Qt开源作品16-通用无边框拖动拉伸Qt无边框拉伸Qt自定义控件大全+UI定制+输入法+视频监控+物联网-

一、前言

相信各位CS结构开发的程序员，多多少少都遇到过需要美化界面的事情，一般都不会采用系统的标题栏，这样就需要无边框标题栏窗体，默认的话无边框的标题栏都不支持拉伸和拖动的，毕竟去掉了标题栏则意味着失去了系统的窗体的属性，拉伸和拖动都需要自己写代码去实现，网上有很多类似的开源的方案，我也看过不少，总体来说复杂了些，对于初学者来说有可能看的云里雾里的，比如边框四周八个方位都可以自由拉伸这块，我的思路是针对设定的八个方位的区域进行识别鼠标是否按下，按下的哪个部位则执行什么拉伸策略，鼠标移到哪个位置则对应改变鼠标指针形状，更浅显易懂一些，至于拖动移动，还可以设置拖动的标题栏的高度等。

主要功能：

1. 可以指定需要无边框的widget
2. 边框四周八个方位都可以自由拉伸
3. 可设置对应位置的边距,以便识别更大区域
4. 可设置是否允许拖动
5. 可设置是否允许拉伸

二、代码思路

bool FramelessWidget::eventFilter(QObject *watched, QEvent *event) {     if (widget != 0 && watched == widget) {         if (event->type() == QEvent::Resize) {             //重新计算八个描点的区域,描点区域的作用还有就是计算鼠标坐标是否在某一个区域内             int width = widget->width();             int height = widget->height();              //左侧描点区域             rectLeft = QRect(0, padding, padding, height - padding * 2);             //上侧描点区域             rectTop = QRect(padding, 0, width - padding * 2, padding);             //右侧描点区域             rectRight = QRect(width - padding, padding, padding, height - padding * 2);             //下侧描点区域             rectBottom = QRect(padding, height - padding, width - padding * 2, padding);              //左上角描点区域             rectLeftTop = QRect(0, 0, padding, padding);             //右上角描点区域             rectRightTop = QRect(width - padding, 0, padding, padding);             //左下角描点区域             rectLeftBottom = QRect(0, height - padding, padding, padding);             //右下角描点区域             rectRightBottom = QRect(width - padding, height - padding, padding, padding);         } else if (event->type() == QEvent::HoverMove) {             //设置对应鼠标形状,这个必须放在这里而不是下面,因为可以在鼠标没有按下的时候识别             QHoverEvent *hoverEvent = (QHoverEvent *)event;             QPoint point = hoverEvent->pos();             if (resizeEnable) {                 if (rectLeft.contains(point)) {                     widget->setCursor(Qt::SizeHorCursor);                 } else if (rectRight.contains(point)) {                     widget->setCursor(Qt::SizeHorCursor);                 } else if (rectTop.contains(point)) {                     widget->setCursor(Qt::SizeVerCursor);                 } else if (rectBottom.contains(point)) {                     widget->setCursor(Qt::SizeVerCursor);                 } else if (rectLeftTop.contains(point)) {                     widget->setCursor(Qt::SizeFDiagCursor);                 } else if (rectRightTop.contains(point)) {                     widget->setCursor(Qt::SizeBDiagCursor);                 } else if (rectLeftBottom.contains(point)) {                     widget->setCursor(Qt::SizeBDiagCursor);                 } else if (rectRightBottom.contains(point)) {                     widget->setCursor(Qt::SizeFDiagCursor);                 } else {                     widget->setCursor(Qt::ArrowCursor);                 }             }              //根据当前鼠标位置,计算XY轴移动了多少             int offsetX = point.x() - lastPos.x();             int offsetY = point.y() - lastPos.y();              //根据按下处的位置判断是否是移动控件还是拉伸控件             if (moveEnable) {                 if (pressed) {                     widget->move(widget->x() + offsetX, widget->y() + offsetY);                 }             }              if (resizeEnable) {                 if (pressedLeft) {                     int resizeW = widget->width() - offsetX;                     if (widget->minimumWidth() <= resizeW) {                         widget->setGeometry(widget->x() + offsetX, rectY, resizeW, rectH);                     }                 } else if (pressedRight) {                     widget->setGeometry(rectX, rectY, rectW + offsetX, rectH);                 } else if (pressedTop) {                     int resizeH = widget->height() - offsetY;                     if (widget->minimumHeight() <= resizeH) {                         widget->setGeometry(rectX, widget->y() + offsetY, rectW, resizeH);                     }                 } else if (pressedBottom) {                     widget->setGeometry(rectX, rectY, rectW, rectH + offsetY);                 } else if (pressedLeftTop) {                     int resizeW = widget->width() - offsetX;                     int resizeH = widget->height() - offsetY;                     if (widget->minimumWidth() <= resizeW) {                         widget->setGeometry(widget->x() + offsetX, widget->y(), resizeW, resizeH);                     }                     if (widget->minimumHeight() <= resizeH) {                         widget->setGeometry(widget->x(), widget->y() + offsetY, resizeW, resizeH);                     }                 } else if (pressedRightTop) {                     int resizeW = rectW + offsetX;                     int resizeH = widget->height() - offsetY;                     if (widget->minimumHeight() <= resizeH) {                         widget->setGeometry(widget->x(), widget->y() + offsetY, resizeW, resizeH);                     }                 } else if (pressedLeftBottom) {                     int resizeW = widget->width() - offsetX;                     int resizeH = rectH + offsetY;                     if (widget->minimumWidth() <= resizeW) {                         widget->setGeometry(widget->x() + offsetX, widget->y(), resizeW, resizeH);                     }                     if (widget->minimumHeight() <= resizeH) {                         widget->setGeometry(widget->x(), widget->y(), resizeW, resizeH);                     }                 } else if (pressedRightBottom) {                     int resizeW = rectW + offsetX;                     int resizeH = rectH + offsetY;                     widget->setGeometry(widget->x(), widget->y(), resizeW, resizeH);                 }             }         } else if (event->type() == QEvent::MouseButtonPress) {             //记住当前控件坐标和宽高以及鼠标按下的坐标             QMouseEvent *mouseEvent = (QMouseEvent *)event;             rectX = widget->x();             rectY = widget->y();             rectW = widget->width();             rectH = widget->height();             lastPos = mouseEvent->pos();              //判断按下的手柄的区域位置             if (rectLeft.contains(lastPos)) {                 pressedLeft = true;             } else if (rectRight.contains(lastPos)) {                 pressedRight = true;             } else if (rectTop.contains(lastPos)) {                 pressedTop = true;             } else if (rectBottom.contains(lastPos)) {                 pressedBottom = true;             } else if (rectLeftTop.contains(lastPos)) {                 pressedLeftTop = true;             } else if (rectRightTop.contains(lastPos)) {                 pressedRightTop = true;             } else if (rectLeftBottom.contains(lastPos)) {                 pressedLeftBottom = true;             } else if (rectRightBottom.contains(lastPos)) {                 pressedRightBottom = true;             } else {                 pressed = true;             }         } else if (event->type() == QEvent::MouseMove) {             //改成用HoverMove识别         } else if (event->type() == QEvent::MouseButtonRelease) {             //恢复所有             pressed = false;             pressedLeft = false;             pressedRight = false;             pressedTop = false;             pressedBottom = false;             pressedLeftTop = false;             pressedRightTop = false;             pressedLeftBottom = false;             pressedRightBottom = false;             widget->setCursor(Qt::ArrowCursor);         }     }      return QObject::eventFilter(watched, event); } 

三、效果图

四、开源主页

以上作品完整源码下载都在开源主页，会持续不断更新作品数量和质量，欢迎各位关注。

1. 国内站点：https://gitee.com/feiyangqingyun/QWidgetDemo
2. 国际站点：https://github.com/feiyangqingyun/QWidgetDemo
3. 个人主页：https://blog.csdn.net/feiyangqingyun
4. 知乎主页：https://www.zhihu.com/people/feiyangqingyun/