Qt QML dropdown list like in HTML

问题:

Simple thing, but can't get find it. I want a simple dropdown selection box with a couple of selections. Like in HTML

<select>
<option>1</option>
<option>2</option>
</select>

what is the code for QML for that ?

回答1:

Here's a simple example that could maybe be used as a starting point:

import QtQuick 1.0

Rectangle {
    width:400;
    height: 400;

    Rectangle {
            id:comboBox
            property variant items: ["Item 1", "Item 2", "Item 3"]
            property alias selectedItem: chosenItemText.text;
            property alias selectedIndex: listView.currentIndex;
            signal comboClicked;
            width: 100;
            height: 30;
            z: 100;
            smooth:true;

            Rectangle {
                id:chosenItem
                radius:4;
                width:parent.width;
                height:comboBox.height;
                color: "lightsteelblue"
                smooth:true;
                Text {
                    anchors.top: parent.top;
                    anchors.left: parent.left;
                    anchors.margins: 8;
                    id:chosenItemText
                    text:comboBox.items[0];
                    font.family: "Arial"
                    font.pointSize: 14;
                    smooth:true
                }

                MouseArea {
                    anchors.fill: parent;
                    onClicked: {
                        comboBox.state = comboBox.state==="dropDown"?"":"dropDown"
                    }
                }
            }

            Rectangle {
                id:dropDown
                width:comboBox.width;
                height:0;
                clip:true;
                radius:4;
                anchors.top: chosenItem.bottom;
                anchors.margins: 2;
                color: "lightgray"

                ListView {
                    id:listView
                    height:500;
                    model: comboBox.items
                    currentIndex: 0
                    delegate: Item{
                        width:comboBox.width;
                        height: comboBox.height;

                        Text {
                            text: modelData
                            anchors.top: parent.top;
                            anchors.left: parent.left;
                            anchors.margins: 5;

                        }
                        MouseArea {
                            anchors.fill: parent;
                            onClicked: {
                                comboBox.state = ""
                                var prevSelection = chosenItemText.text
                                chosenItemText.text = modelData
                                if(chosenItemText.text != prevSelection){
                                    comboBox.comboClicked();
                                }
                                listView.currentIndex = index;
                            }
                        }
                    }
                }
            }

            Component {
                id: highlight
                Rectangle {
                    width:comboBox.width;
                    height:comboBox.height;
                    color: "red";
                    radius: 4
                }
            }

            states: State {
                name: "dropDown";
                PropertyChanges { target: dropDown; height:40*comboBox.items.length }
            }

            transitions: Transition {
                NumberAnimation { target: dropDown; properties: "height"; easing.type: Easing.OutExpo; duration: 1000 }
            }
        }
    }

回答2:

For new users, there is a built in ComboBox in Qt5.3 QtQuick.Controls ComboBox - Reference.

Example from Documentation:

import QtQuick 2.2
import QtQuick.Controls 1.2

ComboBox {
  id: combo
  editable: true
  model: ListModel {
   id: model
   ListElement { text: "Banana"; color: "Yellow" }
   ListElement { text: "Apple"; color: "Green" }
   ListElement { text: "Coconut"; color: "Brown" }
 }
 onAccepted: {
  if (combo.find(currentText) === -1) {
     model.append({text: editText})
     currentIndex = combo.find(editText)
   }
 }
}

Note: I had to post it as an answer, since the text is too long for a comment.

回答3:

I've been using approaches with ComboBoxStyle (customization capabilities limited) and completely custom implementations, but they have a lot of limitations with focus management and z-index management.

I've end up with the implementation of ComboBox which consists of 2 parts: a header which you actually put somewhere and a dropdown component which you create dynamically. The latter consists of an Item covering everything (and intercepting mouse activity) and a dropdown which is carefully positioned below the header.

Code is pretty massive to included here so you can see details in my blogpost with all the code

回答4:

If you targeting Nokia devices (Symbian or Meego), you could use high-level Qt Quick components. I believe Menu is something similar to html's select.

See http://doc.qt.nokia.com/qt-components-symbian/qml-menu.html or http://harmattan-dev.nokia.com/docs/library/html/qt-components/qt-components-meego-menu.html

回答5:

If you are targeting Symbian, there is SelectionListItem and SelectionDialog: http://doc.qt.nokia.com/qt-components-symbian/qml-selectionlistitem.html