我想知道如何获得对画廊视图当前显示的图像的引用？例如，我想添加一个按钮来旋转图像，但我不明白如何选择它。我认为这是可能的，getItemViewType但我不明白它会返回什么。
活动
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.image_show);
app = this;
final Gallery gallery = (Gallery) findViewById(R.id.gallery);
// EDGES ARE INVISIBLE
gallery.setHorizontalFadingEdgeEnabled(false);
ia = new ImageAdapterr(this);
gallery.setAdapter(ia);
// ia.getView(position, convertView, parent);
final int length = UILApplication.photo_buffer_big.size();
Button back_btn = (Button) findViewById(R.id.analitics_back_btn);
back_btn.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
finish();
}
});
final TextView img_counter_tv = (TextView) findViewById(R.id.img_counter);
img_counter_tv.setText(p + 1 + "/" + length);
Button nextButton = (Button) findViewById(R.id.next_btn);
nextButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if (p < length - 1) {
p++;
} else {
p = 0;
}
gallery.setSelection(p, true);
img_counter_tv.setText(p + 1 + "/" + length);
}
});
Button backButton = (Button) findViewById(R.id.back_btn);
backButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if (p == 0) {
p = length - 1;
} else {
p--;
}
gallery.setSelection(p, true);
img_counter_tv.setText(p + 1 + "/" + length);
}
});
}
public void rotateS(View v) {
// int q = (ia.getItemViewType(p));
// Bitmap b = ((BitmapDrawable) imView.getDrawable()).getBitmap();
Bitmap b = ((BitmapDrawable) images.get(p).getDrawable()).getBitmap();
Matrix matrix = new Matrix();
matrix.postRotate(geg);
matrix.postScale(0.5f, 0.5f);
Bitmap bMapRotate = Bitmap.createBitmap(b, 0, 0, b.getWidth(), b.getHeight(), matrix, true);
imView.setImageBitmap(bMapRotate);
geg = (geg+90)%360;
}
适配器
class ImageAdapterr extends BaseAdapter {
/** The parent context */
private Context myContext;
/** Simple Constructor saving the 'parent' context. */
public ImageAdapterr(Context c) {
this.myContext = c;
}
/** Returns the amount of images we have defined. */
public int getCount() {
return UILApplication.photo_buffer_big.size();
}
/* Use the array-Positions as unique IDs */
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
/**
* Returns a new ImageView to be displayed, depending on the position
* passed.
*/
// public ImageView getImage(int position, View convertView, ViewGroup parent) {
//
// }
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imView = new ImageView(this.myContext);
imgPos = position;
AsyncLoad imLoad = new AsyncLoad();
imLoad.execute();
try {
bm = imLoad.get();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (bm != null) {
imView.setImageBitmap(bm);
} else if (bm == null) {
imView.setImageResource(R.drawable.logo);
}
/* Image should be scaled as width/height are set. */
// imView.setScaleType(ImageView.ScaleType.FIT_CENTER);
/* Set the Width/Height of the ImageView. */
imView.setLayoutParams(new Gallery.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.MATCH_PARENT));
imView.setOnTouchListener(new OnTouchListener() {
private static final String TAG = "Touch";
// These matrices will be used to move and zoom image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
PointF start = new PointF();
public PointF mid = new PointF();
// We can be in one of these 3 states
public static final int NONE = 0;
public static final int DRAG = 1;
public static final int ZOOM = 2;
public int mode = NONE;
float oldDist;
public boolean onTouch(View v, MotionEvent event) {
ImageView view = (ImageView) v;
view.setScaleType(ImageView.ScaleType.MATRIX);
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
Log.d(TAG, "mode=DRAG");
mode = DRAG;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
Log.d(TAG, "oldDist=" + oldDist);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
Log.d(TAG, "mode=ZOOM");
}
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x,
event.getY() - start.y);
} else if (mode == ZOOM) {
float newDist = spacing(event);
Log.d(TAG, "newDist=" + newDist);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
Log.d(TAG, "mode=NONE");
break;
}
// Perform the transformation
view.setImageMatrix(matrix);
return true; // indicate event was handled
}
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}
private void midPoint(PointF point, MotionEvent event) {
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x / 2, y / 2);
}
});
images.add(imView);
Log.d("images","id "+ imView.getId());
Log.d("images","size "+ images.size());
return imView;
}
/**
* Returns the size (0.0f to 1.0f) of the views depending on the
* 'offset' to the center.
*/
public float getScale(boolean focused, int offset) {
/* Formula: 1 / (2 ^ offset) */
return Math.max(0, 1.0f / (float) Math.pow(2, Math.abs(offset)));
}
class AsyncLoad extends AsyncTask<Void, Void, Bitmap> {
ProgressDialog pd;
@Override
protected void onPreExecute() {
pd = new ProgressDialog(app);
pd.setOwnerActivity(app);
pd.setTitle("Идет загрузка...");
pd.setCancelable(true);
pd.show();
}
@Override
protected Bitmap doInBackground(Void... arg0) {
// TODO Auto-generated method stub
try {
/*
* Open a new URL and get the InputStream to load data from it.
*/
URL aURL = new URL(UILApplication.photo_buffer_big.get(imgPos));
URLConnection conn = aURL.openConnection();
conn.connect();
InputStream is = conn.getInputStream();
/* Buffered is always good for a performance plus. */
BufferedInputStream bis = new BufferedInputStream(is);
/* Decode url-data to a bitmap. */
bm = BitmapFactory.decodeStream(bis);
bis.close();
is.close();
/* Apply the Bitmap to the ImageView that will be returned. */
// imView.setImageBitmap(bm);
} catch (IOException e) {
// imView.setImageResource(R.drawable.logo);
bm = null;
Log.e("DEBUGTAG", "Remote Image Exception", e);
}
return bm;
}
@Override
protected void onPostExecute(Bitmap arg0) {
pd.dismiss();
}
}
}