Qt linedeit中数据的读取和计算

leble和linedeit的数据显示是相同的

【数据显示】

connect(btn,&QPushButton::clicked,this,[=](){
        QString meijie;
        jieguo->setText(meijie.setNum(jisuan(line)));
        l2->setText(meijie.setNum(jisuanint(line)));});

【数据计算】

//获取lineedit或label中的数据并在linedeit中显示【一般在label中显示】doubleMainWindow::jisuan(QLineEdit *l){bool ok;
    QString lsnum;
    lsnum=l->text();int num = lsnum.toInt(&ok);double zuizhongjieguo = num*num*3.14;return zuizhongjieguo;}intMainWindow::jisuanint(QLineEdit *l){bool ok;
    QString lsnum;
    lsnum=l->text();int num = lsnum.toInt(&ok);double zuizhongjieguo = num*num*3.14;return zuizhongjieguo;}

【本节代码】

#include"mainwindow.h"#include"ui_mainwindow.h"#include<QGridLayout>//布局管理器MainWindow::MainWindow(QWidget *parent):QMainWindow(parent),ui(new Ui::MainWindow){setFixedSize(400,200);
    ui->setupUi(this);
    l1 =newQLabel(this);
    l1->setText("输入圆的面积:");//label类
    line =newQLineEdit(this);//这是一个编辑框//label可以用来显示数字此处决定用linedit显示结果
    l2 =newQLabel(this);
    jieguo =newQLineEdit(this);
    l2->setText("int类型结果");
    btn =newQPushButton(this);
    btn->setText("计算结果是");
    l1->move(0,0);
    line->move(100,0);
    btn->move(0,100);
    jieguo->move(100,100);
    l2->move(200,100);connect(btn,&QPushButton::clicked,this,[=](){
        QString meijie;
        jieguo->setText(meijie.setNum(jisuan(line)));
        l2->setText(meijie.setNum(jisuanint(line)));});}//获取lineedit或label中的数据并在linedeit中显示【一般在label中显示】doubleMainWindow::jisuan(QLineEdit *l){bool ok;
    QString lsnum;
    lsnum=l->text();int num = lsnum.toInt(&ok);double zuizhongjieguo = num*num*3.14;return zuizhongjieguo;}intMainWindow::jisuanint(QLineEdit *l){bool ok;
    QString lsnum;
    lsnum=l->text();int num = lsnum.toInt(&ok);double zuizhongjieguo = num*num*3.14;return zuizhongjieguo;}MainWindow::~MainWindow(){delete ui;}