强制打开CEikEdwin关联的虚拟键盘

文章信息

---

代码示例

源文件: Media:HelloWorld(LaunchVKB).zip

---

文章

翻译:

翻译自: How to force launch of VKB in CEikEdwin

由 chenziteng

最后由 hamishwillee 在 22 Dec 2011 编辑

概述

有些开发者希望虚拟键盘能够自动打开，而不是等用户第一次点击编辑框时打开。本文描述了如何通过模拟用户点击操作强制打开CEikEdwin关联的虚拟键盘。

方案

解决本问题的方案是模拟用户点击CEikEdwin的操作。

void CHelloWorldContainer::LaunchVBKL()
	{
	if(iEdit1!=NULL)
		{
		TCursorSelection sel = iEdit1->Selection(); // remember the selection
 
		const TInt KBorderWidth = 2;
		const TInt KBorderHeight = 2;
		TPointerEvent event;
		event.iType = TPointerEvent::EButton1Down;
		event.iParentPosition = iEdit1->PositionRelativeToScreen()+TPoint(KBorderWidth,KBorderHeight);
		event.iPosition = iEdit1->Position()+TPoint(KBorderWidth,KBorderHeight);
		iEdit1->HandlePointerEventL(event); // simulate a pointer down event
		event.iType = TPointerEvent::EButton1Up;
		iEdit1->HandlePointerEventL(event); // and then simulate a pointer up event to complete the touch operation
 
		iEdit1->SetCursorPosL(sel.iAnchorPos, EFalse);
		iEdit1->SetCursorPosL(sel.iCursorPos, ETrue); // restore the selection
		}	
	}

注意以上代码在（容器对象的ConstructL里）CEikEdwin对象刚刚构造完成时调用无效，因此如果想在容器对象构造完成后立即显示虚拟键盘的话，应该启动一个活动对象并在RunL()中调用上述方法。

void CHelloWorldContainer::ConstructL( 
		const TRect& aRect, 
		const CCoeControl* aParent, 
		MEikCommandObserver* aCommandObserver )
	{
	...
// begin by chen
	iAsyncCallBack = new(ELeave) CAsyncCallBack(TCallBack(AsyncCallBack, this), CActive::EPriorityStandard);
	iAsyncCallBack->CallBack(); // AO that runs only once
// end by chen
	}
...
TInt CHelloWorldContainer::AsyncCallBack(TAny* aParam)
	{
	if(aParam==NULL)
		{
		return KErrNoMemory;
		}
	CHelloWorldContainer* self = static_cast<CHelloWorldContainer*>(aParam);
	TRAPD(err, self->LaunchVBKL());
	return err;
	}

完整的示例程序: HelloWorld(LaunchVKB).zip

相关文档 (和讨论):

VKB

How to force launch of VKB in FEP-aware custom control

"How to pop up virtual keyboard when view is shown"