QLineEdit将数字转化为字符串，对单个字符的修改

第一次写博客，记录生活点滴；


 实现qlineedit，获取文本中的特定字符，进行操作；

光标的移动；
获取返回的字符；

替换原有字符；

由于比较简单，直接上代码：#include "widget.h"
#include "ui_widget.h"
#include <QKeyEvent>
#include <QDebug>

Widget::Widget(QWidget *parent) :
QWidget(parent),
ui(new Ui::Widget)
{
ui->setupUi(this);
test_num = 1234.56780012000;
ui->lineEdit->setText(QString::number(test_num,'f',11));
length = -1;
//ui->lineEdit->setReadOnly(true);
}

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

void Widget::keyPressEvent(QKeyEvent *event)
{
int num = 0;
switch(event->key())
{

case Qt::Key_F4:
if(ui->lineEdit->selectedText()<"0" ||ui->lineEdit->selectedText()>"9" )
{
break;
}
num = ui->lineEdit->selectedText().toInt();
num-- ;
if(num < 0)
{
num = 9;
}
ui->lineEdit->insert(QString::number(num));
ui->lineEdit->cursorBackward(true , 1);
break;
case Qt::Key_F5:
if(ui->lineEdit->selectedText()<"0" ||ui->lineEdit->selectedText()>"9" )
{
break;
}
num = ui->lineEdit->selectedText().toInt();
num++ ;
if(num > 9)
{
num = 0;
}
ui->lineEdit->insert(QString::number(num));
ui->lineEdit->cursorBackward(true , 1);
break;
case Qt::Key_F1:
qDebug()<<QString("0").toInt();
num = ui->lineEdit->text().length();
length++ ;
if(length > num -1)
{
length = 0;
}
ui->lineEdit->setSelection(length,1);
break;
}
}