Скачать или смотреть Drawing Diagonal Lines in WPF with MVVM Control

Learn how to create diagonal lines between controls in WPF using a custom control approach for better visual representation in your applications.
---
This video is based on the question https://stackoverflow.com/q/68982023/ asked by the user 'RBCSharp' ( https://stackoverflow.com/u/16045607/ ) and on the answer https://stackoverflow.com/a/68996772/ provided by the user 'grek40' ( https://stackoverflow.com/u/5265292/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Wpf drawing diagonal lines between image and mvvm control

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Drawing Diagonal Lines in WPF with MVVM Control

In modern application development using WPF (Windows Presentation Foundation), creating interactive and visually appealing user interfaces can sometimes be challenging, particularly when it comes to visually connecting different components on the screen. A common requirement is to draw diagonal lines between various controls, such as sensors and data display elements. If you've ever found yourself grappling with this issue, you're not alone. Let's explore how to effectively create diagonal lines using a custom control approach within the MVVM (Model-View-ViewModel) architecture.

The Problem: Connecting Sensors to Controls

Imagine you have a WPF application featuring a house image with humidity sensors represented by ellipses. Each sensor needs to visually connect to a corresponding control displaying its readings, but how do you achieve angled connections without losing the flexibility of a grid layout?

Key Challenges:

Drawing diagonal lines while maintaining the correct positioning of controls.

Utilizing a flexible layout system like a grid rather than a fixed canvas.

The Solution: Custom Line Connector Control

To tackle the problem of drawing diagonal lines within a grid layout, the ideal solution is to create a custom control that draws lines connecting any two other controls. This approach retains the flexibility of positioning while allowing for accurate line placement. Below, we break down the steps to implement this solution.

Step 1: Create the Custom Control

The custom control, which we will name LineConnectorControl, needs to establish links between two visual elements.

[[See Video to Reveal this Text or Code Snippet]]

In this control, we implement properties to retrieve the necessary coordinates and element details. The method UpdatePositions recalculates line positions whenever the connected elements change.

Step 2: Defining the Visual Style

Next, you'll need to define how the line will be drawn in Generic.xaml, a file that handles the styling of controls.

[[See Video to Reveal this Text or Code Snippet]]

This template tells WPF how to render the line, using properties from the LineConnectorControl for its coordinates and style.

Step 3: Using the Control in Your Layout

After defining the custom control, you can easily implement it in your application UI, like so:

[[See Video to Reveal this Text or Code Snippet]]

By specifying the parent, and the two controls to be connected, the line will automatically adjust its position whenever the size or position of the component changes.

Conclusion

Drawing diagonal lines in a WPF application can enhance the presentation of your interface, especially when linking sensors to their corresponding data displays. By creating a modular solution through a custom control, you not only solve the immediate problem but also lay the groundwork for future enhancements in your application. This approach keeps your controls flexible, allowing for responsive design while maintaining a clean MVVM architecture.

With your new LineConnectorControl, connector lines between controls will dynamically adjust, enhancing the interactivity and usability of your WPF application. Happy coding!