Android进阶篇抽屉样式

抽屉样式作为一种比较常用的View，有很多实现方式。

这里是一种简单的实现方式：

第一步：布局文件

    <!-- android:content 要展开的layout content
         android:handle 委托要展开的图片  -->
    <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" >

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

        <ImageView
            android:id="@+id/imageViewIcon"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/ic_launcher" />
    </SlidingDrawer>

第二部：MainActivity

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        Intent intent = new Intent(Intent.ACTION_MAIN, null);
        intent.addCategory(Intent.CATEGORY_LAUNCHER);
        apps = getPackageManager().queryIntentActivities(intent, 0);
        
        gv = (GridView) findViewById(R.id.allApps);
        sd = (SlidingDrawer) findViewById(R.id.sliding);
        iv = (ImageView) findViewById(R.id.imageViewIcon);
        
        gv.setAdapter(new GridAdapter());
        
        sd.setOnDrawerOpenListener(new SlidingDrawer.OnDrawerOpenListener(){// 开抽屉
            @Override
            public void onDrawerOpened() {
                iv.setImageResource(R.drawable.ic_launcher);
            }
        });
        
        sd.setOnDrawerCloseListener(new SlidingDrawer.OnDrawerCloseListener() {
            @Override
            public void onDrawerClosed() {
                iv.setImageResource(R.drawable.ic_launcher);// 响应关抽屉事件
            }
        });
    }

    //适配器
    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;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub
            ImageView imageView = null;
            
            if (convertView == null) {
                imageView = new ImageView(MainActivity.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;
        }

    }