QTreeWidget——信号处理
文章目录
- 基本属性
- 信号
-
- 一、信号种类
- 二、信号测试
-
- 1、currentItemChanged、itemCollapsed、itemExpanded三个信号的测试
- 2、itemActivated信号
- 3、 itemChanged信号
- 4、其余信号的测试代码（包含以上代码）
基本属性
信号
一、信号种类
//当前项发生变化时触发，使用后不会触发itemClicked、itemDoubleClicked这两个信号，支持鼠标和键盘触发
void currentItemChanged(QTreeWidgetItem *current, QTreeWidgetItem *previous)
//伸展子项和收缩子项
void itemCollapsed(QTreeWidgetItem *item)
void itemExpanded(QTreeWidgetItem *item)
//激活项时触发
void itemActivated(QTreeWidgetItem *item, int column)
//测试发现只对一级节点的触发有响应
void itemChanged(QTreeWidgetItem *item, int column)
//鼠标单击触发
void itemClicked(QTreeWidgetItem *item, int column)
//鼠标双击触发
void itemDoubleClicked(QTreeWidgetItem *item, int column)
//鼠标光标的移动到项上时触发，前提打开鼠标跟踪
void itemEntered(QTreeWidgetItem *item, int column)
//鼠标按下时触发
void itemPressed(QTreeWidgetItem *item, int column)
//当项发生变化时，可以通过键盘上下键触发
void itemSelectionChanged()
二、信号测试
1、currentItemChanged、itemCollapsed、itemExpanded三个信号的测试
测试效果：
部分测试代码
int MainWindow::setTreeItem()
{
//关掉默认的展开图标
ui->m_treeWidget->setRootIsDecorated(false);
QFont font("黑体",16);
//创建一级父类项
QTreeWidgetItem *item_parent = new QTreeWidgetItem(ui->m_treeWidget);
item_parent->setIcon(0,QIcon(":/new/prefix1/picture/Down.png"));
//设置一列数据
ui->m_treeWidget->setColumnCount(1);
item_parent->setFont(0,font);
//item_parent->setTextColor(0,Qt::white);
item_parent->setText(0,QString::fromLocal8Bit("设备信息"));
//添加二级项
QTreeWidgetItem *item_child = new QTreeWidgetItem(item_parent);
item_child->setIcon(0,QIcon(":/new/prefix1/picture/AP.png"));
item_child->setTextAlignment(0,Qt::AlignLeft | Qt::AlignVCenter);
item_child->setText(0,QString::fromLocal8Bit("设备一"));
item_child->setSelected(false);
//所选项的展开与收缩信号
connect(ui->m_treeWidget,SIGNAL(itemExpanded(QTreeWidgetItem *)),this,
SLOT(On_DouClickedTreeOpen_Slots(QTreeWidgetItem *)));
connect(ui->m_treeWidget,SIGNAL(itemCollapsed(QTreeWidgetItem *)),this,
SLOT(On_DouClickedTreeClose_Slots(QTreeWidgetItem *)));
connect(ui->m_treeWidget,SIGNAL(currentItemChanged(QTreeWidgetItem *, QTreeWidgetItem *)),this,
SLOT(On_CurrentItemChanged_Slots(QTreeWidgetItem *,QTreeWidgetItem *)));
return 0;
}
void MainWindow::On_DouClickedTreeClose_Slots(QTreeWidgetItem *item)
{
item->setIcon(0,QIcon(":/new/prefix1/picture/Down.png"));
}
void MainWindow::On_CurrentItemChanged_Slots(QTreeWidgetItem *curren, QTreeWidgetItem *previous)
{
if(previous != NULL)
qDebug()<<curren->text(0)<<previous->text(0);
}
void MainWindow::On_DouClickedTreeOpen_Slots(QTreeWidgetItem *item)
{
item->setIcon(0,QIcon(":/new/prefix1/picture/Up.png"));
}
子项伸展和收缩的应用测试
void MainWindow::init()
{
//关闭头部信息
ui->m_treeWidget->header()->setVisible(false);
//关掉默认的展开图标
ui->m_treeWidget->setRootIsDecorated(false);
//初始qtree的宽高
ui->m_treeWidget->setFixedSize(T_WIDTH,T_HEIGHT);
//禁用滑动块
ui->m_treeWidget->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
ui->m_treeWidget->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
setTreeItem();
}
int MainWindow::setTreeItem()
{
QFont font("黑体",16);
//创建一级父类项
QTreeWidgetItem *item_parent = new QTreeWidgetItem(ui->m_treeWidget);
item_parent->setSizeHint(0,QSize(C_WIDTH,C_HEIGHT));
item_parent->setIcon(0,QIcon(":/new/prefix1/picture/Down.png"));
//设置一列数据
ui->m_treeWidget->setColumnCount(1);
item_parent->setFont(0,font);
item_parent->setText(0,QString::fromLocal8Bit("设备信息"));
//设置对齐方式
item_parent->setTextAlignment(0,Qt::AlignVCenter);
addChildItem(item_parent);
//所选项的展开与收缩信号
connect(ui->m_treeWidget,SIGNAL(itemExpanded(QTreeWidgetItem *)),this,
SLOT(On_DouClickedTreeOpen_Slots(QTreeWidgetItem *)));
connect(ui->m_treeWidget,SIGNAL(itemCollapsed(QTreeWidgetItem *)),this,
SLOT(On_DouClickedTreeClose_Slots(QTreeWidgetItem *)));
connect(ui->m_treeWidget,SIGNAL(currentItemChanged(QTreeWidgetItem *, QTreeWidgetItem *)),this,
SLOT(On_CurrentItemChanged_Slots(QTreeWidgetItem *,QTreeWidgetItem *)));
return 0;
}
void MainWindow::On_DouClickedTreeOpen_Slots(QTreeWidgetItem *item)
{
if(item->text(0) == QString::fromLocal8Bit("设备信息"))
{
item->setIcon(0,QIcon(":/new/prefix1/picture/Up.png"));
//根据子节点数目更新宽度
int num = item->childCount();
if(num > 0)
{
int h = num * C_HEIGHT + T_HEIGHT;
ui->m_treeWidget->setFixedSize(T_WIDTH,h);
}
}
}
void MainWindow::On_DouClickedTreeClose_Slots(QTreeWidgetItem *item)
{
if(item->text(0) == QString::fromLocal8Bit("设备信息"))
{
item->setIcon(0,QIcon(":/new/prefix1/picture/Down.png"));
//回复默认宽高
ui->m_treeWidget->setFixedSize(T_WIDTH,T_HEIGHT);
}
}
2、itemActivated信号
效果图：
测试鼠标双击控制和使用键盘的Enter触发
3、 itemChanged信号
测试发现只对一级节点的触发有响应，这里关闭了所有项的默认图标
//QSS:关闭子项的默认图标
QTreeView::branch:has-children:!has-siblings:closed,
QTreeView::branch:closed:has-children:has-siblings {
border-image: none;
image: none;
}
QTreeView::branch:open:has-children:!has-siblings,
QTreeView::branch:open:has-children:has-siblings {
border-image: none;
image: none;
}
效果图：
4、其余信号的测试代码（包含以上代码）
void MainWindow::init()
{
//关闭头部信息
ui->m_treeWidget->header()->setVisible(false);
//关掉默认的展开图标
ui->m_treeWidget->setRootIsDecorated(false);
//初始qtree的宽高
ui->m_treeWidget->setFixedSize(T_WIDTH,T_HEIGHT);
//禁用滑动块
ui->m_treeWidget->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
ui->m_treeWidget->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
setTreeItem();
}
int MainWindow::setTreeItem()
{
QFont font("黑体",16);
//创建一级父类项
QTreeWidgetItem *item_parent = new QTreeWidgetItem(ui->m_treeWidget);
item_parent->setSizeHint(0,QSize(C_WIDTH,C_HEIGHT));
item_parent->setIcon(0,QIcon(":/new/prefix1/picture/Down.png"));
//设置一列数据
ui->m_treeWidget->setColumnCount(1);
item_parent->setFont(0,font);
item_parent->setText(0,QString::fromLocal8Bit("设备信息"));
//设置对齐方式
item_parent->setTextAlignment(0,Qt::AlignVCenter);
addChildItem(item_parent);
//所选项的展开与收缩信号
connect(ui->m_treeWidget,SIGNAL(itemExpanded(QTreeWidgetItem *)),this,
SLOT(On_DouClickedTreeOpen_Slots(QTreeWidgetItem *)));
connect(ui->m_treeWidget,SIGNAL(itemCollapsed(QTreeWidgetItem *)),this,
SLOT(On_DouClickedTreeClose_Slots(QTreeWidgetItem *)));
connect(ui->m_treeWidget,SIGNAL(currentItemChanged(QTreeWidgetItem *, QTreeWidgetItem *)),this,
SLOT(On_CurrentItemChanged_Slots(QTreeWidgetItem *,QTreeWidgetItem *)));
connect(ui->m_treeWidget,SIGNAL(itemActivated(QTreeWidgetItem *, int)),this,
SLOT(On_ItemActivated_Slots(QTreeWidgetItem *,int)));
connect(ui->m_treeWidget,SIGNAL(itemChanged(QTreeWidgetItem *, int)),this,
SLOT(On_ItemChanged_Slot(QTreeWidgetItem *,int)));
//itemClicked
connect(ui->m_treeWidget,SIGNAL(itemClicked(QTreeWidgetItem *, int)),this,
SLOT(On_ItemClicked_Slots(QTreeWidgetItem *,int)));
connect(ui->m_treeWidget,SIGNAL(itemDoubleClicked(QTreeWidgetItem *, int)),this,
SLOT(On_ItemDoubleClicked_Slots(QTreeWidgetItem *,int)));
connect(ui->m_treeWidget,SIGNAL(itemPressed(QTreeWidgetItem *, int)),this,
SLOT(On_ItemPressed_Slots(QTreeWidgetItem *,int)));
connect(ui->m_treeWidget,SIGNAL(itemSelectionChanged()),this,
SLOT(On_ItemSelectionChanged_Slots()));
return 0;
}
/**
* @brief MainWindow::addChildItem 添加二级子项
* @param parentItem
*/
void MainWindow::addChildItem(QTreeWidgetItem *parentItem)
{
//添加二级项，为了是效果更加明显多添加几个子节点
for(int i = 0;i < 6;i++)
{
QTreeWidgetItem *item_child = new QTreeWidgetItem(parentItem);
//itemActivated
item_child->setSizeHint(0,QSize(C_WIDTH,C_HEIGHT));
item_child->setIcon(0,QIcon(":/new/prefix1/picture/AP.png"));
item_child->setTextAlignment(0,Qt::AlignLeft | Qt::AlignVCenter);
QString test_str = QString::fromLocal8Bit("设备_");
test_str.append(QString::number(i));
item_child->setText(0,test_str);
QTreeWidgetItem *item_child_child = new QTreeWidgetItem(item_child);
item_child_child->setSizeHint(0,QSize(C_WIDTH,C_HEIGHT));
item_child_child->setTextAlignment(0,Qt::AlignLeft | Qt::AlignVCenter);
//item_child->setIcon(0,QIcon(":/new/prefix1/picture/AP.png"));
item_child_child->setText(0,QString::fromLocal8Bit("信息"));
}
}
void MainWindow::On_ItemSelectionChanged_Slots()
{
qDebug()<<QString::fromLocal8Bit("当前项发生改变");
}
void MainWindow::On_DouClickedTreeClose_Slots(QTreeWidgetItem *item)
{
if(item->text(0) == QString::fromLocal8Bit("设备信息"))
{
item->setIcon(0,QIcon(":/new/prefix1/picture/Down.png"));
//回复默认宽高
ui->m_treeWidget->setFixedSize(T_WIDTH,T_HEIGHT);
}
}
void MainWindow::On_ItemActivated_Slots(QTreeWidgetItem *item, int n)
{
//qDebug()<text(0)<
}
void MainWindow::On_ItemChanged_Slot(QTreeWidgetItem *item, int n)
{
qDebug()<<item->text(0)<<n;
}
void MainWindow::On_ItemClicked_Slots(QTreeWidgetItem *item, int n)
{
qDebug()<<QString::fromLocal8Bit("单击")<<item->text(0)<<n;
}
void MainWindow::On_ItemDoubleClicked_Slots(QTreeWidgetItem *item, int n)
{
qDebug()<<QString::fromLocal8Bit("双击")<<item->text(0)<<n;
}
void MainWindow::On_ItemPressed_Slots(QTreeWidgetItem *item, int n)
{
qDebug()<<QString::fromLocal8Bit("按下")<<item->text(0)<<n;
}
void MainWindow::On_CurrentItemChanged_Slots(QTreeWidgetItem *curren, QTreeWidgetItem *previous)
{
//这里做判断是防止代码初始化时出错，因为初始化时previous == NULL
// if(previous != NULL)
// qDebug()<text(0)<text(0);
}
void MainWindow::On_DouClickedTreeOpen_Slots(QTreeWidgetItem *item)
{
if(item->text(0) == QString::fromLocal8Bit("设备信息"))
{
item->setIcon(0,QIcon(":/new/prefix1/picture/Up.png"));
//根据子节点数目更新宽度
int num = item->childCount();
if(num > 0)
{
int h = num * C_HEIGHT + T_HEIGHT;
ui->m_treeWidget->setFixedSize(T_WIDTH,h);
}
}
}```