深入探索Symbian多视图程序开发

我们知道,在大多数GUI的Applications中,视图之间的切换是极其频繁的。那么如何组织这些视图以及视图之间的通讯,就成为大多数Applications所要面对的问题。

在Symbian中多视图应用程序之间的视图管理可以用下图来表示:

其中AppUI管理AppView,而AppView又管理Container。

AppUI继承自CAknViewAppUi,其管理AppView的代码如下:

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CAppView1* iView1 = new(ELeave) CAppView1;

CleanupStack::PushL( iView1 );

videoView->ConstructL();

AddViewL( iView1 );

CleanupStack::Pop();// view1

CAppView2* iView2 = new(ELeave) CAppView2;

CleanupStack::PushL( iView2 );

userView->ConstructL();

AddViewL( iView2);

CleanupStack::Pop();// view2

SetDefaultViewL(*iView1);

CAppView1* iView1 = new(ELeave) CAppView1;

CleanupStack::PushL( iView1 );

videoView->ConstructL();

AddViewL( iView1 );

CleanupStack::Pop();// view1

CAppView2* iView2 = new(ELeave) CAppView2;

CleanupStack::PushL( iView2 );

userView->ConstructL();

AddViewL( iView2);

CleanupStack::Pop();// view2

SetDefaultViewL(*iView1);

而其中每个View又继承自

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class CAppView1: public CAknView , public MCoeControlObserver

class CAppView2: public CAknView , public MCoeControlObserver

class CAppView1: public CAknView , public MCoeControlObserver

class CAppView2: public CAknView , public MCoeControlObserver

View之间要想实现自由的切换,就必须定义一个TUid作为自身的唯一标识并实现CAknView的方法

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// UID of view

const TUid KViewId = {1};

/**

* From CAknView returns Uid of View