Qt5:QML:LocalStorage

小灰灰 2022-07-14 01:07 141阅读 0赞

## 简介 ##

LocalStorage是本地SQLite的数据库，程序关闭后仍存在，用于持久化数据。比如游戏数据的本地保存等等，在windows 10中位于(储存在哪不重要 搜一下OfflineStorage) 比如

C:\Users\用户\AppData\Local\localstorage\QML\OfflineStorage\Databases

文件夹中

## 示例代码 ##

import QtQuick 2.5
    import QtQuick.Controls 1.4
    import QtQuick.Layouts 1.1
    import QtQuick.LocalStorage 2.0
    
    
    ApplicationWindow {
        visible: true
        width: 800
        height: 600
        title: qsTr("localstorage")
    
        property var localdb
    
        ListModel {
            id:idListMode
            ListElement {
                name: "testname"
                score: "99.5"
            }
        }
    
    
        ColumnLayout {
            id: columnLayout1
            anchors.fill: parent
    
            Rectangle {
                id: rectangle1
                Layout.fillWidth: true
                Layout.fillHeight: true
                height: 200
                color: "#ffffff"
    
                ListView
                {
                    anchors.fill: parent
                    model:idListMode
                    delegate: Text {
                        text: name + " : " + score
                    }
    
                    Component.onCompleted:
                    {
                        openDB();
                        getDBData();
                    }
                }
    
            }
    
            Rectangle {
                id: rectangle2
    
                Layout.fillWidth: true
                height: 100
    
    
                Label {
                    id: label1
                    x: 91
                    y: 35
                    width: 101
                    height: 21
                    text: "姓名"
                    verticalAlignment: Text.AlignVCenter
                    horizontalAlignment: Text.AlignHCenter
                    wrapMode: Text.WordWrap
                }
    
                Label {
                    id: label2
                    x: 91
                    y: 62
                    width: 101
                    height: 21
                    text: "成绩"
                    wrapMode: Text.WordWrap
                    verticalAlignment: Text.AlignVCenter
                    horizontalAlignment: Text.AlignHCenter
                }
    
    
                TextField {
                    id: idName
                    x: 205
                    y: 36
                    placeholderText: qsTr("")
                }
    
                TextField {
                    id: idScore
                    x: 205
                    y: 63
                    inputMask: "00"
    
                }
    
                Button {
                    id: button1
                    x: 416
                    y: 35
                    width: 112
                    height: 48
                    text:"添加"
                    onClicked:
                    {
    
                        if((idName.text.length>0)&&(idScore.text.length))
                        {
                            insertDBData(idName.text,idScore.text);
                            idListMode.append({
       "name":idName.text,"score":idScore.text});
                        }
                        else
                        {
                            console.log("cann't empty");
                        }
                    }
                }
            }
        }
    
        //打开数据库，没有则创建，没有指定表则创建
        function openDB() { 
            localdb = LocalStorage.openDatabaseSync("QQmlValueRecordDB", "1.0", "QML LocalStorage", 1000000);
    
            localdb.transaction(function(tx){ 
    
                tx.executeSql('CREATE TABLE IF NOT EXISTS datasheet(name TEXT, score TEXT)');
            })
        }
    
        //数据库插入数据
        function insertDBData(name,score) { 
            localdb.transaction(function(tx) { 
                tx.executeSql('INSERT INTO datasheet VALUES(?,?)', [name,score]);
            })
    
        }
    
        //从数据库获取数据
        function getDBData() { 
            localdb.transaction(function(tx) { 
                var rs = tx.executeSql('SELECT * FROM datasheet');
    
                for(var i = 0; i < rs.rows.length; i++)
                {
                    idListMode.append({
       "name":rs.rows.item(i).name,"score":rs.rows.item(i).score});
                }
            })
    
        }
    
    }

![这里写图片描述][20161201233449866]

## 源码下载 ##

地址:[github.com/CodeBees/qtExample/tree/master/localstorage][github.com_CodeBees_qtExample_tree_master_localstorage]

[20161201233449866]: /images/20220714/808d519bbcac4404b90aa50b143c5085.png
[github.com_CodeBees_qtExample_tree_master_localstorage]: https://github.com/CodeBees/qtExample/tree/master/localstorage