What are the ways to use the tree control Tree Widget in Qt

This article mainly explains "What are the methods of using Tree Widget in Qt", interested friends may wish to have a look. The method introduced in this paper is simple, fast and practical. Let's let Xiaobian take you to learn "What are the methods of using Tree Widget in Qt"!

Widget Tree can be found in Item Widgets. This kind of control is actually useful sometimes. I mainly use tree controls with checkboxes. The results are shown in the figure;

When the top-level tree node is selected, all child nodes are selected; when the top-level tree node is deselected, all child nodes are deselected, and when the child node is selected, the parent node displays a partially selected state.

Several main functions:

setCheckState setting checkbox;

Is there a checkbox on the ItemIsUserCheckable item

ItemIsEnabled item is not disabled (Enabled/Disabled)

ItemIsSelectable item can be selected

Code:

Insert the following code in mainwindow.h:

void init(); void updateParentItem(QTreeWidgetItem *item); public slots: void treeItemChanged(QTreeWidgetItem* item,int column);

Add to the mainwindow constructor:

init(); connect(ui->treeWidget,SIGNAL(itemChanged(QTreeWidgetItem*,int)),this,SLOT(treeItemChanged(QTreeWidgetItem*,int)));

Implementation of init function;

QTreeWidgetItem* group1=new QTreeWidgetItem(ui->treeWidget); group1->setText(0,"group1"); group1->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable); group1->setCheckState(0,Qt::Unchecked); QTreeWidgetItem* subItem11=new QTreeWidgetItem(group1); subItem11->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable); subItem11->setText(0,"subItem11"); subItem11->setCheckState(0,Qt::Unchecked); QTreeWidgetItem* subItem12=new QTreeWidgetItem(group1); subItem12->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable); subItem12->setText(0,"subItem12"); subItem12->setCheckState(0,Qt::Unchecked); QTreeWidgetItem* subItem13=new QTreeWidgetItem(group1); subItem13->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable); subItem13->setText(0,"subItem11"); subItem13->setCheckState(0,Qt::Unchecked); QTreeWidgetItem* subItem14=new QTreeWidgetItem(group1); subItem14->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable); subItem14->setText(0,"subItem12"); subItem14->setCheckState(0,Qt::Unchecked); QTreeWidgetItem* group2=new QTreeWidgetItem(ui->treeWidget); group2->setText(0,"group2"); group2->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable); group2->setCheckState(0,Qt::Unchecked); QTreeWidgetItem* subItem1=new QTreeWidgetItem(group2); subItem1->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable); subItem1->setText(0,"subItem11"); subItem1->setCheckState(0,Qt::Unchecked); QTreeWidgetItem* subItem2=new QTreeWidgetItem(group2); subItem2->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable); subItem2->setText(0,"subItem12"); subItem2->setCheckState(0,Qt::Unchecked); QTreeWidgetItem* subItem3=new QTreeWidgetItem(group2); subItem3->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable); subItem3->setText(0,"subItem11"); subItem3->setCheckState(0,Qt::Unchecked); QTreeWidgetItem* subItem4=new QTreeWidgetItem(group2); subItem4->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable); subItem4->setText(0,"subItem12"); subItem4->setCheckState(0,Qt::Unchecked); QTreeWidgetItem* group3=new QTreeWidgetItem(ui->treeWidget); group3->setText(0,"group3"); group3->setFlags(Qt::ItemIsAutoTristate|Qt::ItemIsEnabled|Qt::ItemIsSelectable); group3->setCheckState(0,Qt::Unchecked); QTreeWidgetItem* subItem111=new QTreeWidgetItem(group3); subItem111->setFlags(Qt::ItemIsAutoTristate|Qt::ItemIsEnabled|Qt::ItemIsSelectable); subItem111->setText(0,"subItem111"); subItem111->setCheckState(0,Qt::Unchecked); QTreeWidgetItem* subItem112=new QTreeWidgetItem(group3); subItem112->setFlags(Qt::ItemIsAutoTristate|Qt::ItemIsEnabled|Qt::ItemIsSelectable); subItem112->setText(0,"subItem112"); subItem112->setCheckState(0,Qt::Unchecked);

treeItemChanged function implementation;

QString itemText=item->text(0); //Select if(Qt::Checked ==item->checkState(0))//check All Check { QTreeWidgetItem* parent=item->parent();//Define a node int count=item->childCount();//Number of children if(count>0) { for(int i=0;ichild(i)->setCheckState(0,Qt::Checked); } } else { //is a child node updateParentItem(item); } } else if(Qt::Unchecked==item->checkState(0))//Unchecked exists { int count=item->childCount(); if(count>0) { for(int i=0;ichild(i)->setCheckState(0,Qt::Unchecked); } } else { updateParentItem(item); } }

Implementation of updateParentItem function;

QTreeWidgetItem* parent=item->parent(); if(parent==NULL) { return; } int selectedCount =0; int childCount =parent->childCount(); for(int i=0;ichild(i); if(childItem->checkState(0)==Qt::Checked) { selectedCount++; } } if(selectedCountsetCheckState(0,Qt::Unchecked); } else if(selectedCount>0&&selectedCountsetCheckState(0,Qt::PartiallyChecked); } else if(selectedCount==childCount) { parent->setCheckState(0,Qt::Checked); } At this point, I believe that everyone has a deeper understanding of "what are the methods of using the Tree Widget in Qt", so let's actually operate it! Here is the website, more related content can enter the relevant channels for inquiry, pay attention to us, continue to learn!