利用CRectTracker画可调整矩形
![preview](https://csdnimg.cn/release/downloadcmsfe/public/img/white-bg.ca8570fa.png)
![preview-icon](https://csdnimg.cn/release/downloadcmsfe/public/img/scale.ab9e0183.png)
![star](https://csdnimg.cn/release/downloadcmsfe/public/img/star.98a08eaa.png)
在Windows编程中,MFC(Microsoft Foundation Classes)库提供了一个强大的工具——`CRectTracker`,用于绘制并交互式地调整矩形。本篇将详细讲解如何利用`CRectTracker`来实现用户可调整的矩形,以及相关的重要知识点。 `CRectTracker`类是MFC提供的一个辅助类,它的主要功能是在窗口上绘制一个可以拖动边框的矩形,并根据用户的鼠标操作实时更新矩形的大小和位置。这个特性在需要用户自定义选择区域或者调整图形大小的场景中非常有用。 1. **创建CRectTracker对象**: 在使用`CRectTracker`前,你需要创建一个`CRectTracker`对象。你可以初始化这个对象,指定一个初始的矩形区域,通常是一个`CRect`对象。例如: ```cpp CRect rect(0, 0, 100, 100); CRectTracker tracker(rect); ``` 2. **设置样式**: `CRectTracker`提供了多种样式,可以设置矩形的边框类型、是否显示中心点等。例如,你可以通过`SetHandleSize()`来设置调整手柄的大小,`SetStyle()`来设置矩形的风格,比如单线、双线或者虚线。 3. **绘制矩形**: 在`OnDraw`或类似函数中,你需要调用`CRectTracker::DrawTrackerRect()`来绘制矩形及其调整手柄。这个函数会根据当前的样式和矩形位置在设备上下文中绘制矩形。 4. **处理鼠标消息**: 当用户与矩形交互时,你需要捕获并处理鼠标消息,如`WM_LBUTTONDOWN`、`WM_LBUTTONUP`和`WM_MOUSEMOVE`。在这些消息的处理函数中,你可以调用`CRectTracker::TrackRect()`来响应用户的拖动操作。此函数会更新矩形的位置和大小,并返回新的矩形。 5. **更新矩形**: 调用`CRectTracker::m_rect`获取更新后的矩形位置和大小,然后根据需要更新你的应用程序状态。例如,你可能需要更新显示在矩形内的内容或者保存新的矩形边界。 6. **处理异常情况**: 当用户尝试将矩形调整到不合法的大小(如宽度小于0或高度小于0)时,你需要进行适当的错误检查并处理。可以设置一个最小尺寸限制,确保用户不能缩放至负值。 7. **优化用户体验**: 为了提供更好的用户体验,你可能还需要处理其他细节,如绘制矩形时考虑反锯齿效果,或者添加视觉反馈,如高亮显示正在拖动的边框。 8. **保存和恢复状态**: 如果你的应用程序需要在多次运行之间保持矩形的状态,你需要在关闭时保存`CRectTracker`的矩形信息(通常是`CRectTracker::m_rect`),并在下次启动时恢复它。 通过以上步骤,你可以利用MFC的`CRectTracker`轻松实现用户可调整的矩形。这个功能在图像编辑、绘图应用或任何需要用户定义区域的程序中都十分实用。记住,良好的设计应该考虑到各种用户交互可能性,使调整过程流畅且直观。在实际开发中,根据具体需求对`CRectTracker`进行适当的扩展和定制,可以进一步提升应用的易用性。
![application/x-rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![7z](https://img-home.csdnimg.cn/images/20210720083312.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![7z](https://img-home.csdnimg.cn/images/20210720083312.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![7z](https://img-home.csdnimg.cn/images/20210720083312.png)
![application/x-rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![package](https://csdnimg.cn/release/downloadcmsfe/public/img/package.f3fc750b.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/EXE.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/TXT.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
- 1
![avatar](https://profile-avatar.csdnimg.cn/94764bd0d3484ca7a83e0179ea0d7e1b_qzhforthelife.jpg!1)
- 粉丝: 9
- 资源: 15
我的内容管理 展开
我的资源 快来上传第一个资源
我的收益
登录查看自己的收益我的积分 登录查看自己的积分
我的C币 登录后查看C币余额
我的收藏
我的下载
下载帮助
![voice](https://csdnimg.cn/release/downloadcmsfe/public/img/voice.245cc511.png)
![center-task](https://csdnimg.cn/release/downloadcmsfe/public/img/center-task.c2eda91a.png)
最新资源
- 打包和分发Rust工具.pdf
- SQL中的CREATE LOGFILE GROUP 语句.pdf
- C语言-leetcode题解之第172题阶乘后的零.zip
- C语言-leetcode题解之第171题Excel列表序号.zip
- C语言-leetcode题解之第169题多数元素.zip
- ocr-图像识别资源ocr-图像识别资源
- 图像识别:基于Resnet50 + VGG16模型融合的人体细胞癌症分类模型实现-图像识别资源
- C语言-leetcode题解之第168题Excel列表名称.zip
- C语言-leetcode题解之第167题两数之和II-输入有序数组.zip
- C语言-leetcode题解之第166题分数到小数.zip
![feedback](https://img-home.csdnimg.cn/images/20220527035711.png)
![feedback-tip](https://img-home.csdnimg.cn/images/20220527035111.png)
![dialog-icon](https://csdnimg.cn/release/downloadcmsfe/public/img/green-success.6a4acb44.png)
- 1
- 2
- 3
- 4
- 5
前往页