Qt---实现在QLineEdit中输入密码时先显示明文，然后显示*号

//==>QPasswordLineEdit.h

#ifndef QPASSWORDLINEEDIT_H

#define QPASSWORDLINEEDIT_H

#include

class QPasswordLineEdit : public QLineEdit

{

Q_OBJECT

public:

QPasswordLineEdit(QWidget *parent,int timeout = 300);

~QPasswordLineEdit();

private slots:

void DisplayPasswordAfterEditSlot(int,int);

void DisplayPasswordSlot();

void GetRealTextSlot(const QString&);

public:

QString GetPassword() const;

void SetTimeout(int msec);

int GetTimeout() const;

private:

QString  GetMaskString();

private:

int  m_Timeout;

QString  m_LineEditText;

int  m_LastCharCount;

};

#endif // QPASSWORDLINEEDIT_H

/// ===> QPasswordLineEdit.cpp

#include "qpasswordlineedit.h"

#include

QPasswordLineEdit::QPasswordLineEdit(QWidget *parent,int timeout) : QLineEdit(parent)

{

m_Timeout = timeout;

m_LineEditText = "";

m_LastCharCount = 0;

connect(this,SIGNAL(cursorPositionChanged(int,int)),this,SLOT(DisplayPasswordAfterEditSlot(int,int)));

connect(this,SIGNAL(textEdited(const QString&)),this,SLOT(GetRealTextSlot(const QString&)));

}

QPasswordLineEdit::~QPasswordLineEdit()

{

}

void QPasswordLineEdit::DisplayPasswordAfterEditSlot(int oldPos,int newPos)

{

if(oldPos>=0 && newPos>=0 )

{

if(newPos>oldPos)

QTimer::singleShot(m_Timeout,this,SLOT(DisplayPasswordSlot()));

else

this->setCursorPosition(oldPos);

}

}

void QPasswordLineEdit::DisplayPasswordSlot()

{

this->setText(GetMaskString());

}

void QPasswordLineEdit::GetRealTextSlot(const QString& text)

{

if(text.count()>m_LastCharCount)

m_LineEditText.append(text.right(1));

else if(text.count()

m_LineEditText.remove(m_LineEditText.count()-1,1);

m_LastCharCount = m_LineEditText.count();

}

QString QPasswordLineEdit::GetPassword() const

{

return m_LineEditText;

}

void QPasswordLineEdit::SetTimeout(int msec)

{

m_Timeout = msec;

}

int QPasswordLineEdit::GetTimeout() const

{

return m_Timeout;

}

QString QPasswordLineEdit::GetMaskString()

{

QString mask = "";

int count = this->text().length();

if(count>0)

{

for(int i=0;i

mask += "*";

}

return mask;

}

通过GetPassword()可以获取当前的密码明文;