基于android手把手教你开发launcher.doc

基于android手把手教你开发launcher launcher,也就是android的桌面应用程序。下图是android2.3的launcher应用程序:?接下来我们要开发一个自己的launcher,使其替代系统的默认launcher。怎样使我们的应用程序成为一个launcher?下面我们就新建一个叫做MyHome的工程,具体步骤略。创建完工程后整个目录结构如下图:现在我们的AndroidManifest.xml文件这样的:?xml version1.0 encodingutf-8?manifest xmlns:android/0.?package/.ome?android:versionCode1?android:versionName1.0application android:icondrawable/icon android:labelstring/app_nameactivity android:name.MyHome?android:labelstring/app_name?intent-filter?action android:name/.ion.MAIN /?category android:name/.egory.LAUNCHER /?/intent-filter请注意intent-filter/intent-filter里面的内容。下面我们在其中添加上以下两行:12category android:name/.egory.HOME /category android:name/.egory.DEFAULT /此时AndroidManifest.xml文件是这样:1234567891011121314151617181920?xml version1.0 encodingutf-8?manifest xmlns:android/.?package/.ome?android:versionCode1?android:versionName1.0application android:icondrawable/icon android:labelstring/app_nameactivity android:name.MyHome?android:labelstring/app_name?intent-filter?action android:name/.ion.MAIN /?category android:name/.egory.LAUNCHER /?category android:name/.egory.HOME /?category android:name/.egory.DEFAULT /?/intent-filter此时运行程序,我们看不到任何特别之处。当按下home键时(模拟器上按下home会调出桌面应用),程序如图:我们看到了,我们开发的Myhome跟Launcher出现在了一起。?重启模拟器,我们看到我们自己的程序已经可以作为home来运行了。ok。 第一步完成了:把我们的应用程序作为home。总结一下:要把我们的应用程序作为home,只需要在AndroidManifest.xml中添加:?category android:name/.egory.HOME /?category android:name/.egory.DEFAULT /android手把手教你开发launcher (二)第二课:列出安装的应用程序预备知识: GridView的使用 改写BaseAdapter?列出已经安装的应用程序是作为launcher比不可少的功能。下面我们就讲解怎样将应用程序列出来。程序运行后的样子如下:一. 修改main.xml,在其中添加一个GridView用来显示应用程序列表。修改后如下:123456789101112?xml version1.0 encodingutf-8?LinearLayout xmlns:android/.?android:orientationvertical android:layout_widthfill_parent?android:layout_heightfill_parent?GridView android:layout_widthmatch_parentandroid:id+id/apps_listandroid:numColumns4android:layout_heightwrap_content二通过PackageManager的api 查询已经安装的apk我们写一个叫做loadApps的方法将活得的应用程序列表放到private List mApps; 中,如下:123456private void loadApps Intent mainIntent new IntentIntent.ACTION_MAIN, null;/.EGORY_LAUNCHER;?mApps getPackageManager.queryIntentActivitiesmainIntent, 0;?三. 实现用于显示Gridview的Adapter,使其显示获得的应用程序列表直接上代码:123456789101112131415161718192021222324252627282930313233343536373839404142public class AppsAdapter extends BaseAdapter public AppsAdapter ?public View getViewint position, View convertView, ViewGroup parent ?ImageView i;?if convertView null ?i new ImageViewMyHome.this;?/.leType.FIT_CENTER;?i.setLayoutParamsnew GridView.LayoutParams50, 50;? else ?i ImageView convertView;?ResolveInfo info mApps.getposition;?/.ivityInfo.loadIcongetPackageManager;?return i;?public final int getCount ?return mApps.size;?public final Object getItemint position ?return mApps.getposition;?public final long getItemIdint position ?return position;?最后整个Activity的代码如下123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687package /.ome;?import /.t;?import /.ivity;import /.ent;import /.ResolveInfo;import /.dle;import /.w;import /.wGroup;import /.eAdapter;import /.dView;import /.geView;?public class MyHome extends Activity ?GridView mGrid;?/* Called when the activity is first created. */?Override?public void onCreateBundle savedInstanceState super.onCreatesavedInstanceState;?loadApps;/.n;mGrid GridView /.s_list;mGrid.setAdapternew AppsAdapter;?private List mApps;private void loadApps Intent mainIntent new IntentIntent.ACTION_MAIN, null;/.EGORY_LAUNCHER;?mApps getPackageManager.queryIntentActivitiesmainIntent, 0;?public class AppsAdapter extends BaseAdapter public AppsAdapter ?public View getViewint position, View convertView, ViewGroup parent ?ImageView i;?if convertView null ?i new ImageViewMyHome.this;?/.leType.FIT_CENTER;?i.setLayoutParamsnew GridView.LayoutParams50, 50;? else ?i ImageView convertView;?ResolveInfo info mApps.getposition;?/.ivityInfo.loadIcongetPackageManager;?return i;?public final int getCount ?return mApps.size;?public final Object getItemint position ?return mApps.getposition;?public final long getItemIdint position ?return position;?第三课 启动安装的应用程序1. 监听GridView的onItemClick事件设置一个监听器是为了当gridView的某项被点击时,会有一个回调函数通知我们。我们调用mGrid.setOnItemClickListenerlistener; 设置一个监听器mGrid.setOnItemClickListenerlistener中的listener是一个接口,其类型为:/.pterView.OnItemClickListener,如下图所示:下面我们new一个/.pterView.OnItemClickListener类型的对象作为参数。我们直接使用eclipde的自动补全功能来完成OnItemClickListener 的定义:12345private OnItemClickListener listener new OnItemClickListener Overridepublic void onItemClickAdapterView? parent, View view, int position,long id ;接口OnItemClickListener 中有一个方法叫做onItemClick,我们实现它即可。下面我对onItemClick的几个参数略作说明:parent? 略view?被点击的viewposition? 被点击项的位置id 被点击项的id2.启动被点击应用的activity一般来讲,我们根据position即可知道被点击的项目是哪一项了。现在我们根据被点击的项目,取出对应的应用程序数据(主要是其中的主activity),然后启动activity。用下面代码实现:123456789101112131415Overridepublic void onItemClickAdapterView? parent, View view, int position,long id ?ResolveInfo info mApps.getposition;/该应用的包名?String pkg /.kageName;?/应用的主activity类?String cls /.e;ComponentName componet new ComponentNamepkg, cls;Intent i new Intent;?i.setComponentcomponet;?startActivityi;例如,我们点击计算器时,启动了计算器,如下图:现在整个类代码如下:复制代码package /.ome;import /.t;import /.ivity;import /.ponentName;import /.ent;import /.ResolveInfo;import /.dle;import /.w;import /.wGroup;import /.pterView;import /.eAdapter;import /.dView;import /.geView;import /.pterView.OnItemClickListener;public class MyHome extends Activity ?private List mApps;?GridView mGrid;?private OnItemClickListener listener new OnItemClickListener Overridepublic void onItemClickAdapterView? parent, View view, int position,long id ?ResolveInfo info mApps.getposition;?/该应用的包名?String pkg /.kageName;?/应用的主activity类?String cls /.e;?ComponentName componet new ComponentNamepkg, cls;?Intent i new Intent;?i.setComponentcomponet;?startActivityi;?;?/* Called when the activity is first created. */?Override?public void onCreateBundle savedInstanceState super.onCreatesavedInstanceState;loadApps;/.n;mGrid GridView /.s_list;mGrid.setAdapternew AppsAdapter;mGrid.setOnItemClickListenerlistener;?private void loadApps Intent mainIntent new IntentIntent.ACTION_MAIN, null;/.EGORY_LAUNCHER;mApps getPackageManager.queryIntentActivitiesmainIntent, 0;?public class AppsAdapter extends BaseAdapter public AppsAdapter public View getViewint position, View convertView, ViewGroup parent ?ImageView i;?if convertView null ?i new ImageViewMyHome.this;?/.leType.FIT_CENTER;?i.setLayoutParamsnew GridView.LayoutParams50, 50;? else ?i ImageView convertView;?ResolveInfo info mApps.getposition;?/.ivityInfo.loadIcongetPackageManager;?return i;public final int getCount ?return mApps.size;public final Object getItemint position ?return mApps.getposition;public final long getItemIdint position ?return position;?我们在前面的课程中已经列出了安装的应用程序,并且点击后可以启动应用程序了!下面我们来研究如何显示widget。源代码:?附件出售:TestWidget.7z?我们要达到这样的效果:点击“add widget” 后弹出widget列表,之后选择一个widget后显示在界面上,如下:第四课:显示widget1. 获取widget信息获取widget其实非常简单,我们只需要发送一个请求到系统,系统就会打开widget的列表,然后我们选择一个即可。代码如下:1234567void addWidget int appWidgetId mAppWidgetHost.allocateAppWidgetId;Intent pickIntent new IntentAppWidgetManager.ACTION_APPWIDGET_PICK;/.RA_APPWIDGET_ID, appWidgetId;/ start the pick activitystartActivityForResultpickIntent, bREQUEST_PICK_APPWIDGET/b;?2. 添加widget的view到layout中当选择一个widget后会通过onActivityResult 通知到activity,widget的信息被包含在 Intent data中,详情看代码注释1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889?Override?protected void onActivityResultint requestCode, int resultCode, Intent data / The pattern used here is that a user PICKs a specific application,/ which, depending on the target, might need to CREATE the actual/ target/ For example, the user would PICK_SHORTCUT for Music playlist, and/ we/ launch over to the Music app to actually CREATE_SHORTCUTif resultCode RESULT_OK ?switch requestCode ?case REQUEST_PICK_APPWIDGET:?addAppWidgetdata;?break;?case REQUEST_CREATE_APPWIDGET:?completeAddAppWidgetdata;?break;?void addAppWidgetIntent data / TODO: catch bad widget exception when sentint appWidgetId /.RA_APPWIDGET_ID,?-1;AppWidgetProviderInfo appWidget mAppWidgetManagergetAppWidgetInfoappWidgetId;?/widget 包含设置信息不为空,则启动widget的设置界面if appWidget.configure ! null ?/ Launch over to configure widget, if needed?Intent intent new IntentAppWidgetManager.ACTION_APPWIDGET_CONFIGURE;?/.figure;?/.RA_APPWIDGET_ID, appWidgetId;startActivityForResultSafelyintent, REQUEST_CREATE_APPWIDGET; else /?widget 包含设置信息为空,直接添加widget到layout中?/ Otherwise just add it?onActivityResultREQUEST_CREATE_APPWIDGET, Activity.RESULT_OK, data;?void startActivityForResultSafelyIntent intent, int requestCode try ?startActivityForResultintent, requestCode; catch ActivityNotFoundException e ?Toast.makeTextthis, activity_not_found, Toast.LENGTH_SHORT.show; catch SecurityException e ?Toast.makeTextthis, activity_not_found, Toast.LENGTH_SHORT.show;?/* 添加widget信息到layout中?* param data 包含了widget的信息*/?private void completeAddAppWidgetIntent data Bundle extras data.getExtras;int appWidgetId extrasgetIntAppWidgetManager.EXTRA_APPWIDGET_ID, -1;?Log.dTAG, dumping extras content + extras.toString;?AppWidgetProviderInfo appWidgetInfo mAppWidgetManagergetAppWidgetInfoappWidgetId;?/ Perform actual inflation because were livesynchronized mLock /获取显示widget的view?mHostView mAppWidgetHost.createViewthis, appWidgetId,appWidgetInfo;?mHostView.setAppWidgetappWidgetId, appWidgetInfo;/将获取的view添加早layout中?LayoutParams lp new /.Width, appWidgetInfo.minHeight;?mainLayout.addViewmHostView, lp;mHostView.requestLayout;?显示壁纸也是launcher必不可少的功能,下面我们看看如何让我们开发的launcher来显示壁纸。新建一个叫做ShowWallpaper的工程,具体步骤略。一. 显示壁纸要在我们的activity里显示一个壁纸非常简单