QT 定时自动关闭消息提示框简单实现
QT 定时自动关闭消息提示框简单实现
一、简述
记--使用Qt简单实现提示框简单，可定时自动关闭。
例子打包:外链:https://wwm.lanzouv.com/b0cau3tid 密码:g3ob
二、效果
三、工程结构
UI界面
四、源文件
NoticeWidget.pro文件
QT += core guigreaterThan(QT_MAJOR_VERSION, 4): QT += widgetsTARGET = Notice
TEMPLATE = appSOURCES += main.cpp\mainwindow.cpp \noticewidget.cppHEADERS += mainwindow.h \noticewidget.hFORMS += mainwindow.uimainwindow.h文件
#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include
#include "noticewidget.h"namespace Ui {
class MainWindow;
}class MainWindow : public QMainWindow
{Q_OBJECTpublic:explicit MainWindow(QWidget *parent = 0);~MainWindow();private slots:void on_pushButtonShowNotice_clicked();private:Ui::MainWindow *ui;NoticeWidget noticeWin;
};#endif // MAINWINDOW_H
mainwindow.cpp文件
#include "mainwindow.h"
#include "ui_mainwindow.h"MainWindow::MainWindow(QWidget *parent) :QMainWindow(parent),ui(new Ui::MainWindow)
{ui->setupUi(this);setWindowTitle("定时自动关闭消息提示框");ui->plainTextEditMsg->setPlainText("定时自动关闭消息提示框测试，简单测试例子");
}MainWindow::~MainWindow()
{delete ui;
}void MainWindow::on_pushButtonShowNotice_clicked()
{ noticeWin.Notice(this, ui->plainTextEditMsg->toPlainText(), 20000);
}
noticewidget.h文件
#ifndef _NoticeWidget_H_
#define _NoticeWidget_H_#include
#include
#include //定时器间隔，单位ms
#define TIMER_INTERVAL_MS 50//默认提示时间1s
#define NOTICE_DEF_DELAY_CNT (1000/TIMER_INTERVAL_MS)//透明度最大值255，也就是不透明
#define TRANSPARENT_MAX_VAL 255//透明度递减值
#define TRANSPARENT_CUT_VAL (TRANSPARENT_MAX_VAL/NOTICE_DEF_DELAY_CNT + 1)//大小比例
#define SIZE_SCALE 0.8//高度补偿
#define PATCH_HEIGHT 10//样式，字体颜色：白色；圆角；背景色透明度
#define STYLE_SHEET "color:white;border-radius:8px;background-color:rgba(80, 80, 80, %1);"class NoticeWidget :public QLabel
{Q_OBJECTpublic:void Notice(QWidget *parent, const QString &msg, const int delay_ms = 2000);public:explicit NoticeWidget(QWidget *parent = 0);~NoticeWidget();private:void SetMesseage(const QString &msg, int delay_ms);void ChangeSize();public slots:void OnTimerTimeout();private:QWidget *mParentPtr;QTimer *mTimerPtr;int mTimerCount;int mBaseWidth; //按一行时算的宽度int mBaseHeight; //一行高度int mMinHeight; //最小高度int mTransparentVal;//透明度0~255，值越小越透明QList mListLinesLen;
};#endif // _NoticeWidget_H_
noticewidget.cpp文件
#include "noticewidget.h"NoticeWidget::NoticeWidget(QWidget *parent): mParentPtr(parent), mTimerPtr(nullptr), mTimerCount(NOTICE_DEF_DELAY_CNT), mBaseWidth(0), mBaseHeight(0), mMinHeight(0), mTransparentVal(TRANSPARENT_MAX_VAL){//文字居中setAlignment(Qt::AlignCenter);//定时器，定时消失mTimerPtr = new QTimer();connect(mTimerPtr, SIGNAL(timeout()), this, SLOT(OnTimerTimeout()), Qt::UniqueConnection);
}NoticeWidget::~NoticeWidget()
{if (mTimerPtr->isActive()) {mTimerPtr->stop();}delete mTimerPtr;deleteLater();
}void NoticeWidget::OnTimerTimeout()
{--mTimerCount;if (0 < mTimerCount) {//重新定位(窗口大小和位置可能变化)if (nullptr != mParentPtr) {QPoint pt((mParentPtr->width() - width()) >> 1, (mParentPtr->height() - height()) >> 1);if (pos() != pt) {//父窗口位置变化ChangeSize();move(pt);}}//最后1s开始渐变消失if (mTimerCount <= NOTICE_DEF_DELAY_CNT && 0 < mTransparentVal) {mTransparentVal -= TRANSPARENT_CUT_VAL;if (0 > mTransparentVal) {mTransparentVal = 0;}//控制透明度setStyleSheet(QString(STYLE_SHEET).arg(mTransparentVal));}} else {//显示结束mTimerPtr->stop();setVisible(false); }
}//设置要显示的消息
void NoticeWidget::SetMesseage(const QString &msg, int delay_ms)
{QStringList strList = msg.split("\n");QFontMetrics fontMetrics(font());mListLinesLen.clear();int tmpW = 0;int maxLineLen = 1; //最长那一行的长度foreach (QString s, strList) {tmpW = fontMetrics.width(s);mListLinesLen.append(tmpW);if (maxLineLen < tmpW) {maxLineLen = tmpW;}}mParentPtr = parentWidget();mBaseWidth = fontMetrics.width(msg);mBaseHeight = fontMetrics.lineSpacing() + PATCH_HEIGHT;mMinHeight = (mBaseWidth * mBaseHeight)/maxLineLen + 1;//面积除以最长的宽就是最小的高//设置宽高ChangeSize();//换行setWordWrap(true);//设置显示内容setText(msg);//居中if (nullptr != mParentPtr) {move((mParentPtr->width() - width()) >> 1, (mParentPtr->height() - height()) >> 1);}setVisible(true);//显示setStyleSheet(QString(STYLE_SHEET).arg(TRANSPARENT_MAX_VAL));//设置样式，不透明mTimerCount = delay_ms/TIMER_INTERVAL_MS + 1;//延时计数计算mTransparentVal = TRANSPARENT_MAX_VAL;
}//跟随父窗口大小变化
void NoticeWidget::ChangeSize()
{if (nullptr != mParentPtr) {double wd = mParentPtr->width() * SIZE_SCALE;//宽度占父窗口的80%//提示内容多少决定提示框面积，长方形面积s=mBaseHeight*mBaseWidth//面积s固定，当mBaseWidth跟随窗体宽度变大而增大，那么mBaseHeight应当变小，才维持s固定int newH = (mBaseHeight*mBaseWidth)/wd + PATCH_HEIGHT;if (newH < (mMinHeight + mBaseHeight)) {//设定最小高度newH = mMinHeight + mBaseHeight;} else {foreach (int lineLen, mListLinesLen) {if (lineLen > wd) {//某一行长度大于当前宽度就会发生折行，高度需要增加newH += mBaseHeight;}}}setFixedSize((int)wd, newH);}
}//显示消息，可通过设置delay_ms=0来立即关闭显示
void NoticeWidget::Notice(QWidget *parent, const QString &msg, const int delay_ms)
{if (mTimerPtr->isActive()) {mTimerPtr->stop();setVisible(false);}//消息为空直接返回if (msg.isEmpty() || 0 >= delay_ms) {return;}setParent(parent);SetMesseage(msg, delay_ms);mTimerPtr->start(TIMER_INTERVAL_MS);//开始计数
}main.cpp文件
#include "mainwindow.h"
#include int main(int argc, char *argv[])
{QApplication a(argc, argv);MainWindow w;w.show();return a.exec();
}
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