MagicNavigationBar

Introduction: Project Background and Overview

As a developer deeply passionate about WPF technology, I firmly believe in its potential far beyond what we usually perceive. WPF is not just a powerful UI framework; its diversity and superior performance offer developers a vast space for creativity. My goal is to gradually unveil these aspects of WPF through various projects, providing technical support and inspiration to those interested in or currently working with WPF technology.

The Design Philosophy of Magic Navigation Bar:

The essence of this project is to create a simplistic yet vibrant Magic Navigation Bar. In the contemporary world of programming, similar navigation bars are typically implemented using HTML, CSS, and JavaScript. The advantage of these technologies lies in their widespread application and flexibility. HTML provides the structure, CSS handles the styling and layout, and JavaScript manages interaction and animation. Together, they create visually appealing and functionally robust web applications.

However, constructing such a project with WPF technology is often perceived as complex and challenging, especially in terms of project structure and animation presentation. This is where the challenge lies: with a deep understanding of the flexibility and powerful capabilities of WPF, not only can this process be simplified, but it can also be elegantly implemented through code.

Project Overview

The Power of WPF:

In this project, we leverage the formidable capabilities of WPF, particularly the rich combination of XAML and C# backend code, to construct a visually appealing and fully functional Magic Navigation Bar. WPF allows us to design UIs using a declarative language (XAML), while utilizing the strong typing and object-oriented features of C# to handle logic and behavior. This combination provides immense flexibility for creating complex and dynamic UIs.

Structure and Implementation:

The project structure is divided into two parts: the frontend UI and the backend logic. In the UI segment, we utilize XAML to define the layout, style, and animations of the controls. This includes defining the appearance of controls, implementing animation effects, and responding to user interactions. In the C# backend code, we handle user interaction events, control the playback of animations, and manage the state changes of controls. This structure not only ensures clarity and maintainability of the code but also separates UI from logic, enhancing the reusability and scalability of the code.

Through this project, we can showcase the powerful capabilities of WPF in creating modern, dynamic, and responsive user interfaces. It also demonstrates that WPF can provide elegant and efficient solutions for projects traditionally considered within the realm of frontend development.

XAML Code Explanation:

Geometry and Layout

The core of the XAML code in the Magic Navigation Bar is centered around the customization of the ListBoxItem and the clever combination of various elements to create a navigation bar that is both aesthetically pleasing and fully functional.

• 1.ListBoxItem Structure:

  • The ListBoxItem serves as the basic building block of the MagicBar. Each ListBoxItem includes an Icon (using JamesIcon) and text (using TextBlock). This structure provides each navigation item with an icon and a corresponding text label, offering an intuitive navigation experience for users.

• 2.Use and Customization of Icons:

  • With the jamesnet.wpf library, it becomes easy to add and use a variety of icon materials. This greatly simplifies the process of using icons and allows for the customization of the icons' size and color through custom controls. Such flexibility ensures that each item in the MagicBar is unique yet maintains consistency.

• 3.Application of RelativeSource Binding:

  • By employing RelativeSource Binding, we can move the TemplateBinding of Icons and Texts, initially defined within the ListBoxItem area, to the JamesIcon and TextBlock areas for individual management. This approach allows each component (Icon and Text) to have its own definition and style, making the code more modular, easier to maintain, and reusable. Separating bindings and styles into their respective areas clarifies the overall code structure, making it easier to understand and modify. Furthermore, this separation also provides greater flexibility, as it allows for the individual styling and behavior adjustment of different components without affecting others.

2. Analysis of the Visual Design of the Circle Component

In the Magic Navigation Bar project, the Circle component is a visual highlight that enhances the appeal of the entire navigation bar through its ingenious design and technical execution.

We create a sense of spatial depth and layering by adding two circles with different positions and colors. Additionally, to ensure a natural transition from the Circle component to the MagicBar area, we designed a smooth and flowing multi-arc graphic. In WPF, there are various ways to implement such graphics, including using pre-drawn images or directly drawing in the project using the Path attribute. However, due to the unique nature and complexity of the graphic, we sought a simpler and more convenient method.

This approach reminded me of my recent foray into 3D printing, where I often used merging and boolean functions in Blender software to create special-shaped 3D models. In Microsoft Blend, similar methods can be applied to create complex graphics.

The design process involved using a large circle to create a downward protruding arc at the bottom, then adding a smaller circle on each side of the large circle at the same height. By adjusting the diameter of the large circle, we ensured that the large and small circles intersected just right. Next, we used the merge function to remove the unnecessary part of the large circle, followed by the subtract function to eliminate the unwanted parts of the small circles, leaving only the arc shape at the intersections. Finally, by adding a rectangle and removing the unnecessary parts, we achieved a special and natural arc shape.

This innovative design method not only showcases the powerful capabilities of WPF and Blend in handling complex graphics but also offers a new perspective in thinking about and solving design challenges. Through this approach, the Circle component's design is not only aesthetically pleasing but also innovative and flexible in its technical execution, adding unique charm to the entire Magic Navigation Bar.

3.Animation Creation

ListBoxItem Area Icon and Text Movement Animation:

• We can implement the animation of the icon and text moving up and down in the ListBoxItem area by adding an IsSelected property trigger in XAML. This allows us to define the behavior when a ListBoxItem is selected or deselected.

Storyboard Concept:

A Storyboard in WPF is a container used to define a series of animations. It can contain multiple animation elements that play sequentially or simultaneously on a timeline, creating complex animation sequences. Here, by adding Selected and UnSelected Storyboards, we display the animation effect of the icon and text moving positions while simultaneously changing colors.

Animation Properties:

• Mode:
  • CubicEaseInOut is an easing function used to control the acceleration and deceleration of the animation, making it appear more natural.
• TargetName:
  • Specifies the name of the element to which the animation is applied.
• Duration:
  • The total duration of the animation.
• Property:
  • Defines the property to be animated, such as Margin or Fill.Color.

Circle Component Movement:

The movement of the circle component needs to be precisely calculated based on the clicked position, and therefore cannot be implemented in XAML but needs to be done in C# code.

• OnApplyTemplate Method:

This is an important method in the lifecycle of the MagicBar control. It is called when the control’s template is applied. Inside the method, we first call the base class’s OnApplyTemplate method to ensure all standard initialization steps are executed. Then, using the GetTemplateChild method, we retrieve the Grid element named "PART_Circle". This Grid is likely the target element for the animation, displaying the animation effect during user interaction.

• InitStoryboard Method:

This method is responsible for initializing the animation. It first creates instances of ValueItem (_vi) and Storyboard (_sb). The easing function set for ValueItem is QuinticEaseInOut, which slows down at the start and end of the animation and accelerates in the middle, making the animation appear smooth and natural. The animation affects the property Canvas.LeftProperty, indicating that the animation will change the horizontal position of the target element. The duration of the animation is set to 0.5 seconds. Finally, the animation target is set to the passed circle (Grid) element, and the animation is added to the storyboard.

• OnSelectionChanged Method:

This overridden method is triggered when the selected item in MagicBar changes. The method first calls the base class’s OnSelectionChanged method to ensure standard behavior is executed. Then, it sets the _vi’s To property based on the index of the selected item, determining the value of Canvas.LeftProperty at the end of the animation. The animation moves the element to a position proportional to the SelectedIndex. Lastly, by calling _sb.Begin(), the storyboard is started, and the animation is played.