目录

• 1、引言
• 2、实验代码
• 3、位置函数
• • 3.1 x()
  • 3.2 y()
  • 3.3 frame()
  • 3.4 pos()
  • 3.5 geometry()
  • 3.6 width()
  • 3.7 height()
  • 3.8 rect()
  • 3.9 size()

1、引言

QT有众多图形绘制函数，包括x()、y()、frame()、pos()、geometry()、width()、height()、rect()、size()，它们对屏幕坐标的捕获是有区别的。

2、实验代码

代码出自Qt5开发及实例（第3版）

geometry.h

#pragma once#include 
#include 
#include class geometry : public QDialog
{Q_OBJECT
public:geometry(QWidget *parent = nullptr);~geometry();void updateLabel();
private:QLabel* xLabel;QLabel* xValueLabel;QLabel* yLabel;QLabel* yValueLabel;QLabel* FrmLabel;QLabel* FrmValueLabel;QLabel* posLabel;QLabel* posValueLabel;QLabel* geoLabel;QLabel* geoValueLabel;QLabel* widthLabel;QLabel* widthValueLabel;QLabel* heightLabel;QLabel* heightValueLabel;QLabel* rectLabel;QLabel* rectValueLabel;QLabel* sizeLabel;QLabel* sizeValueLabel;QGridLayout* mainLayout;
protected:void moveEvent(QMoveEvent*);void resizeEvent(QResizeEvent *);
};

geometry.cpp

#include "geometry.h"geometry::geometry(QWidget *parent): QDialog(parent)
{setWindowTitle(tr("CH601"));xLabel = new QLabel(tr("x():"));xValueLabel = new QLabel;yLabel = new QLabel(tr("y():"));yValueLabel = new QLabel;FrmLabel = new QLabel(tr("Frame():"));FrmValueLabel = new QLabel;posLabel = new QLabel(tr("pos():"));posValueLabel = new QLabel;geoLabel = new QLabel(tr("geometry():"));geoValueLabel = new QLabel;widthLabel = new QLabel(tr("width():"));widthValueLabel = new QLabel;heightLabel = new QLabel(tr("height():"));heightValueLabel = new QLabel;rectLabel = new QLabel(tr("rect():"));rectValueLabel = new QLabel;sizeLabel = new QLabel(tr("size():"));sizeValueLabel = new QLabel;mainLayout = new QGridLayout(this);mainLayout->addWidget(xLabel,0,0);mainLayout->addWidget(xValueLabel, 0, 1);mainLayout->addWidget(yLabel, 1, 0);mainLayout->addWidget(yValueLabel, 1, 1);mainLayout->addWidget(FrmLabel, 2, 0);mainLayout->addWidget(FrmValueLabel, 2, 1);mainLayout->addWidget(posLabel, 3, 0);mainLayout->addWidget(posValueLabel, 3, 1);mainLayout->addWidget(geoLabel, 4, 0);mainLayout->addWidget(geoValueLabel, 4, 1);mainLayout->addWidget(widthLabel, 5, 0);mainLayout->addWidget(widthValueLabel, 5, 1);mainLayout->addWidget(heightLabel, 6, 0);mainLayout->addWidget(heightValueLabel, 6, 1);mainLayout->addWidget(rectLabel, 7, 0);mainLayout->addWidget(rectValueLabel, 7, 1);mainLayout->addWidget(sizeLabel, 8, 0);mainLayout->addWidget(sizeValueLabel, 8, 1);//updateLabel();
}
geometry::~geometry()
{}void geometry::updateLabel()
{QString xStr;xValueLabel->setText(xStr.setNum(x()));QString yStr;yValueLabel->setText(xStr.setNum(y()));QString frameStr;QString tempStr1, tempStr2, tempStr3, tempStr4;frameStr = tempStr1.setNum(frameGeometry().x()) + "," + tempStr2.setNum(frameGeometry().y())+ "," + tempStr3.setNum(frameGeometry().width()) + "," + tempStr4.setNum(frameGeometry().height());FrmValueLabel->setText(frameStr);QString positionStr;QString tempStr11, tempStr12;positionStr = tempStr11.setNum(pos().x()) + "," + tempStr12.setNum(pos().y());posValueLabel->setText(positionStr);QString geoStr;QString tempStr21, tempStr22, tempStr23, tempStr24;geoStr = tempStr21.setNum(geometry().x()) + "," + tempStr22.setNum(geometry().y())+ "," + tempStr23.setNum(geometry().width()) + "," + tempStr24.setNum(geometry().height());geoValueLabel->setText(geoStr);QString wStr, hStr;widthValueLabel->setText(wStr.setNum(width()));heightValueLabel->setText(wStr.setNum(height()));QString rectStr;QString tempSr31, tempStr32, tempStr33, tempStr34;rectStr = tempSr31.setNum(rect().x()) + "," + tempStr32.setNum(rect().y())+ ","+ tempStr33.setNum(/*rect().width()*/width()) + "," + tempStr34.setNum(/*rect().height()*/height());rectValueLabel->setText(rectStr);QString sizeStr;QString tempStr41, tempStr42;sizeStr = tempStr41.setNum(size().width()) + "," + tempStr42.setNum(size().height());sizeValueLabel->setText(sizeStr);
}void geometry::moveEvent(QMoveEvent*)
{updateLabel();
}void geometry::resizeEvent(QResizeEvent*)
{updateLabel();
}

实验结果：
结果1：

更改大小后得到结果2：

3、位置函数

3.1 x()

显示当前widget左上角坐标相对于主界面的x轴位置，x轴是向右计算。

3.2 y()

显示当前widget左上角坐标相对于主界面的y轴位置，y轴向下计算。

3.3 frame()

frame().x()和frame().y()和x()、y()相同，都表示左上角的坐标点，frame().width()表示当前整个程序框的宽度，frame().height()表示整个程序框的高度。

3.4 pos()

pos().x()和pos().y()都是相对于主界面来说的坐标点，与x()、y()相同。

3.5 geometry()

geometry().x()和geometry().y()返回当前主界面的坐标位置，同时geometry().width()和geometry().height()会返回主界面的大小，这里的Dialog属于是子窗口。

3.6 width()

width()返回当前窗口的宽度。

3.7 height()

height()返回当前窗口的高度。

3.8 rect()

rect().width()和rect().height()返回当前窗口的宽和高。

3.9 size()

size().width()和size().height()返回当前窗口的宽和高。