安卓的原生launcher偶尔出现添加小部件的时候，点击没有效果，没法拖拽的现象。根据现象，大概猜测是google的锅

分析：点击事件有没有传到小部件页面？传到哪里了？我们从头看

长按桌面弹出了，壁纸，小部件，设置的一个popup，点击小部件才跳转到了添加小部件的页面

 

这段逻辑在alps\packages\apps\Launcher3\src\com\android\launcher3\views\OptionsPopupView.java中

public static boolean onWidgetsClicked(View view) {
        return openWidgets(Launcher.getLauncher(view.getContext()));
    }

    public static boolean openWidgets(Launcher launcher) {
        if (launcher.getPackageManager().isSafeMode()) {
            Toast.makeText(launcher, R.string.safemode_widget_error, Toast.LENGTH_SHORT).show();
            return false;
        } else {
            WidgetsFullSheet.show(launcher, true /* animated */);
            return true;
        }
    }

跳转到Y:\10\alps\packages\apps\Launcher3\src\com\android\launcher3\widget\WidgetsFullSheet.java之后，这里并没有想要的代码，于是我们查看WidgetsFullSheet的父类，Y:\10\alps\packages\apps\Launcher3\src\com\android\launcher3\widget\BaseWidgetSheet.java，这里发现了我们想要的代码

    @Override
    public final void onClick(View v) {
        // Let the user know that they have to long press to add a widget
        if (mWidgetInstructionToast != null) {
            mWidgetInstructionToast.cancel();
        }

        CharSequence msg = Utilities.wrapForTts(
                getContext().getText(R.string.long_press_widget_to_add),
                getContext().getString(R.string.long_accessible_way_to_add));
        mWidgetInstructionToast = Toast.makeText(getContext(), msg, Toast.LENGTH_SHORT);
        mWidgetInstructionToast.show();
    }

    @Override
    public boolean onLongClick(View v) {
        if (!ItemLongClickListener.canStartDrag(mLauncher)) return false;

        if (v instanceof WidgetCell) {
            return beginDraggingWidget((WidgetCell) v);
        }
        return true;
    }

长按触发拖拽，但是出现问题的时候发现，if (!ItemLongClickListener.canStartDrag(mLauncher)) return false;，直接返回了false，于是再看看这个方法是什么判断，我们来到Y:\10\alps\packages\apps\Launcher3\src\com\android\launcher3\touch\ItemLongClickListener.java

public static boolean canStartDrag(Launcher launcher) {
        if (launcher == null) {
            return false;
        }
        // We prevent dragging when we are loading the workspace as it is possible to pick up a view
        // that is subsequently removed from the workspace in startBinding().
        if (launcher.isWorkspaceLocked()) return false;
        // Return early if an item is already being dragged (e.g. when long-pressing two shortcuts)
        if (launcher.getDragController().isDragging()) return false;

        return true;
    }

最终发现，这个地方返回了false ， if (launcher.isWorkspaceLocked()) return false;  上面Google备注了返回false的原因，然并卵，他有他的说法，我有我的需求啊！

直接注释掉这句，就完了，反正没啥其他影响。有时候，粗暴一点，就会简单一点！