求阶乘
复制代码//计算阶乘2！
double factorial(double n) {
if (n == 0) {
return 0;
} else {
return n * (M_PI / 180);
}
}

复制代码void Qsort(int* a, int n)
{
assert(a);//断言防止越界
for (int i = 0; i < n-1; i++)
{
for (int j = 0; j < n - 1 - i; j++)
{
int tmp = a;
if (a > a)
{
a = a;
a = tmp;
}
}
}
}

int main()
{
int a[5] = { 5,6,2,9,0 };
Qsort(a, 5);
for (int i = 0; i < 5; i++)
{
printf("%d ", a);
}
return 0;
}原文章出处：原作者

1.Qpainter中setPen函数和setBrush函数在绘制图形时起到不同的作用。
setPen函数用于设置绘制图形边框的画笔，包括线条的颜色、宽度、样式等。通过setPen函数可以设置边框的样式，如实线、虚线、点线等，并可以指定颜色、宽度等属性。例子如下：
复制代码QPen pen(Qt::red, 2, Qt::DashDotLine);
painter.setPen(pen);
setBrush函数用于设置填充图形内部的画刷，包括填充的颜色、样式等。通过setBrush函数可以设置填充的样式，如纯色、渐变等，并可以指定颜色等属性。例子如下：
复制代码QBrush brush(Qt::blue, Qt::SolidPattern);
paint ..

C语言版：
复制代码void HSLtoRGB(float h, float s, float l, int* r, int* g, int* b) {
if (s == 0) {
// 灰色阶段
*r = *g = *b = l * 255;
} else {
float q = l < 0.5 ? l * (1 + s) : l + s - l * s;
float p = 2 * l - q;
float hk = h / 360.0;


float tr = hk + 1.0 / 3.0;
float tg = hk;
float tb = hk - 1.0 / 3.0;


// 确保值在0到1之间
if (tr < 0) tr += 1;
if (tr > 1) tr -= 1;
if (tg < 0) tg += 1;
if (tg > 1) tg -= 1;
if (tb < 0) tb += 1;
if (tb > 1) tb -= 1;


// ..

复制代码tableWidget->setColumnCount(25);
tableWidget->setRowCount(11);
tableWidget->horizontalHeader()->setVisible(false);
tableWidget->verticalHeader()->setVisible(false);

tableWidget->horizontalHeader()->setSectionResizeMode(QHeaderView::ResizeToContents);//ResizeToContents自适应宽度,Stretch各列平均分配列宽
tableWidget->verticalHeader()->setDefaultSectionSize(150);//设置默认行高30
tableWidget->horizontalHeader()->setDefaultSectionSize(50);
tableWidg ..

1.带绝对路径
复制代码QString video_File;
//mnt/sdcard/


//将路径写入video.txt
QString name_file="video.txt";
QFileInfo fileInfo;
QString Path;
QString filter="视频文件(*.mp4 *.wmv);;mp3文件(*.mp4);;;wmv文件(*.wmv);;所有文件(*.*)"; //文件过滤器
QStringList fileList=QFileDialog::getOpenFileNames(this,"选择视频文件","/home",filter);


if (fileList.count()<1)
return;


for (int i=0; i<fileList.count();i++)
{
video_File=QString("'% ..

文章来源：
将QQ中的图文聊天内容显示到Qt界面
复制代码#include <QMimeData>
#include <QClipboard>
#include <QDebug>
Widget::Widget(QWidget *parent)
: QWidget(parent)
, ui(new Ui::Widget)
{
ui->setupUi(this);
}

Widget::~Widget()
{
delete ui;
}


void Widget::on_pushButton_clicked()
{
const QClipboard *clipboard = QApplication::clipboard();
const QMimeData *mimeData = clipboard->mimeData();
if (mimeData->hasHtml()) {
QString html = mimeData->html();
html.repl ..

1.如何确定中心点：
复制代码QPainter painter(this);
painter.setRenderHints(QPainter::Antialiasing|QPainter::TextAntialiasing);
painter.translate(width()/2,height()/2);
int side =qMin(width(),height());
painter.scale(side/100.0,side/100.0);


draw_Yuan_2(painter);
painter.drawLine(0,0,50,50);
painter.drawText(-15,-13,25,25,Qt::AlignCenter,QString("<-这是中心点"));2

1.实现动画效果
复制代码void Widget::SetButtonStyle(QPushButton *button, QString imgsrc, int CutSec)
{//=========================Qss切割图片
int img_w=QPixmap(imgsrc).width();
int img_h=QPixmap(imgsrc).height();
int PicWidth = img_w/CutSec;
button->setFixedSize(PicWidth,img_h);
button->setStyleSheet(QString("QPushButton{border-width: 41px; border-image: url(%1) 0 0 0 %2 repeat repeat;border-width: 0px; border-radius: 0px;}")
.append("QPushButton::hover{border-image: url ..

Qt播放qrc中的mp3
复制代码player=new QMediaPlayer(this);
//如果是在qrc资源文件中用fromEncoded函数获取mp3地址（记得有前缀(/new或其他的)要加哦）
player->setMedia(QUrl::fromEncoded("qrc:/new/music/bgm_1.mp3"));
player->setVolume(50);
player->play();2.其他：来自网络Qt媒体播放之QMediaPlayer
复制代码QMediaPlayer *player = new QMediaPlayer();
/*从本地读取*/
player->setMedia(QUrl("F:/pianai.mp3"));
player->setMedia(QMediaContent(QUrl::fromLocalFile("F:/pianai. ..