Qt之布局管理——（1）基本布局管理

Qt提供的布局类以及他们之间的继承关系（如下图）：

常用到的布局类有：QHBoxLayout、QVBoxLayout、QGridLayout三种，分别是水平排列布局、垂直排列布局、表格排列布局。

常用的方法有addWidget()和addLayout()。addWidget()用于在布局中插入控件，addLayout()用于在布局中插入子布局。

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在布局管理中还常用到setMargin()用于设定边距，setSpacing()用于设定控件间距。

setColumnStretch()用于设置列的占空比。

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示例：实现如下图的布局

basiclayout.h

#ifndef BASICLAYOUT_H
#define BASICLAYOUT_H

#include <QtGui>



class BasicLayout : public QDialog
{
	Q_OBJECT

public:
	BasicLayout(QWidget *parent = 0, Qt::WFlags flags = 0);
	~BasicLayout();

private:
	QLabel *labUser;
	QLabel *labName;
	QLabel *labSex;
	QLabel *labDepartment;
	QLabel *labAge;
	QLabel *labRemark;
	QLineEdit *edtUser;
	QLineEdit *edtName;
	QComboBox *cbbSex;
	QTextEdit *edtDepartment;
	QLineEdit *edtAge;

	QLabel *labHead;
	QLabel *labIcon;
	QLabel *labIndividual;
	QPushButton *btnChange;
	QTextEdit *edtIndividual;

	QPushButton *btnOk;
	QPushButton *btnCancel;
};

#endif // BASICLAYOUT_H

basiclayout.cpp

#include "basiclayout.h"

BasicLayout::BasicLayout(QWidget *parent, Qt::WFlags flags)
	: QDialog(parent, flags)
{
	setWindowTitle(tr("User Infomation"));
	
	//Left Loyout:
	labUser = new QLabel(tr("User Name:"));
	labName = new QLabel(tr("Name;"));
	labSex = new QLabel(tr("Sex:"));
	labDepartment = new QLabel(tr("Department:"));
	labAge = new QLabel(tr("Age:"));
	labRemark = new QLabel(tr("Remark:"));
	labRemark->setFrameStyle(QFrame::Panel|QFrame::Sunken);
	edtUser = new QLineEdit;
	edtName = new QLineEdit;
	cbbSex = new QComboBox;
	cbbSex->insertItem(0,tr("Female"));
	cbbSex->insertItem(1,tr("Male"));
	edtDepartment = new QTextEdit;
	edtAge = new QLineEdit;

	QGridLayout *leftLayou = new QGridLayout;
	int col_Lab = 0;
	int col_Content = 1;
	leftLayou->addWidget(labUser,0,col_Lab);
	leftLayou->addWidget(edtUser,0,col_Content);
	leftLayou->addWidget(labName,1,col_Lab);
	leftLayou->addWidget(edtName,1,col_Content);
	leftLayou->addWidget(labSex,2,col_Lab);
	leftLayou->addWidget(cbbSex,2,col_Content);
	leftLayou->addWidget(labDepartment,3,col_Lab);
	leftLayou->addWidget(edtDepartment,3,col_Content);
	leftLayou->addWidget(labAge,4,col_Lab);
	leftLayou->addWidget(edtAge,4,col_Content);
	leftLayou->addWidget(labRemark,5,col_Lab,1,2);
	leftLayou->setColumnStretch(0,1);	//设置两列分别占有空间的比例
	leftLayou->setColumnStretch(1,3);

	//Right Layout:
	labHead = new QLabel(tr("Head:"));
	labIcon = new QLabel;
	QPixmap m_icon("head.gif");
	labIcon->resize(m_icon.width(),m_icon.height());
	labIcon->setPixmap(m_icon);
	btnChange = new QPushButton(tr("Change"));
	QHBoxLayout *headLayout = new QHBoxLayout;
	headLayout->addWidget(labHead);
	headLayout->addWidget(labIcon);
	headLayout->addWidget(btnChange);
	headLayout->setSpacing(20);	//控件间距为20像素
	labIndividual = new QLabel(tr("Individual:"));
	edtIndividual = new QTextEdit;
	QVBoxLayout *rightLayout = new QVBoxLayout;
	rightLayout->addLayout(headLayout);
	rightLayout->addWidget(labIndividual);
	rightLayout->addWidget(edtIndividual);
	rightLayout->setMargin(10);

	//Bottom Layout:
	btnOk = new QPushButton(tr("Ok"));
	btnCancel = new QPushButton(tr("Cancel"));
	QHBoxLayout *bottomLayout = new QHBoxLayout;
	bottomLayout->addStretch();	//添加一个占位符
	bottomLayout->addWidget(btnOk);
	bottomLayout->addWidget(btnCancel);
	bottomLayout->setSpacing(10);

	//Main Layout:
	QGridLayout *mainLayout = new QGridLayout(this);
	mainLayout->addLayout(leftLayou,0,0);
	mainLayout->addLayout(rightLayout,0,1);
	mainLayout->addLayout(bottomLayout,1,0,1,2);
	mainLayout->setMargin(15);
	mainLayout->setSpacing(10);
	mainLayout->setSizeConstraint(QLayout::SetFixedSize);	//设置对话框大小固定，不允许用户改变

}

BasicLayout::~BasicLayout()
{

}

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setFrameStyle()是QFrame的方法，参数以或的方式设定控件的风格，参数1（QFrame::Shape）用于设定控件的形状，参数2（QFrame::Shadow）用于设定控件俺的阴影。

形状有：NoFrame、Panel、Box、HLine、VLine、WinPanel 6种；阴影有：Plain、Raised、Sunken三种。

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