在数字时代，图像标注功能在许多应用场景中都显得尤为重要。例如，地图应用允许用户在地图上绘制方向，保险公司可能需要在车辆照片上标注受损部位。实现这些功能，需要对交互式界面设计有一定的了解。本文将介绍如何使用JavaScript和CSS在网页上实现图像标注功能，并将标注结果与背景图像相结合。
在开始之前，需要熟悉墨迹草图控件（ink sketch control）。如果还不熟悉，请先阅读相关文档。
首先，需要在表单中添加一个文本字段，命名为“PictureURL”，并将其放置在表单上。这个字段将包含背景图片的URL。注意，可以将图片上传到SharePoint站点的文档库中，然后将链接粘贴到这个字段中。
接下来，需要在表单中添加以下JavaScript代码：
var url = fd.field('PictureURL').value();
$('.sketch').css('background-image', 'url("' + url + '")');
这段代码的作用是获取用户输入的图片URL，并将其设置为墨迹草图控件的背景图片。
然后，需要为墨迹草图控件添加CSS类“sketch”。
接下来，需要设置墨迹草图控件的高度和宽度属性，使其与图片的尺寸相匹配。设置完成后，保存表单。
现在，用户需要在“PictureURL”字段中输入指向图片文件的URL，保存表单，重新加载，然后他们将看到带有背景图片的墨迹草图。
通过上述步骤，可以在网页上实现一个交互式的图像标注功能。用户可以轻松地在图片上进行标注，而不会直接修改图片文件。这种功能在许多应用场景中都非常有用，如地图导航、保险理赔等。
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<title>Image Annotation Feature</title>
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<meta name="description" content="Learn how to implement image annotation features on web pages using JavaScript and CSS.">
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<h1>Image Annotation Feature</h1>
<p>In the digital age, image annotation features are crucial in many applications. For example, map applications allow users to draw directions on a map, and insurance companies may need to mark damaged parts on vehicle photos. To implement these features, you need to have a good understanding of interactive interface design. This article will introduce how to use JavaScript and CSS to implement image annotation features on web pages and combine the annotation results with background images.</p>
<h2>Preparation Work</h2>
<p>Before you start, you need to be familiar with the ink sketch control. If you are not familiar with it, please read the relevant documentation first.</p>
<h2>Setting Up the Ink Sketch Control</h2>
<p>First, you need to add a text field to the form, name it "PictureURL", and place it on the form. This field will contain the URL of the background picture for the ink sketch. Note that you can upload the picture to a document library on your SharePoint site and then just paste the link into this field.</p>
<h2>Adding JavaScript Code</h2>
<p>Next, you need to add the following JavaScript code to the form:</p>
<code>
var url = fd.field('PictureURL').value();
$('.sketch').css('background-image', 'url("' + url + '")');
</code>
<p>This code gets the picture URL entered by the user and sets it as the background picture of the ink sketch control.</p>
<h2>Adding CSS Class</h2>
<p>Then, you need to add the CSS class "sketch" to the ink sketch control.</p>
<h2>Setting Control Attributes</h2>
<p>Next, you need to set the height and width attributes of the ink sketch control to match the size of the picture. After setting, save the form.</p>
<h2>User Operation</h2>
<p>Now, the user needs to enter the URL of the picture file into the "PictureURL" field, save the form, reload it, and then they will see the ink sketch with the picture as the background.</p>
<h2>Summary</h2>
<p>By following the above steps, you can implement an interactive image annotation feature on the web page. Users can easily annotate on the picture without directly modifying the picture file. This feature is very useful in many application scenarios, such as map navigation, insurance claims, etc.</p>
<h2>Further Reading</h2>
<p>If you are interested in how to further optimize the user interface and improve the user experience, you can read more articles on interactive design and front-end development.</p>
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