Android网络编程之一个Android下菜单系统模块的实现(主操作界面)

我们向上一个系统中增加一些功能，在成功登陆后，跳转到一个主操作界面，此界面为所有功能的入口，用一个GridView来实现

GridView的经典实现方法流程：布局文件中声明GridView ---> 编写一个ImageAdapter继承BaseAdapter并主要复写getView()方法 ---> 给GridView添加此adapter

布局文件很简单：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
    
    <GridView 
        android:id="@+id/gridView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:columnWidth="90dp"
        android:numColumns="auto_fit"
        android:verticalSpacing="10dp"
        android:horizontalSpacing="10dp"
        android:stretchMode="columnWidth"
        android:gravity="center"
        />
        
</LinearLayout>

主Activity同样很简单，放在com.moka.activities中：

public class MainMenuActivity extends Activity {
    
    private GridView gridView = null;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_menu);
        
        gridView = (GridView) findViewById(R.id.gridView);
        gridView.setAdapter(new ImageAdapter(this));
    }
    
}

ImageAdapter的编写稍微复杂，因为在这里我们把所用监听事件均放在这里处理，在这里我们先添加的是点菜功能，所以姑且把别的监听事件做简单处理

它放在com.moka.provider中：

public class ImageAdapter extends BaseAdapter {
    
    private Context context = null;
    
    // 所需的图片资源
    private Integer[] functionImgs = { R.drawable.diancai, R.drawable.bingtai, R.drawable.zhuantai,
            R.drawable.chatai, R.drawable.gengxin, R.drawable.shezhi,
            R.drawable.zhuxiao, R.drawable.jietai };
    
    public ImageAdapter(Context context) {
        this.context = context;
    }
    
    @Override
    public int getCount() {
        return functionImgs.length;
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // 准备向GridView中填充的ImageView图片与其一些参数
        ImageView imageView = null;
        if (convertView == null) {
            imageView = new ImageView(context);
            imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
            imageView.setPadding(8, 8, 8, 8);
        } else {
            imageView = (ImageView) convertView;
        }
        // 设置图片源
        imageView.setImageResource(this.functionImgs[position]);
        
        // 设置监听事件
        switch (position) {
        case 0:
            imageView.setOnClickListener(new OrderListener());
            break;
        case 1:
            imageView.setOnClickListener(new UnionTableListener());
            break;
        case 2:
            imageView.setOnClickListener(new ChangeTableListener());
            break;
        case 3:
            imageView.setOnClickListener(new CheckTableListener());
            break;
        case 4:
            imageView.setOnClickListener(new UpdateListener());
            break;
        case 5:
            imageView.setOnClickListener(new SetupListener());
            break;
        case 6:
            imageView.setOnClickListener(new ExitListener());
            break;
        case 7:
            imageView.setOnClickListener(new PayListener());
            break;
        }
        
        return imageView;
    }
    
    private class OrderListener implements OnClickListener {

        @Override
        public void onClick(View v) {
            Intent intent = new Intent(context, OrderActivity.class);
            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            context.startActivity(intent);
        }
        
    }
    private class UnionTableListener implements OnClickListener {
        
        @Override
        public void onClick(View v) {
            Toast.makeText(context, "并台！", Toast.LENGTH_SHORT).show();
        }
        
    }
    private class ChangeTableListener implements OnClickListener {
        
        @Override
        public void onClick(View v) {
            Toast.makeText(context, "转台！", Toast.LENGTH_SHORT).show();
        }
        
    }
    private class CheckTableListener implements OnClickListener {
        
        @Override
        public void onClick(View v) {
            Toast.makeText(context, "查台！", Toast.LENGTH_SHORT).show();
        }
        
    }
    private class UpdateListener implements OnClickListener {
        
        @Override
        public void onClick(View v) {
            Toast.makeText(context, "更新！", Toast.LENGTH_SHORT).show();
        }
        
    }
    private class SetupListener implements OnClickListener {
        
        @Override
        public void onClick(View v) {
            Toast.makeText(context, "设置！", Toast.LENGTH_SHORT).show();
        }
        
    }
    private class ExitListener implements OnClickListener {
        
        @Override
        public void onClick(View v) {
            Toast.makeText(context, "注销！", Toast.LENGTH_SHORT).show();
        }
        
    }
    private class PayListener implements OnClickListener {
        
        @Override
        public void onClick(View v) {
            Toast.makeText(context, "结台！", Toast.LENGTH_SHORT).show();
        }
        
    }

}

关于点菜的OrderActivity及其服务器端有一定的难度，我们稍后再讨论，先看一下主操作界面效果：