如何使用android中的view pager获取图像文件名

时间：2013-11-11 07:18:05

标签： android android-image

我是android新手。我看到一个来自互联网的代码，用于全屏显示存储在SD卡上的图像。它对我来说很好。来自SD卡中我的照片文件夹的图像正在显示并且滑动得很好。现在我想在sqlite中保存图像文件名。但是我无法获得图像文件名。如果有人请帮助我。 我的活动代码是.... FullScreenViewActivity.java 

public class FullScreenViewActivity extends Activity{

private Utils utils;
private FullScreenImageAdapter adapter;
private ViewPager viewPager;
Button save;
ArrayList<String>path=new ArrayList<String>();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_fullscreen_view);

    viewPager = (ViewPager) findViewById(R.id.pager);
    save=(Button)findViewById(R.id.save);
    utils = new Utils(getApplicationContext());
    //save.clearAnimation();
    Intent i = getIntent();
    int position = i.getIntExtra("position", 0);

    adapter = new FullScreenImageAdapter(FullScreenViewActivity.this,
            utils.getFilePaths());

    viewPager.setAdapter(adapter);

    // displaying selected image first
    viewPager.setCurrentItem(position);
    save.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            String name="";
            try{
            name=utils.getFileName();
            }catch(Exception e){
                e.printStackTrace();
            }
            //for(int i=0;i<path.size();i++)
            //{
                //sb.append(path.get(i).toString());
            //  name=path.get(i).toString();
            //}
            Toast.makeText(getApplicationContext(), name, Toast.LENGTH_LONG).show();

        }
    });
    viewPager.setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            // TODO Auto-generated method stub
            //String name=utils.getResources().getResourceName(R.id.pager);
            path=utils.getFilePaths();

            return false;
        }
    });

    //String name=getResources().getResourceName(position);
    //Toast.makeText(getApplicationContext(), ""+position, Toast.LENGTH_LONG).show();
}
}

GridViewActivity.java 

public class GridViewActivity extends Activity {

private Utils utils;
private ArrayList<String> imagePaths = new ArrayList<String>();
private GridViewImageAdapter adapter;
private GridView gridView;
private int columnWidth;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_grid_view);

    gridView = (GridView) findViewById(R.id.grid_view);

    utils = new Utils(this);

    // Initilizing Grid View
    InitilizeGridLayout();

    // loading all image paths from SD card
    imagePaths = utils.getFilePaths();

    // Gridview adapter
    adapter = new GridViewImageAdapter(GridViewActivity.this, imagePaths,
            columnWidth);

    // setting grid view adapter
    gridView.setAdapter(adapter);
}

private void InitilizeGridLayout() {
    Resources r = getResources();
    float padding = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
            AppConstant.GRID_PADDING, r.getDisplayMetrics());

    columnWidth = (int) ((utils.getScreenWidth() - ((AppConstant.NUM_OF_COLUMNS + 1) * padding)) / AppConstant.NUM_OF_COLUMNS);

    gridView.setNumColumns(AppConstant.NUM_OF_COLUMNS);
    gridView.setColumnWidth(columnWidth);
    gridView.setStretchMode(GridView.NO_STRETCH);
    gridView.setPadding((int) padding, (int) padding, (int) padding,
            (int) padding);
    gridView.setHorizontalSpacing((int) padding);
    gridView.setVerticalSpacing((int) padding);
}

}

FullScreenImageAdapter.java 

public class FullScreenImageAdapter extends PagerAdapter {

private Activity _activity;
private Context c;
private Utils utils;
private ArrayList<String> _imagePaths; 
private LayoutInflater inflater;
String name="";

// constructor
public FullScreenImageAdapter(Activity activity,
        ArrayList<String> imagePaths) {
    this._activity = activity;
    this._imagePaths = imagePaths;
    //utils=new Utils(this);
}

@Override
public int getCount() {
    return this._imagePaths.size();
}

@Override
public boolean isViewFromObject(View view, Object object) {
    return view == ((RelativeLayout) object);
}

@Override
public Object instantiateItem(ViewGroup container, int position) {
    TouchImageView imgDisplay;
    Button btnClose;

    inflater = (LayoutInflater) _activity
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View viewLayout = inflater.inflate(R.layout.layout_fullscreen_image, container,
            false);

    imgDisplay = (TouchImageView) viewLayout.findViewById(R.id.imgDisplay);
   // btnClose = (Button) viewLayout.findViewById(R.id.btnClose);

    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inPreferredConfig = Bitmap.Config.ARGB_8888;
    Bitmap bitmap = BitmapFactory.decodeFile(_imagePaths.get(position), options);
    imgDisplay.setImageBitmap(bitmap);
    //name=""+imgDisplay.getId();
    // close button click event

    /*  btnClose.setOnClickListener(new View.OnClickListener() {            
        @Override
        public void onClick(View v) {

            //_activity.finish();
            //Toast.makeText(c, "kkkk", Toast.LENGTH_LONG).show();
        }
    }); 


    btnClose.setOnCheckedChangeListener(new OnCheckedChangeListener() {

        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            // TODO Auto-generated method stub
            if(buttonView.isChecked())
            {
                Toast.makeText(c, "kkkk", Toast.LENGTH_LONG).show();
            }

        }
    });
    */

    ((ViewPager) container).addView(viewLayout);

    return viewLayout;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    ((ViewPager) container).removeView((RelativeLayout) object);

}

}

GridViewImageAdapter.java 

public class GridViewImageAdapter extends BaseAdapter {

private Activity _activity;
private ArrayList<String> _filePaths = new ArrayList<String>();
private int imageWidth;

public GridViewImageAdapter(Activity activity, ArrayList<String> filePaths,
        int imageWidth) {
    this._activity = activity;
    this._filePaths = filePaths;
    this.imageWidth = imageWidth;
}

@Override
public int getCount() {
    return this._filePaths.size();
}

@Override
public Object getItem(int position) {
    return this._filePaths.get(position);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ImageView imageView;
    if (convertView == null) {
        imageView = new ImageView(_activity);
    } else {
        imageView = (ImageView) convertView;
    }

    // get screen dimensions
    Bitmap image = decodeFile(_filePaths.get(position), imageWidth,
            imageWidth);

    imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
    imageView.setLayoutParams(new GridView.LayoutParams(imageWidth,
            imageWidth));
    imageView.setImageBitmap(image);

    // image view click listener
    imageView.setOnClickListener(new OnImageClickListener(position));

    return imageView;
}

class OnImageClickListener implements OnClickListener {

    int _postion;

    // constructor
    public OnImageClickListener(int position) {
        this._postion = position;
    }

    @Override
    public void onClick(View v) {
        // on selecting grid view image
        // launch full screen activity
        Intent i = new Intent(_activity, FullScreenViewActivity.class);
        i.putExtra("position", _postion);
        _activity.startActivity(i);
    }

}

/*
 * Resizing image size
 */
public static Bitmap decodeFile(String filePath, int WIDTH, int HIGHT) {
    try {

        File f = new File(filePath);

        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(new FileInputStream(f), null, o);

        final int REQUIRED_WIDTH = WIDTH;
        final int REQUIRED_HIGHT = HIGHT;
        int scale = 1;
        while (o.outWidth / scale / 2 >= REQUIRED_WIDTH
                && o.outHeight / scale / 2 >= REQUIRED_HIGHT)
            scale *= 2;

        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize = scale;
        return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
    return null;
}

}

pojo class AppConstant 

public class AppConstant {

// Number of columns of Grid View
public static final int NUM_OF_COLUMNS = 3;

// Gridview image padding
public static final int GRID_PADDING = 8; // in dp

// SD card image directory
//@SuppressLint("SdCardPath")
public static final String PHOTO_ALBUM = "/SD card/kul_pics/";

// supported file formats
public static final List<String> FILE_EXTN = Arrays.asList("jpg", "jpeg",
        "png");
}

ImageView类TouchImageView.java 

public class TouchImageView extends ImageView {

Matrix matrix;

// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;

// Remember some things for zooming
PointF last = new PointF();
PointF start = new PointF();
float minScale = 1f;
float maxScale = 3f;
float[] m;

int viewWidth, viewHeight;
static final int CLICK = 3;
float saveScale = 1f;
protected float origWidth, origHeight;
int oldMeasuredWidth, oldMeasuredHeight;

ScaleGestureDetector mScaleDetector;

Context context;

public TouchImageView(Context context) {
    super(context);
    sharedConstructing(context);
}

public TouchImageView(Context context, AttributeSet attrs) {
    super(context, attrs);
    sharedConstructing(context);
}

private void sharedConstructing(Context context) {
    super.setClickable(true);
    this.context = context;
    mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
    matrix = new Matrix();
    m = new float[9];
    setImageMatrix(matrix);
    setScaleType(ScaleType.MATRIX);

    setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            mScaleDetector.onTouchEvent(event);
            final CheckBox cb=new CheckBox(getContext());
            PointF curr = new PointF(event.getX(), event.getY());

            switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                last.set(curr);
                start.set(last);
                cb.setChecked(false);
                mode = DRAG;
                break;

            case MotionEvent.ACTION_MOVE:
                if (mode == DRAG) {
                    float deltaX = curr.x - last.x;
                    float deltaY = curr.y - last.y;
                    float fixTransX = getFixDragTrans(deltaX, viewWidth,
                            origWidth * saveScale);
                    float fixTransY = getFixDragTrans(deltaY, viewHeight,
                            origHeight * saveScale);
                    matrix.postTranslate(fixTransX, fixTransY);
                    fixTrans();
                    cb.setChecked(false);
                    last.set(curr.x, curr.y);
                }
                break;

            case MotionEvent.ACTION_UP:
                mode = NONE;
                int xDiff = (int) Math.abs(curr.x - start.x);
                int yDiff = (int) Math.abs(curr.y - start.y);
                if (xDiff < CLICK && yDiff < CLICK)
                    cb.setChecked(false);
                    performClick();
                break;

            case MotionEvent.ACTION_POINTER_UP:
                mode = NONE;
                break;
            }

            setImageMatrix(matrix);
            invalidate();
            return true; // indicate event was handled
        }

    });
}

public void setMaxZoom(float x) {
    maxScale = x;
}

private class ScaleListener extends
        ScaleGestureDetector.SimpleOnScaleGestureListener {
    @Override
    public boolean onScaleBegin(ScaleGestureDetector detector) {
        mode = ZOOM;
        return true;
    }

    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        float mScaleFactor = detector.getScaleFactor();
        float origScale = saveScale;
        saveScale *= mScaleFactor;
        if (saveScale > maxScale) {
            saveScale = maxScale;
            mScaleFactor = maxScale / origScale;
        } else if (saveScale < minScale) {
            saveScale = minScale;
            mScaleFactor = minScale / origScale;
        }

        if (origWidth * saveScale <= viewWidth
                || origHeight * saveScale <= viewHeight)
            matrix.postScale(mScaleFactor, mScaleFactor, viewWidth / 2,
                    viewHeight / 2);
        else
            matrix.postScale(mScaleFactor, mScaleFactor,
                    detector.getFocusX(), detector.getFocusY());

        fixTrans();
        return true;
    }
}

void fixTrans() {
    matrix.getValues(m);
    float transX = m[Matrix.MTRANS_X];
    float transY = m[Matrix.MTRANS_Y];

    float fixTransX = getFixTrans(transX, viewWidth, origWidth * saveScale);
    float fixTransY = getFixTrans(transY, viewHeight, origHeight
            * saveScale);

    if (fixTransX != 0 || fixTransY != 0)
        matrix.postTranslate(fixTransX, fixTransY);
}

float getFixTrans(float trans, float viewSize, float contentSize) {
    float minTrans, maxTrans;

    if (contentSize <= viewSize) {
        minTrans = 0;
        maxTrans = viewSize - contentSize;
    } else {
        minTrans = viewSize - contentSize;
        maxTrans = 0;
    }

    if (trans < minTrans)
        return -trans + minTrans;
    if (trans > maxTrans)
        return -trans + maxTrans;
    return 0;
}

float getFixDragTrans(float delta, float viewSize, float contentSize) {
    if (contentSize <= viewSize) {
        return 0;
    }
    return delta;
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    viewWidth = MeasureSpec.getSize(widthMeasureSpec);
    viewHeight = MeasureSpec.getSize(heightMeasureSpec);

    //
    // Rescales image on rotation
    //
    if (oldMeasuredHeight == viewWidth && oldMeasuredHeight == viewHeight
            || viewWidth == 0 || viewHeight == 0)
        return;
    oldMeasuredHeight = viewHeight;
    oldMeasuredWidth = viewWidth;

    if (saveScale == 1) {
        // Fit to screen.
        float scale;

        Drawable drawable = getDrawable();
        if (drawable == null || drawable.getIntrinsicWidth() == 0
                || drawable.getIntrinsicHeight() == 0)
            return;
        int bmWidth = drawable.getIntrinsicWidth();
        int bmHeight = drawable.getIntrinsicHeight();

        Log.d("bmSize", "bmWidth: " + bmWidth + " bmHeight : " + bmHeight);

        float scaleX = (float) viewWidth / (float) bmWidth;
        float scaleY = (float) viewHeight / (float) bmHeight;
        scale = Math.min(scaleX, scaleY);
        matrix.setScale(scale, scale);

        // Center the image
        float redundantYSpace = (float) viewHeight
                - (scale * (float) bmHeight);
        float redundantXSpace = (float) viewWidth
                - (scale * (float) bmWidth);
        redundantYSpace /= (float) 2;
        redundantXSpace /= (float) 2;

        matrix.postTranslate(redundantXSpace, redundantYSpace);

        origWidth = viewWidth - 2 * redundantXSpace;
        origHeight = viewHeight - 2 * redundantYSpace;
        setImageMatrix(matrix);
    }
    fixTrans();
}

pojo类Utils.java 

public class Utils {

private Context _context;
static String filePath="";

// constructor
public Utils(Context context) {
    this._context = context;
}

/*
 * Reading file paths from SDCard
 */
public ArrayList<String> getFilePaths() {
    ArrayList<String> filePaths = new ArrayList<String>();

    File directory = new File(
            Environment.getExternalStorageDirectory(),"myphoto");
                    //+ File.separator + AppConstant.PHOTO_ALBUM);

    // check for directory
    if (directory.isDirectory()) {
        // getting list of file paths
        File[] listFiles = directory.listFiles();

        // Check for count
        if (listFiles.length > 0) {

            // loop through all files
            for (int i = 0; i < listFiles.length; i++) {

                // get file path
                 filePath = listFiles[i].getAbsolutePath();

                // check for supported file extension
                if (IsSupportedFile(filePath)) {
                    // Add image path to array list
                    filePaths.add(filePath);
                }

            }
        } else {
            // image directory is empty
            Toast.makeText(
                    _context,
                    AppConstant.PHOTO_ALBUM
                            + " is empty. Please load some images in it !",
                    Toast.LENGTH_LONG).show();
        }

    } else {
        AlertDialog.Builder alert = new AlertDialog.Builder(_context);
        alert.setTitle("Error!");
        alert.setMessage(AppConstant.PHOTO_ALBUM
                + " directory path is not valid! Please set the image directory name AppConstant.java class");
        alert.setPositiveButton("OK", null);
        alert.show();
    }

    return filePaths;
}

/*
 * Check supported file extensions
 * 
 * @returns boolean
 */
private boolean IsSupportedFile(String filePath) {
    String ext = filePath.substring((filePath.lastIndexOf(".") + 1),
            filePath.length());

    if (AppConstant.FILE_EXTN
            .contains(ext.toLowerCase(Locale.getDefault())))
        return true;
    else
        return false;

}

/*
 * getting screen width
 */
public int getScreenWidth() {
    int columnWidth;
    WindowManager wm = (WindowManager) _context
            .getSystemService(Context.WINDOW_SERVICE);
    Display display = wm.getDefaultDisplay();

    final Point point = new Point();
    try {
        display.getSize(point);
    } catch (java.lang.NoSuchMethodError ignore) { // Older device
        point.x = display.getWidth();
        point.y = display.getHeight();
    }
    columnWidth = point.x;
    return columnWidth;
}
public String getFileName() throws IOException{
    getFilePaths();
    File directory = new File(
            Environment.getExternalStorageDirectory(),"myphoto");
    if (directory.isDirectory()) {
        // getting list of file paths
        File[] listFiles = directory.listFiles();
    // loop through all files
        if (listFiles.length > 0) {
    for (int i = 0; i < listFiles.length; i++) {

        // get file path
         filePath = listFiles[i].getCanonicalPath();//getAbsolutePath();
    }
        }
    }
    return filePath;
}
}

在我的FullScreenViewActivity类中，我希望获得图像文件的名称，但每次显示相同的图像名称，即使在滑动图像后也是如此。

1 个答案:

答案 0 :(得分：0)

在 layout_fullscreen_image.xml 中添加TextView，并将其ID设为 filename_textView

更新 FullScreenImageAdapter.java 

@Override
public Object instantiateItem(ViewGroup container, int position) {
TouchImageView imgDisplay;
TextView fileNameTextView;
Button btnClose;

inflater = (LayoutInflater) _activity
        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View viewLayout = inflater.inflate(R.layout.layout_fullscreen_image, container,
        false);

imgDisplay = (TouchImageView) viewLayout.findViewById(R.id.imgDisplay);
fileNameTextView=viewLayout.findViewById(R.id.filename_textView);
File newFile=new File(_imagePaths.get(position));
String fileName=newFile.getName();//contains file name
fileNameTextView.setText(fileName);
 btnClose = (Button) viewLayout.findViewById(R.id.btnClose);

BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap bitmap = BitmapFactory.decodeFile(_imagePaths.get(position), options);
imgDisplay.setImageBitmap(bitmap);
btnClose.setOnClickListener(new OnClickListener()
        {

            @Override
            public void onClick(View v)
            {
                // TODO Auto-generated method stub
                Toast.makeText(c, fileName, Toast.LENGTH_LONG).show();
            }
        });
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