBit "+photoArray.size());
}




private int getThumbButton(){
    //get the size of the array
    int arraySize = photoArray.size();
    int buttonId = 0;
    System.out.println("Entered getThumb");
    //switch through to find button to change
    switch(arraySize){
    case 0:
        buttonId = R.id.imageButton0;
        break;
    case 1:
        buttonId = R.id.imageButton1;
        break;
    case 2:
        buttonId = R.id.imageButton2;
        break;
    case 3:
        buttonId = R.id.imageButton3;
        break;
    case 4:
        buttonId = R.id.imageButton4;
        break;
    default:;

    }

    return buttonId;
}




private String getFinalFilePath(Uri uri){
    String[] filePath = { MediaStore.Images.Media.DATA };
    Cursor cursor = getActivity().getContentResolver().query(uri, filePath, null, null, null);
    cursor.moveToFirst();
    String imagePath = cursor.getString(cursor.getColumnIndex(filePath[0]));
    cursor.close();

    //Now we need to set the GUI ImageView data with data read from the picked file.
      return imagePath;  
}




@Override
public void onClick(View view) {

    int viewId = view.getId();

    switch(viewId){
    case R.id.button_upload_ni:
        getImageFromGallery();
        break;
    case R.id.imageButton0:
        setImageAtPosition(0);
        break;
    case R.id.imageButton1:
        setImageAtPosition(1);
        break;
    case R.id.imageButton2:
        setImageAtPosition(2);
        break;
    case R.id.imageButton3:
        setImageAtPosition(3);
        break;
    case R.id.imageButton4:
        setImageAtPosition(4);
        break;
    default: //nothing here
        ;
    }

}




private void setImageAtPosition(int position){
//  imageSwitcher.setImageResource(imgs[position]);
//  imageSwitcher.setImageDrawable(Drawable.createFromPath(photoArray.get(position)));
}




private void getImageFromGallery(){
   // Create the Intent for Image Gallery.
   Intent i = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);

   // Start new activity with the LOAD_IMAGE_RESULTS to handle back the results when image is picked from the Image Gallery.
   startActivityForResult(i, LOAD_IMAGE_RESULTS);   
}





@Override
public View makeView() {
    // create view
    System.out.println("Make view called");
    counter++;
    System.out.println("setNewImage counter= "+counter);
    ImageView view = new ImageView(getActivity());
    view.setScaleType(ImageView.ScaleType.FIT_CENTER);
    view.setLayoutParams(new ImageSwitcher.LayoutParams (android.view.ViewGroup.LayoutParams.MATCH_PARENT,android.view.ViewGroup.LayoutParams.MATCH_PARENT));
    view.setBackgroundColor(0xFF000000);
    System.out.println("Make view ending");
    return view;
}




public static Bitmap decodeSampledBitmapFromFile(String filePath, int reqWidth, int reqHeight){

    //first check dimensions with inJustDecodeBounds=true 
    final BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    BitmapFactory.decodeFile(filePath,options);

    //calculate inSampledSize
    options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

    //Decode bitmap with inSampleSize set
    options.inJustDecodeBounds = false;
    return BitmapFactory.decodeFile(filePath, options);
}




public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight){
    //raw height and width of image
    final int height = options.outHeight;
    final int width = options.outWidth;
    int inSampleSize = 1;

    if(height>reqHeight || width > reqWidth){
        final int halfHeight = height/2;
        final int halfWidth = width/2;

        //calculate the highest insamplesize value...
        while((halfHeight/inSampleSize)>reqHeight && (halfWidth/inSampleSize)>reqWidth){
            inSampleSize *=2;
        }
    }
    return inSampleSize;
}

Answer 1

终于明白了。当Activity再次获得焦点时，始终会调用片段的OnStart（）方法。因此，所有视图都会再次初始化。第二次，onActivityResult添加了第三个视图，而不是替换其中一个视图，并抛出了illegalstateexception。要修复它，我只是在onActivityCreated（）方法而不是onStart（）中初始化我的视图;

片段中的ImageSwitcher抛出非法状态异常但在一个活动中工作

1 个答案: