android - 使用 Picasso 加载已安装的应用程序图标

Question

• 我想获取所有已安装的应用程序图标:

应用详情

public class AppDetail {
private CharSequence name; // Ex: com.google.youtube
private CharSequence label; // Ex: Youtube
private Drawable icon;

// Getters and setters
...
}

AllAppsActivity//在这里我可以获取所有应用程序图标

private void loadAllApps() {
    packageManager = this.getPackageManager();
    appDetailList = new ArrayList<AppDetail>();

    Intent i = new Intent(Intent.ACTION_MAIN, null);
    i.addCategory(Intent.CATEGORY_LAUNCHER);
    List<ResolveInfo> availableActivities = packageManager.queryIntentActivities(i, 0);

    for (ResolveInfo ri : availableActivities) {
        AppDetail appDetail = new AppDetail();
        appDetail.setLabel(ri.loadLabel(packageManager));
        appDetail.setName(ri.activityInfo.packageName);
        appDetail.setIcon(ri.activityInfo.loadIcon(packageManager));
        appDetailList.add(appDetail);
    }
}

现在我想用 Picasso 加载所有图标，但是 Picasso 需要 File/String path/int resouce ID/Uri uri 用于 load() 函数我应该怎么办？提前致谢

Answer 1

我知道这是旧的，但我想我会与遇到此问题的其他人分享我的解决方案。您可以使用自定义 RequestHandler .这是我为使用 Picasso 加载应用程序图标而编写的 RequestHandler:

public class AppIconRequestHandler extends RequestHandler {

  public static final String SCHEME_PNAME = "pname";

  private final PackageManager pm;
  private final int dpi;
  private Bitmap defaultAppIcon;

  public AppIconRequestHandler(Context context) {
    ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    dpi = am.getLauncherLargeIconDensity();
    pm = context.getPackageManager();
  }

  @Override public boolean canHandleRequest(Request data) {
    return data.uri != null && TextUtils.equals(data.uri.getScheme(), SCHEME_PNAME);
  }

  @Override public Result load(Request request, int networkPolicy) throws IOException {
    try {
      return new Result(getFullResIcon(request.uri.toString().split(":")[1]), DISK);
    } catch (PackageManager.NameNotFoundException e) {
      return null;
    }
  }

  private Bitmap getFullResIcon(String packageName) throws PackageManager.NameNotFoundException {
    return getFullResIcon(pm.getApplicationInfo(packageName, 0));
  }

  private Bitmap getFullResIcon(ApplicationInfo info) {
    try {
      Resources resources = pm.getResourcesForApplication(info.packageName);
      if (resources != null) {
        int iconId = info.icon;
        if (iconId != 0) {
          return getFullResIcon(resources, iconId);
        }
      }
    } catch (PackageManager.NameNotFoundException ignored) {
    }
    return getFullResDefaultActivityIcon();
  }

  private Bitmap getFullResIcon(Resources resources, int iconId) {
    final Drawable drawable;
    try {
      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP_MR1) {
        drawable = resources.getDrawableForDensity(iconId, dpi, null);
      } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1) {
        drawable = resources.getDrawableForDensity(iconId, dpi);
      } else {
        drawable = resources.getDrawable(iconId);
      }
    } catch (Resources.NotFoundException e) {
      return getFullResDefaultActivityIcon();
    }
    return drawableToBitmap(drawable);
  }

  private Bitmap getFullResDefaultActivityIcon() {
    if (defaultAppIcon == null) {
      Drawable drawable;
      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1) {
        drawable = Resources.getSystem().getDrawableForDensity(
            android.R.mipmap.sym_def_app_icon, dpi);
      } else {
        drawable = Resources.getSystem().getDrawable(
            android.R.drawable.sym_def_app_icon);
      }
      defaultAppIcon = drawableToBitmap(drawable);
    }
    return defaultAppIcon;
  }

}

用法

只需将 RequestHandler 添加到您的 Picasso 实例:

Picasso.setSingletonInstance(new Picasso.Builder(this)
    .addRequestHandler(new AppIconRequestHandler(this))
    .build());

然后，使用 RequestHandler 中使用的方案创建一个 Uri:

Uri uri = Uri.parse(AppIconRequestHandler.SCHEME_PNAME +  ":" + "com.facebook.katana");
Picasso.with(context).load(uri).into(imageView);