嗨，我正在 Android 中开发应用程序。我正在使用 Coverflow 视图来显示图像。但问题是它显示在屏幕中央。我需要显示在屏幕顶部。请帮助我，我是新手安卓。
代码：我的活动课
public class NewspaperCoverFlowActivity extends Activity
{
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
Coverflow coverFlow;
coverFlow = new Coverflow(this);
coverFlow.setAdapter(new ImageAdapter(this));
ImageAdapter coverImageAdapter = new ImageAdapter(this);
coverFlow.setAdapter(coverImageAdapter);
coverFlow.setSpacing(2);
coverFlow.setSelection(1, true);
coverFlow.setAnimationDuration(1500);
setContentView(coverFlow);
}
}
Adapter Class:
public class ImageAdapter extends BaseAdapter
{
int mGalleryItemBackground;
private Context mContext;
static final String URL="XXXXXXXXXXX";
String[] imageurl ;
private FileInputStream fis;
private Integer[] mImageIds =
{
R.drawable.ic_launcher,
R.drawable.ic_launcher,
R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher
};
private ImageView[] mImages;
public ImageAdapter(Context c)
{
// System.out.println("Inside image cons");
mContext = c;
getelement();
createReflectedImages();
// mImages = new ImageView[imageurl.length];
}
public void getelement()
{
// System.out.println("Inside getelement");
// String[] itemsarray={};
// ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>();
// ArrayList<String> menuItems = new ArrayList<String>();
TaplistingParser parser = new TaplistingParser();
String xml= parser.getXmlFromUrl(URL);
Document doc=parser.getDomElement(xml);
// System.out.println("sssss="+doc);
NodeList nl=doc.getElementsByTagName("article");
imageurl = new String[nl.getLength()];
mImages = new ImageView[imageurl.length];
// System.out.println("len="+nl.getLength());
for(int i=0; i < nl.getLength(); i++ )
{
// System.out.println("Inside for");
// HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element) nl.item(i);
// map.put("SectionName", parser.getValue(e, "sectionname"));
// System.out.println("b4 items="+parser.getValue(e, "sectionname"));
// itemsarray[i] = parser.getValue(e, "sectionname");
// System.out.println("items="+itemsarray[i]);
imageurl[i]=parser.getValue(e, "kickerimage");
// System.out.println("i am here..."+imageurl[i]);
// menuItems.add(parser.getValue(e, "sectionname"));
// menuItems.add(parser.getValue(e, "sectionname"));
// System.out.println("menu="+menuItems);
}
// String[] itemsarray = menuItems.toArray(new String[menuItems.size()]);
// String[] itemsarray = new String[menuItems.size()];
// itemsarray=menuItems.toArray(itemsarray);
//// for(int j= 0;j < itemsarray.length;j++ )
//// {
//// Log.d("string is",(itemsarray[j]));
//// }
// return itemsarray;
}
public boolean createReflectedImages() {
//The gap we want between the reflection and the original image
final int reflectionGap = 4;
int index = 0;
// for (int imageId : imageurl)
for(int i=0;i<imageurl.length;i++)
{
// System.out.println("image="+imageurl[i]);
// Bitmap originalImage = BitmapFactory.decodeResource(getResources(),
// imageurl[i]);
Bitmap originalImage = DownloadImage(imageurl[i]);
int width = originalImage.getWidth();
int height = originalImage.getHeight();
//This will not scale but will flip on the Y axis
Matrix matrix = new Matrix();
matrix.preScale(1, -1);
//Create a Bitmap with the flip matrix applied to it.
//We only want the bottom half of the image
Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0, height/2, width, height/2, matrix, false);
//Create a new bitmap with same width but taller to fit reflection
Bitmap bitmapWithReflection = Bitmap.createBitmap(width
, (height + height/2), Config.ARGB_8888);
//Create a new Canvas with the bitmap that's big enough for
//the image plus gap plus reflection
Canvas canvas = new Canvas(bitmapWithReflection);
//Draw in the original image
canvas.drawBitmap(originalImage, 0, 0, null);
//Draw in the gap
Paint deafaultPaint = new Paint();
canvas.drawRect(0, height, width, height + reflectionGap, deafaultPaint);
//Draw in the reflection
canvas.drawBitmap(reflectionImage,0, height + reflectionGap, null);
//Create a shader that is a linear gradient that covers the reflection
Paint paint = new Paint();
LinearGradient shader = new LinearGradient(0, originalImage.getHeight(), 0,
bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff, 0x00ffffff,
TileMode.CLAMP);
//Set the paint to use this shader (linear gradient)
paint.setShader(shader);
//Set the Transfer mode to be porter duff and destination in
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
//Draw a rectangle using the paint with our linear gradient
canvas.drawRect(0, height, width,
bitmapWithReflection.getHeight() + reflectionGap, paint);
ImageView imageView = new ImageView(mContext);
imageView.setImageBitmap(bitmapWithReflection);
imageView.setLayoutParams(new Coverflow.LayoutParams(120,180));
imageView.setScaleType(ScaleType.MATRIX);
mImages[index++] = imageView;
}
return true;
}
@Override
public int getCount()
{
// TODO Auto-generated method stub
return imageurl.length;
}
@Override
public Object getItem(int position)
{
// TODO Auto-generated method stub
return imageurl[position];
}
@Override
public long getItemId(int position)
{
// TODO Auto-generated method stub
return position;
}
public View getView(int position, View convertView, ViewGroup parent)
{
//Use this code if you want to load from resources
// DownloadImage(imageurl[position]);
Bitmap bit = DownloadImage(imageurl[position]);
ImageView i = new ImageView(mContext);
i.setImageBitmap(bit);
// i.setImageResource(imageurl[position]);
i.setLayoutParams(new Coverflow.LayoutParams(170, 170));
i.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
//Make sure we set anti-aliasing otherwise we get jaggies
BitmapDrawable drawable = (BitmapDrawable) i.getDrawable();
drawable.setAntiAlias(true);
return i;
//return mImages[position];
}
/** 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)));
}
Bitmap bitmap = null;
private Bitmap DownloadImage(String URL)
{
// System.out.println("image inside="+URL);
InputStream in = null;
try
{
in = OpenHttpConnection(URL);
bitmap = BitmapFactory.decodeStream(in);
in.close();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// System.out.println("image last");
return bitmap;
}
private InputStream OpenHttpConnection(String urlString)
throws IOException
{
InputStream in = null;
int response = -1;
URL url = new URL(urlString);
URLConnection conn = url.openConnection();
if (!(conn instanceof HttpURLConnection))
throw new IOException("Not an HTTP connection");
try{
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setAllowUserInteraction(false);
httpConn.setInstanceFollowRedirects(true);
httpConn.setRequestMethod("GET");
httpConn.connect();
response = httpConn.getResponseCode();
if (response == HttpURLConnection.HTTP_OK)
{
in = httpConn.getInputStream();
}
}
catch (Exception ex)
{
throw new IOException("Error connecting");
}
return in;
}
}
覆盖流类：
public class Coverflow extends Gallery
{
private Camera mCamera = new Camera();
private int mMaxRotationAngle = 60;
private int mMaxZoom = -120;
private int mCoveflowCenter;
public Coverflow(Context context) {
super(context);
this.setStaticTransformationsEnabled(true);
}
public Coverflow(Context context, AttributeSet attrs) {
super(context, attrs);
this.setStaticTransformationsEnabled(true);
}
public Coverflow(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
this.setStaticTransformationsEnabled(true);
}
public int getMaxRotationAngle() {
return mMaxRotationAngle;
}
public void setMaxRotationAngle(int maxRotationAngle) {
mMaxRotationAngle = maxRotationAngle;
}
public int getMaxZoom() {
return mMaxZoom;
}
public void setMaxZoom(int maxZoom) {
mMaxZoom = maxZoom;
}
private int getCenterOfCoverflow() {
return (getWidth() - getPaddingLeft() - getPaddingRight()) / 2 + getPaddingLeft();
}
private static int getCenterOfView(View view) {
return view.getLeft() + view.getWidth() / 2;
}
protected boolean getChildStaticTransformation(View child, Transformation t) {
final int childCenter = getCenterOfView(child);
final int childWidth = child.getWidth() ;
int rotationAngle = 0;
t.clear();
t.setTransformationType(Transformation.TYPE_MATRIX);
if (childCenter == mCoveflowCenter) {
transformImageBitmap((ImageView) child, t, 0);
} else {
rotationAngle = (int) (((float) (mCoveflowCenter - childCenter)/ childWidth) * mMaxRotationAngle);
if (Math.abs(rotationAngle) > mMaxRotationAngle) {
rotationAngle = (rotationAngle < 0) ? -mMaxRotationAngle : mMaxRotationAngle;
}
transformImageBitmap((ImageView) child, t, rotationAngle);
}
return true;
}
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
mCoveflowCenter = getCenterOfCoverflow();
super.onSizeChanged(w, h, oldw, oldh);
}
private void transformImageBitmap(ImageView child, Transformation t, int rotationAngle) {
mCamera.save();
final Matrix imageMatrix = t.getMatrix();;
final int imageHeight = child.getLayoutParams().height;;
final int imageWidth = child.getLayoutParams().width;
final int rotation = Math.abs(rotationAngle);
mCamera.translate(0.0f, 0.0f, 100.0f);
//As the angle of the view gets less, zoom in
if ( rotation < mMaxRotationAngle ) {
float zoomAmount = (float) (mMaxZoom + (rotation * 1.5));
mCamera.translate(0.0f, 0.0f, zoomAmount);
}
mCamera.rotateY(rotationAngle);
mCamera.getMatrix(imageMatrix);
imageMatrix.preTranslate(-(imageWidth/2), -(imageHeight/2));
imageMatrix.postTranslate((imageWidth/2), (imageHeight/2));
mCamera.restore();
}
}