QT day3作业

有点不对，不能运行了，怪事 

#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
}

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

//字体
void Widget::on_fountBtn_clicked()
{
    bool ok;
    QFont  f = QFontDialog::getFont(
                &ok,
                QFont("宋体",10,2),
                this,
                "选择字体");
    if(ok)
    {
        ui->textEdit->setCurrentFont(f);

    }
    else {
        QMessageBox::information(this,"错误","用户没有选择字体");
    }
}

void Widget::on_colorBtn_clicked()
{
    QColor c = QColorDialog::getColor(
             QColor(100,230,320),
             this,
             "选中颜色");
    if(c.isValid())
    {
        ui->textEdit->setTextColor(c);
    }
    else {
        QMessageBox::information(this,"错误","未选择");
    }
}


void Widget::on_openBtn_clicked()
{
    QString fileName = QFileDialog::getOpenFileName(
                this,
                "选择文件",
                "./",
                "所有文件(*.*) ;; 头文件(*.h) ;; 图片(*.png *.xpm *.jpg) ;; 文本(*.txt)");
    //输出
    qDebug()<textEdit->setText(QString::fromLocal8Bit(msg));

}

void Widget::on_saveBtn_clicked()
{

    QString text = ui->textEdit->toPlainText();
    QString fileName = "test.txt";
    QFile file(fileName);
    if(!file.exists())
    {
      if(file.open(QIODevice::WriteOnly|QIODevice::Text))
        {
            QTextStream out(&file);
            out << text;
            file.close();
        }
    }
    else {
        QMessageBox::information(this,"错误","文件已存在");
        return;
    }

//    QString fileName = QFileDialog::getOpenFileName(
//                this,
//                "选择文件",
//                "./",
//                "所有文件(*.*) ;; 头文件(*.h) ;; 图片(*.png *.xpm *.jpg) ;; 文本(*.txt)");
//    //输出
//    qDebug()<