Android屏幕切换

点击“银行”进入“易惠通 - 银行”屏：

 

GridView屏对应MainActivity；ListView屏对应BankActivity。

这两个Activity都必须定义在xml文件中。

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.pervcom.android.eeway"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/eeway" android:label="@string/app_name">
        <activity android:name="MainActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name="BankActivity"
                  android:label="@string/bank">
        </activity>
        <activity android:name="EBActivity"
                  android:label="@string/ebbank">
        </activity>
    </application>
    <uses-permission android:name="android.permission.INTERNET"></uses-permission>
    <uses-sdk android:minSdkVersion="5" />
</manifest> 

 

点击“银行”时对应的代码段如下，切换到“易惠通 - 银行”调用的方法是startActivity。

@Override
public void onCreate(Bundle savedInstanceState)
{
	super.onCreate(savedInstanceState);
	setContentView(R.layout.main);
	
	//取得GridView对象
	GridView gridview = (GridView) findViewById(R.id.gridview);
	//添加元素给gridview
	gridview.setAdapter(new MainAdapter(this));
	
	//事件监听
	gridview.setOnItemClickListener(new OnItemClickListener() {
		public void onItemClick(AdapterView parent, View v, int position, long id)
		{
			try{
				ApplicationInfo app = (ApplicationInfo) parent.getItemAtPosition(position);
				if(app.intent!=null){
					startActivity(app.intent);
				}
			}catch(Exception ex){
				Log.e(LOG_TAG,"OnItemClickListener",ex);
			}
		}
	});
}

 

ListView对应的数据存储在MainAdapter中，定义如下：

public class MainAdapter extends BaseAdapter {

	// 定义Context
	private Context		mContext;
	
	// 定义易惠通子应用信息
	List<ApplicationInfo> appInfos = new LinkedList<ApplicationInfo>();

	public MainAdapter(Context c)
	{
		mContext = c;
		buildAppInfos();
	}
	
	public void addAppInfo(int iconID, String title, Intent intent){
		ApplicationInfo appInfo = new ApplicationInfo();
		appInfo.icon = this.mContext.getResources().getDrawable(iconID);
		appInfo.icon.setBounds(0, 0, 85, 85);
		appInfo.title = title;
		appInfo.intent = intent;
		appInfos.add(appInfo);
	}
	
	public void buildAppInfos()
	{
		addAppInfo(R.drawable.bank2, "银行", new Intent(mContext,BankActivity.class));
		addAppInfo(R.drawable.shopping_cart, "超市", null);
		addAppInfo(R.drawable.market, "购物中心", null);
		addAppInfo(R.drawable.film_camera_35mm_b, "影剧院", null);
		addAppInfo(R.drawable.food2, "餐饮", null);
		addAppInfo(R.drawable.boot, "公交", null);
		addAppInfo(R.drawable.pay23, "缴费", null);
		addAppInfo(R.drawable.set2, "易惠通设置", null);
	}
	
	public int getCount() {
	
		return appInfos.size();
	}
	
	public Object getItem(int position) {
	
		return appInfos.get(position);		
	}
	
	public long getItemId(int position) {
	
		return position;
	}
	
	public View getView(int position, View convertView, ViewGroup parent) {
	
		ApplicationInfo appInfo = appInfos.get(position);
		TextView textView = new TextView(mContext); 
		textView.setCompoundDrawables(null, appInfo.icon, null, null);
		textView.setText(appInfo.title);
		textView.setTextSize(16);
		textView.setGravity(Gravity.CENTER);
	    textView.setTag(appInfo.intent);
			
		return textView;
	}

}

 

在本文中，最重要的几行代码是：

ApplicationInfo app = (ApplicationInfo) parent.getItemAtPosition(position);
if(app.intent!=null){
	startActivity(app.intent);
}