Android编程滑动效果之Gallery+GridView实现图片预览功能(附demo源码下载)
本文实例讲述了Android编程滑动效果之Gallery+GridView实现图片预览功能。分享给大家供大家参考,具体如下:
Android系统自带一个GridView和Gallery两个控件,GridView网格显示,Gallery单个浏览,两者结合起来可以真正实现Gallery浏览图片效果。
本示例通过GridView和Gallery两个控件,模仿实现一个完整的仿Gallery图像集的图片浏览效果。效果图如下:
1、GridView
首先,自定义一个GridImageAdapter图片适配器,用于填充GridView控件的图片
public class GridImageAdapter extends BaseAdapter { private Context mContext; Drawable btnDrawable; public GridImageAdapter(Context context) { mContext = context; Resources resources = context.getResources(); btnDrawable = resources.getDrawable(R.drawable.bg); } @Override public int getCount() { return ImageSource.mThumbIds.length; } @Override public Object getItem(int position) { return position; } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { ImageViewExt imageView; int space; if (convertView == null) { imageView = new ImageViewExt(mContext); if (imageCol == 5) { space = dm.heightPixels / imageCol - 6; imageView.setLayoutParams(new GridView.LayoutParams(space, space)); } else { space = dm.widthPixels / imageCol - 6; imageView.setLayoutParams(new GridView.LayoutParams( space, space)); } imageView.setAdjustViewBounds(true); imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); // 缩放图片使其长和宽一样 imageView.setPadding(3, 3, 3, 3); } else { imageView = (ImageViewExt) convertView; } imageView.setImageResource(ImageSource.mThumbIds[position]); return imageView; } }
然后,用GridImageAdapter填充GridView
gridView = (GridView) findViewById(R.id.myGrid); gridImageAdapter = new GridImageAdapter(this); gridView.setAdapter(gridImageAdapter); gridView.setOnItemClickListener(listener); // 设置点击监听事件
最后,设置GridView控件的点击监听事件
AdapterView.OnItemClickListener listener = new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> arg0, View arg1, int position, long id) { Intent intent = new Intent(); intent.setClass(GridViewActivity.this, GalleryActivity.class); intent.putExtra("position", position); startActivity(intent); } };
2、Gallery
完成了GridView的图片显示、监听事件后,现在点击图片,会启动一个Activity来显示当前点击的图片,此时显示图片的控件便是Gallery
首先,同GridView一样,自定义一个ImageAdapter图片适配器,用来填充Gallery
public class ImageAdapter extends BaseAdapter { private Context mContext; private int mPos; public ImageAdapter(Context context) { mContext = context; } public void setOwnposition(int ownposition) { this.mPos = ownposition; } public int getOwnposition() { return mPos; } @Override public int getCount() { return ImageSource.mThumbIds.length; } @Override public Object getItem(int position) { mPos=position; return position; } @Override public long getItemId(int position) { mPos=position; return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { mPos=position; ImageView imageview = new ImageView(mContext); imageview.setBackgroundColor(0xFF000000); imageview.setScaleType(ImageView.ScaleType.FIT_CENTER); imageview.setLayoutParams(new myGallery.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)); imageview.setImageResource(ImageSource.mThumbIds[position]); return imageview; } }
然后,用ImageAdapter填充Gallery
myGallery galllery = (myGallery) findViewById(R.id.mygallery); Intent intent = getIntent(); position = intent.getIntExtra("position", 0); // 获取GridViewActivity传来的图片位置position ImageAdapter imgAdapter=new ImageAdapter(this); galllery.setAdapter(imgAdapter); // 设置图片ImageAdapter galllery.setSelection(position); // 设置当前显示图片 Animation an= AnimationUtils.loadAnimation(this,R.anim.scale ); // Gallery动画 galllery.setAnimation(an);
此时,如果细心可以注意到,我们的Gallery也是自己定义的myGallery,具体定义如下:
public class myGallery extends Gallery { boolean isFirst = false; boolean isLast = false; public myGallery(Context context) { super(context); } public myGallery(Context context, AttributeSet paramAttributeSet) { super(context, paramAttributeSet); } /** 是否向左滑动(true - 向左滑动; false - 向右滑动) */ private boolean isScrollingLeft(MotionEvent e1, MotionEvent e2) { return e2.getX() > e1.getX(); } @Override public boolean onFling(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { ImageAdapter ia = (ImageAdapter) this.getAdapter(); int p = ia.getOwnposition(); // 获取当前图片的position int count = ia.getCount(); // 获取全部图片的总数count int kEvent; if (isScrollingLeft(e1, e2)) { if (p == 0 && isFirst) { Toast.makeText(this.getContext(), "已是第一页", Toast.LENGTH_SHORT).show(); } else if (p == 0) { isFirst = true; } else { isLast = false; } kEvent = KeyEvent.KEYCODE_DPAD_LEFT; } else { if (p == count - 1 && isLast) { Toast.makeText(this.getContext(), "已到最后一页", Toast.LENGTH_SHORT).show(); } else if (p == count - 1) { isLast = true; } else { isFirst = false; } kEvent = KeyEvent.KEYCODE_DPAD_RIGHT; } onKeyDown(kEvent, null); return true; } }
GalleryActivity的布局文件gallery.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="center" android:orientation="horizontal" android:padding="10dip" > <RelativeLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:background="#000000" android:padding="2dip" > <com.homer.gridgallery.myGallery android:id="@+id/mygallery" android:layout_width="fill_parent" android:layout_height="fill_parent" android:spacing="16dp" /> </RelativeLayout> </LinearLayout>
完整实例代码点击此处本站下载。
更多关于Android相关内容感兴趣的读者可查看本站专题:《Android开发动画技巧汇总》、《Android开发入门与进阶教程》及《Android控件用法总结》。
希望本文所述对大家Android程序设计有所帮助。
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