android手把手教你开发launcher（四）——显示widget

由于本人的项目目前暂时不添加小部件，所以我就不做跟着本文做了，以下是原内容。原文地址：http://www.bangchui.org/read.php?tid=12239

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widget

1. 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：

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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

void addWidget() {        int appWidgetId = mAppWidgetHost.allocateAppWidgetId();        Intent pickIntent = new Intent(AppWidgetManager.ACTION_APPWIDGET_PICK);        pickIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);        // start the pick activity        startActivityForResult(pickIntent, [b]REQUEST_PICK_APPWIDGET[/b]);    }

 @Override    protected void onActivityResult(int 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_SHORTCUT.         if (resultCode == RESULT_OK) {            switch (requestCode) {            case REQUEST_PICK_APPWIDGET:                addAppWidget(data);                break;            case REQUEST_CREATE_APPWIDGET:                completeAddAppWidget(data);                break;             }        }    }     void addAppWidget(Intent data) {        // TODO: catch bad widget exception when sent        int appWidgetId = data.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID,                -1);        AppWidgetProviderInfo appWidget = mAppWidgetManager                .getAppWidgetInfo(appWidgetId);         //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 Intent(                    AppWidgetManager.ACTION_APPWIDGET_CONFIGURE);            intent.setComponent(appWidget.configure);            intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);             startActivityForResultSafely(intent, 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            onActivityResult(REQUEST_CREATE_APPWIDGET, Activity.RESULT_OK, data);        }    }     void startActivityForResultSafely(Intent intent, int requestCode) {        try {            startActivityForResult(intent, requestCode);        } catch (ActivityNotFoundException e) {            Toast.makeText(this, "activity_not_found", Toast.LENGTH_SHORT)                    .show();        } catch (SecurityException e) {            Toast.makeText(this, "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 completeAddAppWidget(Intent data) {        Bundle extras = data.getExtras();        int appWidgetId = extras                .getInt(AppWidgetManager.EXTRA_APPWIDGET_ID, -1);         Log.d(TAG, "dumping extras content=" + extras.toString());         AppWidgetProviderInfo appWidgetInfo = mAppWidgetManager                .getAppWidgetInfo(appWidgetId);         // Perform actual inflation because we're live        synchronized (mLock) {                         //获取显示widget的view            mHostView = mAppWidgetHost.createView(this, appWidgetId,                    appWidgetInfo);            mHostView.setAppWidget(appWidgetId, appWidgetInfo);             //将获取的view添加早layout中            LayoutParams lp = new LinearLayout.LayoutParams(                    appWidgetInfo.minWidth, appWidgetInfo.minHeight);            mainLayout.addView(mHostView, lp);             mHostView.requestLayout();        }     }

android手把手教你开发launcher（一）（AndroidStudio版）

android手把手教你开发launcher（二）——列出安装的应用程序

android手把手教你开发launcher（三）——启动安装的应用程序

android手把手教你开发launcher（四）——显示widget

android手把手教你开发launcher（五）——设置壁纸

转自：http://www.bangchui.org/read.php?tid=12239