使用框架编写Android程序

AndroidAnnotations这个开源项目为android程序的编写提供了一个新的思路，他们自己称之为框架，我觉得很像struts2的注解方式，下面是这个项目在github上面的地址

https://github.com/excilys/androidannotations

下面的代码是一个例子

package com.googlecode.androidannotations.helloworldeclipse;

import java.util.Date;
import java.util.concurrent.TimeUnit;

import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.googlecode.androidannotations.annotations.Background;
import com.googlecode.androidannotations.annotations.Click;
import com.googlecode.androidannotations.annotations.EActivity;
import com.googlecode.androidannotations.annotations.LongClick;
import com.googlecode.androidannotations.annotations.SystemService;
import com.googlecode.androidannotations.annotations.Touch;
import com.googlecode.androidannotations.annotations.Transactional;
import com.googlecode.androidannotations.annotations.UiThread;
import com.googlecode.androidannotations.annotations.ViewById;
import com.googlecode.androidannotations.annotations.res.BooleanRes;
import com.googlecode.androidannotations.annotations.res.ColorRes;
import com.googlecode.androidannotations.annotations.res.StringRes;

@EActivity(R.layout.my_activity) //布局文件在这里声明，不用在setContentView
public class MyActivity extends Activity {

    @ViewById  //控件这样标注，由于是IOC模式，因此不需要自己实例化
    EditText myEditText;

    @ViewById(R.id.myTextView) //提供id来生成控件，如果不指定ID，默认以控件名进行查找，如上面的myEditText
    TextView textView;

    @StringRes(R.string.hello)  //资源
    String helloFormat;

    @ColorRes
    int androidColor;

    @BooleanRes
    boolean someBoolean;

    @SystemService
    NotificationManager notificationManager;

    @SystemService
    WindowManager windowManager;

    /**
     * AndroidAnnotations gracefully handles support for onBackPressed, whether
     * you use ECLAIR (2.0), or pre ECLAIR android version.
     */
    public void onBackPressed() {
        Toast.makeText(this, "Back key pressed!", Toast.LENGTH_SHORT).show();
    }
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // windowManager should not be null
        windowManager.getDefaultDisplay();
        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
    }


    @Click //事件控制，可以以按钮的id作为方法名,同时支持的事件还有onLongClick，onTextChange等
    void myButtonClicked() {
        String name = myEditText.getText().toString();
        setProgressBarIndeterminateVisibility(true);
        someBackgroundWork(name, 5);
    }

    @Background //开启新线程后台运行，注意不要引用UI控件,而且返回值类型一定是void
    void someBackgroundWork(String name, long timeToDoSomeLongComputation) {
        try {
            TimeUnit.SECONDS.sleep(timeToDoSomeLongComputation);
        } catch (InterruptedException e) {
        }

        String message = String.format(helloFormat, name);

        updateUi(message, androidColor);

        showNotificationsDelayed();
    }

    @UiThread //UI线程
    void updateUi(String message, int color) {
        setProgressBarIndeterminateVisibility(false);
        textView.setText(message);
        textView.setTextColor(color);
    }

    @UiThread(delay=2000)  //可以设置延时时间，以毫秒为单位
    void showNotificationsDelayed() {
        Notification notification = new Notification(R.drawable.icon, "Hello !", 0);
        PendingIntent contentIntent = PendingIntent.getActivity(this, 0, new Intent(), 0);
        notification.setLatestEventInfo(getApplicationContext(), "My notification", "Hello World!", contentIntent);
        notificationManager.notify(1, notification);
    }

    @LongClick
    void startExtraActivity() {
        Intent intent = new Intent(this, ActivityWithExtra_.class);

        intent.putExtra(ActivityWithExtra.MY_DATE_EXTRA, new Date());
        intent.putExtra(ActivityWithExtra.MY_STRING_EXTRA, "hello !");
        intent.putExtra(ActivityWithExtra.MY_INT_EXTRA, 42);

        startActivity(intent);
    }

    @Click
    void startListActivity(View v) {
        startActivity(new Intent(this, MyListActivity_.class));
    }

    @Touch
    void myTextView(MotionEvent event) {
        Log.d("MyActivity", "myTextView was touched!");
    }

    @Transactional
    int transactionalMethod(SQLiteDatabase db, int someParam) {
        return 42;
    }

}

这个项目的好处是使用到了IOC模式，代码量小而且简洁，使程序员更多的关注于业务逻辑而不是页面，而且@Backgroud这个标签下开启的线程在线程池中管理。

类似的项目还有AndroidBinding，RoboGuice等，有兴趣可以看一下这个文章

CLEANCODEINANDROIDAPPLICATIONS一个Springgay写得，很不错哦~

http://blog.springsource.com/2011/08/26/clean-code-with-android/