学步园

1.系统应用程序界面

 获取系统程序ApplicationInfo集合

private void loadApplications(boolean isLaunching) {
		if (isLaunching && mApplications != null) {
			return;
		}

		PackageManager manager = getPackageManager();

		Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
		mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);

		final List<ResolveInfo> apps = manager.queryIntentActivities(mainIntent, 0);
		Collections.sort(apps, new ResolveInfo.DisplayNameComparator(manager));

		if (apps != null) {
			final int count = apps.size();

			if (mApplications == null) {
				mApplications = new ArrayList<ApplicationInfo>(count);
			}
			mApplications.clear();

			for (int i = 0; i < count; i++) {
				ApplicationInfo application = new ApplicationInfo();
				ResolveInfo info = apps.get(i);

				application.title = info.loadLabel(manager);
				application.setActivity(new ComponentName(info.activityInfo.applicationInfo.packageName,
						info.activityInfo.name), Intent.FLAG_ACTIVITY_NEW_TASK
						| Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
				application.icon = info.activityInfo.loadIcon(manager);

				mApplications.add(application);
			}
		}
	}

程序列表构造器

private class ApplicationsAdapter extends ArrayAdapter<ApplicationInfo> {
  private Rect mOldBounds = new Rect();
  public ApplicationsAdapter(Context context, ArrayList<ApplicationInfo> apps) {
   super(context, 0, apps);
  }
  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
   final ApplicationInfo info = mApplications.get(position);
   if (convertView == null) {
    final LayoutInflater inflater = getLayoutInflater();
    convertView = inflater.inflate(R.layout.application, parent, false);
   }
   Drawable icon = info.icon;
   if (!info.filtered) {
       int width = 42;// (int)
       int height = 42;// (int)
    final int iconWidth = icon.getIntrinsicWidth();
    final int iconHeight = icon.getIntrinsicHeight();
    if (icon instanceof PaintDrawable) {
     PaintDrawable painter = (PaintDrawable) icon;
     painter.setIntrinsicWidth(width);
     painter.setIntrinsicHeight(height);
    }
    if (width > 0 && height > 0 && (width < iconWidth || height < iconHeight)) {
     final float ratio = (float) iconWidth / iconHeight;
     if (iconWidth > iconHeight) {
      height = (int) (width / ratio);
     } else if (iconHeight > iconWidth) {
      width = (int) (height * ratio);
     }
     final Bitmap.Config c = icon.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
       : Bitmap.Config.RGB_565;
     final Bitmap thumb = Bitmap.createBitmap(width, height, c);
     final Canvas canvas = new Canvas(thumb);
     canvas.setDrawFilter(new PaintFlagsDrawFilter(Paint.DITHER_FLAG, 0));
     mOldBounds.set(icon.getBounds());
     icon.setBounds(0, 0, width, height);
     icon.draw(canvas);
     icon.setBounds(mOldBounds);
     icon = info.icon = new BitmapDrawable(thumb);
     info.filtered = true;
    }
   }
   final TextView textView = (TextView) convertView.findViewById(R.id.label);
   textView.setTextColor(Color.BLACK);
   if (color != null && color.length() == 10) {
    int col_int = ByteHelper.string2color(color);
    textView.setTextColor(col_int);
   }else {
    textView.setTextColor(Color.BLUE);
   }
   textView.setCompoundDrawablesWithIntrinsicBounds(null, icon, null, null);
   textView.setText(info.title);
   return convertView;
  }
 }


添加构造，并设置监听
  mGrid.setAdapter(new ApplicationsAdapter(Home_activity.this, mApplications));
  mGrid.setSelection(0);
  mGrid.setOnItemClickListener(new ApplicationLauncher());
监听
private class ApplicationLauncher implements AdapterView.OnItemClickListener {
  public void onItemClick(AdapterView parent, View v, int position, long id) {
   ApplicationInfo app = (ApplicationInfo) parent.getItemAtPosition(position);
   startActivity(app.intent);
  }
 }