Android书架实现

转自http://blog.csdn.net/wangkuifeng0118/article/details/7944215

书架效果：

　　下面先看一下书架的实现原理吧！

　　首先看一下layout下的布局文件main.xml

 <?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:orientation="vertical"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
 >
 <include layout="@layout/head" android:id="@+id/head"/>

     <cn.com.karl.view.MyGridView
         android:id="@+id/bookShelf"
         android:layout_width="fill_parent"
         android:layout_height="fill_parent"
         android:layout_below="@id/head"
         android:cacheColorHint="#00000000"
         android:columnWidth="90.0dip"
         android:fadingEdge="none"
         android:horizontalSpacing="5dp"
         android:listSelector="#00000000"
         android:numColumns="3"
         android:scrollbars="none"
         android:verticalSpacing="20dp" />

    <SlidingDrawer
         android:id="@+id/sliding"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:content="@+id/allApps"
         android:handle="@+id/imageViewIcon"
         android:orientation="vertical" >  

         <Button
             android:id="@+id/imageViewIcon"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="本地"
             android:textSize="18dp"
             android:background="@drawable/btn_local" /> 

         <GridView
             android:id="@+id/allApps"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:background="@drawable/file_list_bg"
             android:columnWidth="60dp"
             android:gravity="center"
             android:horizontalSpacing="10dp"
             android:numColumns="auto_fit"
             android:padding="10dp"
             android:stretchMode="columnWidth"
             android:verticalSpacing="10dp" />  

     </SlidingDrawer>  

 </RelativeLayout>

　　上面是个自定义的gridview主要来实现书架，因为每一本书是一个item，在自定义的gridview中计算每一行的高度，然后把书架画上去。下面是个抽屉。

 public class MyGridView extends GridView {

     private Bitmap background;

     public MyGridView(Context context, AttributeSet attrs) {
         super(context, attrs);
         background = BitmapFactory.decodeResource(getResources(),
                 R.drawable.bookshelf_layer_center);
     }

     @Override
     protected void dispatchDraw(Canvas canvas) {
         int count = getChildCount();
         int top = count > 0 ? getChildAt(0).getTop() : 0;
         int backgroundWidth = background.getWidth();
         int backgroundHeight = background.getHeight()+2;
         int width = getWidth();
         int height = getHeight();

         for (int y = top; y < height; y += backgroundHeight) {
             for (int x = 0; x < width; x += backgroundWidth) {
                 canvas.drawBitmap(background, x, y, null);
             }
         }

         super.dispatchDraw(canvas);
     }

 }

　　上面就是自定义书架的gridview，也是实现书架最核心的方法。

　　然后是每一个item的布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:gravity="center"
    android:orientation="vertical" >
    <TextView
    android:layout_height="110dp"
    android:layout_width="90dp"
    android:layout_marginTop="10dp"
    android:background="@drawable/cover_txt"
    android:id="@+id/imageView1"
    android:text="天龙八部"
    android:padding="15dp"
    android:textColor="#000000"
    />

</LinearLayout>

　　最后就可以在主activity中显示出来了。

 public class BookShelfActivity extends BaseActivity {
     private GridView bookShelf;
     private int[] data = {
             R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,
             R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,
             R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,
             R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,
             R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,
             R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,
             R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,
             R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt,R.drawable.cover_txt

     };
     private String[] name={
             "天龙八部","搜神记","水浒传","黑道悲情"
     };

     private GridView gv;
     private SlidingDrawer sd;
     private Button iv;
     private List<ResolveInfo> apps;  

     /** Called when the activity is first created. */
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         this.requestWindowFeature(Window.FEATURE_NO_TITLE);
         setContentView(R.layout.main);

         bookShelf = (GridView) findViewById(R.id.bookShelf);
         ShlefAdapter adapter=new ShlefAdapter();
         bookShelf.setAdapter(adapter);
         bookShelf.setOnItemClickListener(new OnItemClickListener() {

             @Override
             public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                     long arg3) {
                 // TODO Auto-generated method stub
                 if(arg2>=data.length){

                 }else{
                    Toast.makeText(getApplicationContext(), ""+arg2, Toast.LENGTH_SHORT).show();
                 }
             }
         });
         loadApps();
         gv = (GridView) findViewById(R.id.allApps);
         sd = (SlidingDrawer) findViewById(R.id.sliding);
         iv = (Button) findViewById(R.id.imageViewIcon);
         gv.setAdapter(new GridAdapter());
         sd.setOnDrawerOpenListener(new SlidingDrawer.OnDrawerOpenListener()// 开抽屉
         {
             @Override
             public void onDrawerOpened() {
                 iv.setText("返回");
                 iv.setBackgroundResource(R.drawable.btn_local);// 响应开抽屉事件
                                                                 // ，把图片设为向下的
             }
         });
         sd.setOnDrawerCloseListener(new SlidingDrawer.OnDrawerCloseListener() {
             @Override
             public void onDrawerClosed() {
                 iv.setText("本地");
                 iv.setBackgroundResource(R.drawable.btn_local);// 响应关抽屉事件
             }
         });
     }

     class ShlefAdapter extends BaseAdapter{

         @Override
         public int getCount() {
             // TODO Auto-generated method stub
             return data.length+5;
         }

         @Override
         public Object getItem(int arg0) {
             // TODO Auto-generated method stub
             return arg0;
         }

         @Override
         public long getItemId(int arg0) {
             // TODO Auto-generated method stub
             return arg0;
         }

         @Override
         public View getView(int position, View contentView, ViewGroup arg2) {
             // TODO Auto-generated method stub

             contentView=LayoutInflater.from(getApplicationContext()).inflate(R.layout.item1, null);

             TextView view=(TextView) contentView.findViewById(R.id.imageView1);
             if(data.length>position){
                 if(position<name.length){
                    view.setText(name[position]);
                 }
                 view.setBackgroundResource(data[position]);
             }else{
                 view.setBackgroundResource(data[0]);
                 view.setClickable(false);
                 view.setVisibility(View.INVISIBLE);
             }
             return contentView;
         }

     }

     @Override
     public boolean onKeyDown(int keyCode, KeyEvent event) {
         // TODO Auto-generated method stub

         if (keyCode == KeyEvent.KEYCODE_BACK) {
             AlertDialog.Builder builder = new AlertDialog.Builder(this);
             builder.setMessage("你确定退出吗？")
                     .setCancelable(false)
                     .setPositiveButton("确定",
                             new DialogInterface.OnClickListener() {
                                 public void onClick(DialogInterface dialog,
                                         int id) {
                                     finish();
                                 }
                             })
                     .setNegativeButton("返回",
                             new DialogInterface.OnClickListener() {
                                 public void onClick(DialogInterface dialog,
                                         int id) {
                                     dialog.cancel();
                                 }
                             });
             AlertDialog alert = builder.create();
             alert.show();
             return true;
         }

         return super.onKeyDown(keyCode, event);
     }

     private void loadApps() {
         Intent intent = new Intent(Intent.ACTION_MAIN, null);
         intent.addCategory(Intent.CATEGORY_LAUNCHER);  

         apps = getPackageManager().queryIntentActivities(intent, 0);
     }  

     public class GridAdapter extends BaseAdapter {
         public GridAdapter() {  

         }  

         public int getCount() {
             // TODO Auto-generated method stub
             return apps.size();
         }  

         public Object getItem(int position) {
             // TODO Auto-generated method stub
             return apps.get(position);
         }  

         public long getItemId(int position) {
             // TODO Auto-generated method stub
             return position;
         }  

         public View getView(int position, View convertView, ViewGroup parent) {
             // TODO Auto-generated method stub
             ImageView imageView = null;
             if (convertView == null) {
                 imageView = new ImageView(BookShelfActivity.this);
                 imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
                 imageView.setLayoutParams(new GridView.LayoutParams(50, 50));
             } else {
                 imageView = (ImageView) convertView;
             }  

             ResolveInfo ri = apps.get(position);
             imageView.setImageDrawable(ri.activityInfo
                     .loadIcon(getPackageManager()));  

             return imageView;
         }  

     }  

 }

源码下载：http://download.csdn.net/detail/wangkuifeng0118/4548542