QListWidget的item检测到被选中行为

• 在维护同事的一个程序时，发现一个小bug。具体情形是这样：有一个对话框，用户可选中QListWidget中的某一项进行打开删除操作；在进行删除操作时，没有去判断item是否被选中进执行删除操作，会引起程序崩溃问题。于是就有了这篇小文。直接上代码:

.h

#ifndef WIDGET_H
#define WIDGET_H

#include 

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();

private slots:

    void on_pushButton_open_clicked();

    void on_pushButton_delete_clicked();
    void setPushButtonEnable();

private:
    Ui::Widget *ui;
    void initFileList();
};

#endif // WIDGET_H

.cpp

#include "widget.h"
#include "ui_widget.h"
#include 
#include 
#include 
#include 
Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    initFileList();
    ui->pushButton_delete->setEnabled(false);//初始化删除按钮不可点击，当有文件选中时才可点击
    connect(ui->listWidget,SIGNAL(itemSelectionChanged()),SLOT(setPushButtonEnable()));//重要的槽连接，检测是否有item改变
}

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

void Widget::on_pushButton_open_clicked()
{
    if(ui->listWidget->count() != 0)
    {
    qDebug() << "open the" << ui->listWidget->currentItem()->text();
    }
}

void Widget::on_pushButton_delete_clicked()
{
    QString runPath = QCoreApplication::applicationDirPath();


    if(QMessageBox::warning(this, "Warning", "Delete this file?", QMessageBox::Yes, QMessageBox::No) == QMessageBox::Yes)
    {
        if(ui->listWidget->count() != 0)
        {
            QFile::remove(runPath + "/File/" + ui->listWidget->currentItem()->text());
            initFileList();
        }
        else
        {
            QMessageBox::warning(this, "Warning", "No file is selected!", QMessageBox::Yes);
        }
    }
    else
    {
        return;
    }
}

void Widget::setPushButtonEnable()
{
    ui->pushButton_delete->setEnabled(true);
}

void Widget::initFileList()
{
    QString runPath = QCoreApplication::applicationDirPath();
    QDir *dir = new QDir(runPath + "/File");
    QStringList filter;
    qDebug() <<"path:" << runPath + "/File";

    filter << "*.txt";
    dir->setNameFilters(filter);
    QList *fileInfo = new QList(dir->entryInfoList(filter));

    ui->listWidget->clear();

    for(int i = 0; i < fileInfo->count();i++)
    {
        ui->listWidget->addItem(fileInfo->at(i).fileName());
    }
}

其中要在程序执行目录下创建File文件夹，才能正常操作。