桌面应用基本创建流程

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<--主界面布局-->    <GridView
android:gravity="center_horizontal"
android:stretchMode="columnWidth"
android:columnWidth="100dp"
android:horizontalSpacing="10dp"
android:verticalSpacing="10dp"
android:layout_width="match_parent"
android:id="@+id/apps_list"
android:numColumns="3"
android:layout_height="match_parent">
    </GridView>

</LinearLayout>

-------------------------------------------------------------------------------------------------------------------------------------------------------------------

 <--清单文件中的配置-->
<application
    android:name="com.way.launcher.SceneLauncherApplication"
    android:icon="@drawable/ic_launcher_home"
    android:label="@string/application_name"
    android:theme="@android:style/Theme.Black.NoTitleBar" >
    <activity
        android:name="com.way.launcher.SceneLauncherActivity"
        android:configChanges="orientation|keyboardHidden"
        android:launchMode="singleTask"
        android:screenOrientation="nosensor" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.HOME" />
            <category android:name="android.intent.category.DEFAULT" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name="com.way.launcher.SceneChooserActivity"
        android:configChanges="orientation|keyboardHidden"
        android:launchMode="singleTask"
        android:screenOrientation="nosensor" />
</application>

-----------------------------------------------------------------------------------------------------------------------------------------------------------------

public class MyHome extends Activity {
private List<ResolveInfo> mApps;
GridView mGrid;
private AdapterView.OnItemClickListener listener = new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,long id) {
ResolveInfo info = mApps.get(position);
//设置点击item监听
String pkg = info.activityInfo.packageName;//该应用的包名
String cls = info.activityInfo.name; //应用的主activity类
ComponentName componet = new ComponentName(pkg, cls);//设置跳转
Intent i = new Intent();//发送意图
i.setComponent(componet);
startActivity(i);//启动被点击的activity
}
    };

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
loadApps();
setContentView(R.layout.activity_main);
mGrid = (GridView) findViewById(R.id.apps_list);
mGrid.setAdapter(new AppsAdapter());//由于adapter是内部类，所以直接将数据传入adapter里面了
mGrid.setOnItemClickListener(listener);
}
private void loadApps() {//查询所有安装的应用
Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);
mApps = getPackageManager().queryIntentActivities(mainIntent, 0);
}

public class AppsAdapter extends BaseAdapter {
public AppsAdapter() {}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) {
                imageView = new ImageView(MyHome.this);
imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
imageView.setLayoutParams(new GridView.LayoutParams(100, 100));
} else {
                imageView = (ImageView) convertView;
}
ResolveInfo info = mApps.get(position);
imageView.setImageDrawable(info.activityInfo.loadIcon(getPackageManager()));
return imageView;
}
public final int getCount() {
return mApps.size();
}

public final Object getItem(int position) {
return mApps.get(position);
}

public final long getItemId(int position) {
return position;
}}

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {return false;}//屏蔽返回键
return super.onKeyDown(keyCode, event);
}
}