Qt中树形控件Tree Widget的使用方法有哪些

本篇内容主要讲解"Qt中树形控件Tree Widget的使用方法有哪些"，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习"Qt中树形控件Tree Widget的使用方法有哪些"吧!

Tree Widget在项目控件组（Item Widgets）里面可以找到。这种控件其实有时还是很有用处的，我主要利用的是带有复选框的树形控件。结果如图所示;

当选中顶层的树形节点时，子节点全部被选中；当取消选择顶层树形节点时，子节点的选中状态将全部被取消，二当选中子节点是，父节点显示部分选中的状态。

几个主要的函数：

setCheckState设置复选框；

ItemIsUserCheckable 项目上是否有复选框

ItemIsEnabled 项目上是否没有被禁用（Enabled可用/Disabled禁用）

ItemIsSelectable 项目是否可以选中

代码：

在mainwindow.h中插入一下代码：

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

在mainwindow构造函数中添加：

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

init函数的实现;

 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函数的实现;

 QString itemText=item->text(0);     //选中     if(Qt::Checked ==item->checkState(0))//全选check打勾     {         QTreeWidgetItem* parent=item->parent();//定义一个节点         int count=item->childCount();//子节点的数目         if(count>0)         {             for(int i=0;ichild(i)->setCheckState(0,Qt::Checked);             }         }         else         {             //是子节点             updateParentItem(item);         }     }     else  if(Qt::Unchecked==item->checkState(0))//存在未选中     {         int count=item->childCount();         if(count>0)         {             for(int i=0;ichild(i)->setCheckState(0,Qt::Unchecked);             }         }         else         {             updateParentItem(item);         }     }

updateParentItem 函数的实现;

  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(selectedCount<=0)      {          parent->setCheckState(0,Qt::Unchecked);      }      else if(selectedCount>0&&selectedCountsetCheckState(0,Qt::PartiallyChecked);      }      else if(selectedCount==childCount)      {          parent->setCheckState(0,Qt::Checked);      }

到此，相信大家对"Qt中树形控件Tree Widget的使用方法有哪些"有了更深的了解，不妨来实际操作一番吧！这里是网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！