Qlistview双击打不开slot [复制链接]

QDirModel * model = new QDirModel(this);
....
QListview * lv = new QListview；
....
connect(lv,SIGNAL(doubleClicked(const QModelIndex &)),this,SLOT(on_doubleClicked(const QModelIndex &)));

void on_doubleClicked(const QModelIndex & index)
{
QModelIndex index = lv->currentIndex();
    
    if(index.isValid())
    return;    

    lv->edit(index);
    lv->update(index);    

    if(model->isDir(index))
    {
        lv->setRootIndex(index);
    }
    else
    {
        QString str = model->filePath(index);
        QFile f("./qt.txt");
        f.open( QIODevice::WriteOnly);
        QTextStream s( &f );
        s << str << endl;
                f.close();
}
    目的是实现双击 将index文件路径输出到当前目录下的qt.txt文件中，可是我双击却不起作用阿？ 貌似好像是index的问题吧

貌似槽函数写的不对吧，参数index已经是通过信号传值过来了，应该是那么写吧：
QString filePath = modelList->filePath(index);
QFileInfo fileInfo = modelList->fileInfo(index);
    if(fileInfo.isDir())
    {

    }

引用第1楼pear_2268于2010-05-19 10:31发表的  :
貌似槽函数写的不对吧，参数index已经是通过信号传值过来了，应该是那么写吧：
QString filePath = modelList->filePath(index);
QFileInfo fileInfo = modelList->fileInfo(index);
    if(fileInfo.isDir())
    {
.......

我用gdb调试了一下有问题：
[Thread debugging using libthread_db enabled]

Program received signal SIGSEGV, Segmentation fault.
0x00826bb6 in QAbstractItemModelPrivate::indexValid (this=0x670066, index=...)
    at ../../include/QtCore/private/../../../src/corelib/kernel/qabstractitemmodel_p.h:102
102    ../../include/QtCore/private/../../../src/corelib/kernel/qabstractitemmodel_p.h: 没有该文件或目录.
    in ../../include/QtCore/private/../../../src/corelib/kernel/qabstractitemmodel_p.h
Current language:  auto
The current source language is "auto; currently c++".
(gdb)

我将void file:: on_doubleClicked(const QModelIndex & index) 的index去掉（即变为void file:: on_doubleClicked(const QModelIndex & ））试了一下，gdb调试信息变了：

Program received signal SIGSEGV, Segmentation fault.
0x007c0920 in QPointer<QItemSelectionModel>::operator QItemSelectionModel* (
    this=0x63006d)
    at ../../include/QtCore/../../src/corelib/kernel/qpointer.h:78
78    ../../include/QtCore/../../src/corelib/kernel/qpointer.h: 没有该文件或目录.
    in ../../include/QtCore/../../src/corelib/kernel/qpointer.h
Current language:  auto
The current source language is "auto; currently c++".

QDirModel * model = new QDirModel(this);
....
QListview * lv = new QListview；

lv->setModel(model); //这个得加上吧?
....
connect(lv,SIGNAL(doubleClicked(const QModelIndex &)),this,SLOT(on_doubleClicked(const QModelIndex &)));

void on_doubleClicked(const QModelIndex & index)
{
//QModelIndex index = lv->currentIndex();   这里是多此一举, 函数的参数已经传进来了,更何况你真要自己去取，名字也不能跟传入参数一样阿，重名了。

    
    if(index.isValid())  //这个逻辑有问题，为什么有效地Index还要返回呢？ 改成if(!index.isValid())
        return;    

    //下边两句也是莫名其妙
    //lv->edit(index);
    //lv->update(index);    

    if(model->isDir(index))
    {
        lv->setRootIndex(index);
    }
    else
    {
        QString str = model->filePath(index);
        QFile f("./qt.txt");
        f.open( QIODevice::WriteOnly);
        QTextStream s( &f );
        s << str << endl;
                f.close();
}
    目的是实现双击 将index文件路径输出到当前目录下的qt.txt文件中，可是我双击却不起作用阿？ 貌似好像是index的问题吧

引用第4楼foxyz于2010-05-19 13:35发表的  :
QDirModel * model = new QDirModel(this);
....
QListview * lv = new QListview；
lv->setModel(model); //这个得加上吧?
.......

参照仁兄的意见，我已经改过了但是调试的时候仍然出现：
Program received signal SIGSEGV, Segmentation fault.
0x00826bb6 in QAbstractItemModelPrivate::indexValid (this=0x670066, index=...)
    at ../../include/QtCore/private/../../../src/corelib/kernel/qabstractitemmodel_p.h:102
102    ../../include/QtCore/private/../../../src/corelib/kernel/qabstractitemmodel_p.h: 没有该文件或目录.
    in ../../include/QtCore/private/../../../src/corelib/kernel/qabstractitemmodel_p.h
Current language:  auto
The current source language is "auto; currently c++".
(gdb)

Segmentation fault 一般出现在访问一个非法地址. 你最好把头文件和cpp文件都贴出来。才好看出是啥原因。不清楚你的平台是什么。如果是unix可以用dbx来调试

还有，每次编译前最好clean一下！ 否则moc*.cpp和ui_*.h等文件也会引来错误

我又试了一下，将代码改为：
if(model->isDir(index))
    {
        lv->setRootIndex(index);
    }
    else
    {
       QMessageBox::information(this,tr("Mplayer"),tr("Failed to open %1").arg(model->filePath(index)));
   }
问题依旧阿
Program received signal SIGSEGV, Segmentation fault.
0x00826bb6 in QAbstractItemModelPrivate::indexValid (this=0x670066, index=...)
    at ../../include/QtCore/private/../../../src/corelib/kernel/qabstractitemmodel_p.h:102
102    ../../include/QtCore/private/../../../src/corelib/kernel/qabstractitemmodel_p.h: 没有该文件或目录.
    in ../../include/QtCore/private/../../../src/corelib/kernel/qabstractitemmodel_p.h
Current language:  auto
The current source language is "auto; currently c++".
(gdb)

由此大概可以说明 index参数没有传进来

引用第6楼foxyz于2010-05-19 13:56发表的  :
Segmentation fault 一般出现在访问一个非法地址. 你最好把头文件和cpp文件都贴出来。才好看出是啥原因。不清楚你的平台是什么。如果是unix可以用dbx来调试

我用的是linux ubuntu 9.10
我之前用的model是QFileSystemModel，在主机上运行良好，但是一移植到mini2440开发板上就提示出错了，所以只能用QDirModel  了

qmake -project
qmake
make
编译可以通过，就是出现段错误
make clean

我没有弄UI界面，纯指令搭建
现在的问题是不清楚 QModelIndex index 如何传递参数呢？

问题已解决