您好我正在使用图库小部件来显示从 Internet 下载的图像。
显示几张图像，我希望在人们在屏幕上上下滑动时进行逐渐缩放。我知道如何实现触摸事件唯一我不知道如何使整个画廊视图逐渐增长。我不想放大一张图像我希望整个画廊逐渐放大/缩小。
EDIT3：我设法缩放画廊的可见部分，但问题是我需要找到一种方法让画廊了解它并更新它的其他孩子。
发生的情况是，如果 3 个图像可见，然后您开始缩放并且图库确实变小了，图像也是如此，但在这种情况下我想要更多图像可见，但我不知道如何达到所需的效果。这是整个代码：
public class Gallery1 extends Activity implements OnTouchListener {
private static final String TAG = "GalleryTest";
private float zoom=0.0f;
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
Gallery g;
LinearLayout layout2;
private ImageAdapter ad;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.gallery_1);
layout2=(LinearLayout) findViewById(R.id.layout2);
// Reference the Gallery view
g = (Gallery) findViewById(R.id.gallery);
// Set the adapter to our custom adapter (below)
ad=new ImageAdapter(this);
g.setAdapter(ad);
layout2.setOnTouchListener(this);
}
public void zoomList(boolean increase) {
Log.i(TAG, "startig animation");
AnimatorSet set = new AnimatorSet();
set.playTogether(
ObjectAnimator.ofFloat(g, "scaleX", zoom),
ObjectAnimator.ofFloat(g, "scaleY", zoom)
);
set.addListener(new AnimatorListener() {
@Override
public void onAnimationStart(Animator animation) {
}
@Override
public void onAnimationRepeat(Animator animation) {
// TODO Auto-generated method stub
}
@Override
public void onAnimationEnd(Animator animation) {
}
@Override
public void onAnimationCancel(Animator animation) {
// TODO Auto-generated method stub
}
});
set.setDuration(100).start();
}
public class ImageAdapter extends BaseAdapter {
private static final int ITEM_WIDTH = 136;
private static final int ITEM_HEIGHT = 88;
private final int mGalleryItemBackground;
private final Context mContext;
private final Integer[] mImageIds = {
R.drawable.gallery_photo_1,
R.drawable.gallery_photo_2,
R.drawable.gallery_photo_3,
R.drawable.gallery_photo_4,
R.drawable.gallery_photo_5,
R.drawable.gallery_photo_6,
R.drawable.gallery_photo_7,
R.drawable.gallery_photo_8
};
private final float mDensity;
public ImageAdapter(Context c) {
mContext = c;
// See res/values/attrs.xml for the <declare-styleable> that defines
// Gallery1.
TypedArray a = obtainStyledAttributes(R.styleable.Gallery1);
mGalleryItemBackground = a.getResourceId(
R.styleable.Gallery1_android_galleryItemBackground, 1);
a.recycle();
mDensity = c.getResources().getDisplayMetrics().density;
}
public int getCount() {
return mImageIds.length;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) {
convertView = new ImageView(mContext);
imageView = (ImageView) convertView;
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
imageView.setLayoutParams(new Gallery.LayoutParams(
(int) (ITEM_WIDTH * mDensity + 0.5f),
(int) (ITEM_HEIGHT * mDensity + 0.5f)));
} else {
imageView = (ImageView) convertView;
}
imageView.setImageResource(mImageIds[position]);
return imageView;
}
}
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_MOVE
&& event.getPointerCount() > 1) {
midPoint(mid, event);
if(mid.y > start.y){
Log.i(TAG, "Going down (Math.abs(mid.y - start.y)= "+(Math.abs(mid.y - start.y))+" and zoom="+zoom); // going down so increase
if ((Math.abs(mid.y - start.y) > 10) && (zoom<2.5f)){
zoom=zoom+0.1f;
midPoint(start, event);
zoomList(true);
}
return true;
}else if(mid.y < start.y){
Log.i(TAG, "Going up (Math.abs(mid.y - start.y)= "+(Math.abs(mid.y - start.y))+" and zoom="+zoom); //smaller
if ((Math.abs(mid.y - start.y) > 10) &&(zoom>0.1)){
midPoint(start, event);
zoom=zoom-0.1f;
zoomList(false);
}
return true;
}
}
else if (event.getAction() == MotionEvent.ACTION_POINTER_DOWN) {
Log.e(TAG, "Pointer went down: " + event.getPointerCount());
return true;
}
else if (event.getAction() == MotionEvent.ACTION_UP) {
Log.i(TAG, "Pointer going up");
return true;
}
else if (event.getAction() == MotionEvent.ACTION_DOWN) {
Log.i(TAG, "Pointer going down");
start.set(event.getX(), event.getY());
return true;
}
return false;
// indicate event was handled or not
}
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);
}
我意识到我可能不得不扩展 Gallery 甚至另一个 View 组或创建我自己的类，但我不知道从哪里开始：哪种方法使用负责缩放的方法......
EDIT4：我不知道他的问题是否足够清楚。以下是状态示例：
状态一：初始状态，我们有 3 张图像在视图中
状态 2：我们检测到 2 个手指向上的垂直触摸 = 我们必须缩小
状态3：我们开始缩放=在画廊或孩子上的动画？？？
状态 4：画廊检测到它的 3 个孩子更小
状态 5：画廊根据新的可用空间添加 1 个/多个孩子
最后更新：感谢所有发布的内容，但我终于得出了一个结论，那就是根本不使用 Gallery：1. 它已被弃用 2. 对于我的情况，它的可定制性不够
如果您想一次为多个图像设置动画，您可能需要考虑使用 OpenGl，我正在使用 libgdx 库： https ://github.com/libgdx/libgdx