文章目錄：

 設(shè)置按鈕背景色

ui->pushButton->setStyleSheet("background-color:green");
  設(shè)置按鈕字體顏色
ui->pushButton->setStyleSheet("color:red");
ui->pushButton->setStyleSheet("QPushButton{font:bold 16px;color:red}");
  設(shè)置按鈕背景圖片
ui->pushButton->setIconSize(QSize(ui->pushButton->width(),ui->pushButton->height())); 
ui->pushButton->setIcon(QIcon(QPixmap(":/file/image/map.png")));

2,QLineEdit的使用

 設(shè)置值
ui->lineEdit->setText("hello");
獲取值
qDebug() << ui->lineEdit->text();
設(shè)置密碼模式
ui->lineEdit->setEchoMode(QLineEdit::Password);
輸入的密碼自動變成圓形圖案
 ui->lineEdit->setEchoMode(QLineEdit::PasswordEchoOnEdit);
輸入的密碼在失焦后變成圓形圖案
ui->lineEdit->setPlaceholderText("input text:"); 提示輸入
ui->lineEdit->setGeometry(50,50,100,100);  //設(shè)置位置大小

3,QTextEdit的使用

 設(shè)置值
ui->textEdit->setText("hello");
ui->textEdit->append(“hello”);  //追加
  獲取值
qDebug() << ui->textEdit->toPlainText();

4,RadioButton的使用

選中
ui->radioButton->setCheckable(true);
ui->radioButton->setChecked(true);
 取消選中
ui->radioButton->setCheckable(false);
Radio button特性是多個只能選中一個

5,CheckBox的使用

 選中
ui->checkBox->setCheckable(true); 
ui->checkBox->setChecked(true); 
ui->checkBox_2->setChecked(true);
取消選中
ui->checkBox->setChecked(false);
 查詢選中狀態(tài)
qDebug() << ui->checkBox_2->isChecked();
Check Box特性是同時可以選中多個

6,TableWidget的使用

設(shè)置表格行列數(shù)
ui->tableWidget->setColumnCount(4); 
ui->tableWidget->setRowCount(3);
 往表格中添加元素
QTableWidgetItem *itm = new QTableWidgetItem(tr("a")); 
ui->tableWidget->setItem(1,1,itm);
itm->setTextAlignment(Qt::AlignLeft);
QLabel *label = new QLabel();
 label->setPixmap(QPixmap(":/file/image/map.png").scaled(40,50)); ui->tableWidget->setCellWidget(0,0,label);

7,QComboBox的使用

 QComboBox *box = new QComboBox(); 
box->addItem("male");
box->addItem("female"); 
ui->tableWidget->setCellWidget(0,2,box);

 獲取條目值
qDebug() << box->currentText();
qDebug() << box->itemText(1);

8,QDataTime的使用

QDateTimeEdit *time = new QDateTimeEdit(); 
time->setDateTime(QDateTime::currentDateTime()); 
time->setDisplayFormat("dd/M/yyyy"); 
time->setCalendarPopup(true); //鼠標點上去,，自動彈出日歷
ui->tableWidget->setCellWidget(2,0,time);

9,Spin Box的使用

 創(chuàng)建,、設(shè)置范圍,、設(shè)置步進值
ui->spinBox->setRange(1,100); 
ui->spinBox->setSingleStep(10); 
ui->spinBox->setValue(20);
 獲取當前值
qDebug() << ui->spinBox->value();

10,LCD Number的使用

 設(shè)置顯示數(shù)值位數(shù),、設(shè)置值,、設(shè)置顯示模式
ui->lcdNumber->setDigitCount(10); 
ui->lcdNumber->setHexMode(); 
ui->lcdNumber->display(1000); 

11,Progress Bar的使用

  設(shè)置范圍,、設(shè)置顯示進度值
 ui->progressBar->setRange(1,100); 
 ui->progressBar->setValue(60);

12,Label的使用

 創(chuàng)建、設(shè)置背景色,、設(shè)置標簽文字,、獲取標簽
ui->label->setStyleSheet("background-color:red"); 
ui->label->setText("hello"); 
qDebug() << ui->label->text();

13,QTime時鐘類的使用

A QTime object contains a clock time, i.e. the number of hours, minutes, seconds, and milliseconds since midnight 
QTime time = QTime::currentTime(); 
qDebug() << time.hour(); 
QString text = time.toString("hh:mm"); 
qDebug() << text;

14,QToolBox工具盒類的使用

 QToolBox, QToolButton 
ui->toolButton->setText("小明"); 
ui->toolButton->setIcon(QPixmap(":/file/images/1.png"));
ui->toolButton->setIconSize(QPixmap(":/file/images/1.png").size()); 
ui->toolButton->setToolButtonStyle(Qt::ToolButtonTextBesideIcon); 
ui->toolButton->setAutoRaise(true); 

15,QPalette調(diào)色板類

  例: 設(shè)置背景圖片
setAutoFillBackground(true); 
QPalette pal;
pal.setBrush(QPalette::Background,QBrush(QPixmap(":/1.jpg"))); 
setPalette(pal);

使用樣式表（setStyleSheet函數(shù)）比調(diào)色板更加可靠

16,分割窗口Qsplitter類

split = new QSplitter(); 
edit1 = new QTextEdit(); 
edit2 = new QTextEdit(); 
edit3 = new QTextEdit();
split->addWidget(edit1);
split->addWidget(edit2);
split->addWidget(edit3);
split->setWindowTitle("split window");
split->show();

17,QListWidget類的使用

18,基本的布局類:

(1)水平布局

btn1 = new QPushButton(tr("C")); 
btn2 = new QPushButton(tr("C++"));
  btn3 = new QPushButton(tr("Java")); QHBoxLayout *layout = new QHBoxLayout(); 
layout->addWidget(btn1); 
layout->addWidget(btn2); 
layout->addWidget(btn3); setLayout(layout);

(2)垂直布局
btn1 = new QPushButton(tr("C")); 
btn2 = new QPushButton(tr("C++"));
  btn3 = new QPushButton(tr("Java")); QVBoxLayout *layout = new QVBoxLayout();
layout->addWidget(btn1); 
layout->addWidget(btn2); 
layout->addWidget(btn3); setLayout(layout);

(3)柵格布局
lab1 = new QLabel(tr("姓名")); 
lab2 = new QLabel(tr("性別")); 
line1 = new QLineEdit();
box = new QComboBox(); 
box->addItem("男"); 
box->addItem("女"); 
lab3 = new QLabel(tr("備注:以上信息請認真填寫"));
  lab4 = new QLabel(tr("個人簡介")); 
edit = new QTextEdit(); 
QGridLayout *layout = new QGridLayout(); 
layout->addWidget(lab1, 0, 0);
layout->addWidget(line1, 0, 1);
layout->addWidget(lab2, 1, 0); 
layout->addWidget(box, 1, 1);
layout->addWidget(lab4, 2, 0);
layout->addWidget(edit, 2, 1); layout->addWidget(lab3, 3, 0, 1, 2);
  setLayout(layout);

19,標準文件對話框

  QFileDialog
QString s = QFileDialog::getOpenFileName
(this, "open file dialog", "/", 
"C++ files (*.cpp);;C files (*.c);;Head files (*.h);;all files(*.*)");
ui->lineEdit->setText(s);

20,標準顏色對話框

 QColorDialog
QColor color = QColorDialog::getColor (Qt::blue); if(color.isValid()) 
{ 
ui->frame->setAutoFillBackground(true); 
ui->frame->setPalette(QPalette(color)); 
}

21,標準字體對話框

QFontDialog
bool ok;                  
QFont font = QFontDialog::getFont( &ok );      
if( ok )     
{    
fontLineEdit->setFont( font );    
}

22,標準輸入對話框

QInputDialog
bool ok; 
QString name = QInputDialog::getText(this, tr("User Name"), tr("Please input new name:"), QLineEdit::Normal, ui->nameLabel->text(),&ok);
if(ok && !name.isEmpty()) 
ui->nameLabel->setText(name);
QStringList list; 
list << tr("male") << tr("female"); 
bool ok; 
QString sex = QInputDialog::getItem(this,tr(“Sex”), tr(“Please selectsex:”),list,0,false,&ok);        //false參數(shù)表示對list不能作修改
if (ok) 
ui->nameLabel->setText(sex);

23,消息對話框

QMessageBox
switch(QMessageBox::question(this,"Question",tr("It's end of document,search from begin?"),
    QMessageBox::Ok|QMessageBox::Cancel,QMessageBox::Ok))
   {
  case QMessageBox::Ok:
    label->setText(" Question button / Ok ");
    break;
    case QMessageBox::Cancel:
    label->setText(" Question button / Cancel ");
    break;
    default:
    break;
    }

QMessageBox::information(this,"Information",tr("anything you want tell user"));


 switch(QMessageBox::warning(this,"Warning",tr("Save changes to document?"),
   QMessageBox::Save|QMessageBox::Discard|QMessageBox::Cancel,QMessageBox::Save))
    {
    case QMessageBox::Save:
    label->setText(" Warning button / Save ");
    break;
    case QMessageBox::Discard:
    label->setText(" Warning button / Discard ");
    break;
    case QMessageBox::Cancel:
    label->setText(" Warning button / Cancel ");
    break;
    default:
    break;
    }

24,打開文件操作

25,保存文件代碼

26,二維圖形

  Qt的二維圖形引擎是基于Qpainter類，QPainter既可以繪制幾何形狀（點,、線,、矩形、橢圓,、弧形,、多邊形等），也可以繪制像素映射,、圖像,、文字
  重新實現(xiàn)QWidget::paintEvent()可用于定制窗口部件
  使用Qpainter的draw函數(shù)，可以繪制各種各樣的形狀,，繪制的效果取決于Qpainter的設(shè)置,。三個主要的設(shè)置是畫筆、畫刷和字體

利用Qpainter繪制各種圖形

畫筆QPen類
The QPen class defines how a QPainter should draw lines and outlines of shapes,。
A pen has a style(), width(), brush(), capStyle() and joinStyle().

畫刷類QBrush
The QBrush class defines the fill pattern of shapes drawn by QPainter.
A brush has a style, a color, a gradient and a texture.

重寫paintEvent函數(shù)
當調(diào)用update函數(shù)時,，paintEvent函數(shù)會被自動調(diào)用

oid Dialog::paintEvent(QPaintEvent *)
 { 
QPainter painter(this);
painter.setPen(Qt::blue); 
painter.setFont(QFont("Arial", 30));
  painter.drawText(rect(), Qt::AlignCenter, "Qt");painter.drawLine(110,20,30,40);painter.drawPixmap(45,69,QPixmap(":/file/image/4.png"));
 }

27,背景圖片設(shè)置

27,打開文件

  Qfile  open方法

讀寫文本文件

文件讀寫一般通過QTextStream （文本方式）或者QDataStream（二進制方式）進行
寫文件
QFile file("test.txt"); 
/*如果文件不存在，會自動創(chuàng)建*/ 
if (file.open(QIODevice::WriteOnly | QIODevice::Text)) 
{
QTextStream out(&file); 
out << "hello world" << endl << "nihao" << endl;
  }
else 
{
QMessageBox::information(this, "msg", "file not found");
}

使用QDataStream進行文件讀寫