Qt读写Json格式配置文件

 头文件Config.h

1#pragma once
2
3#include <QVariantMap>
4
5class Config
6{
7public:
8    Config(const QString &fileName);
9    ~Config();
10
11    bool open(const QString &fileName);
12    void sync();
13
14    void write(const QString &key, const QVariant& value);
15
16    QString readString(const QString &key, const QString &default = "");
17    bool readBool(const QString &key, bool default = false);
18    int readInt(const QString &key, int default = 0);
19
20private:
21    QString m_fileName;
22
23    QVariantMap m_cache;
24};

源文件Config.cpp

1#include "Config.h"
2
3#include <QFile>
4#include <QJsonDocument>
5#include <QJsonObject>
6
7
8Config::Config(const QString &fileName)
9    : m_fileName(fileName)
10{
11    open(fileName);
12}
13
14Config::~Config()
15{
16    sync();
17}
18
19bool Config::open(const QString &fileName)
20{
21    QFile file(fileName);
22    if (!file.open(QIODevice::ReadOnly))
23    {
24        return false;
25    }
26    QByteArray allData = file.readAll();
27    file.close();
28
29    QJsonParseError jsonError;
30    QJsonDocument jsonDoc = QJsonDocument::fromJson(allData, &jsonError);
31    if (jsonError.error != QJsonParseError::NoError)
32    {
33        return false;
34    }
35
36    QJsonObject root = jsonDoc.object();
37    m_cache = root.toVariantMap();
38
39    return true;
40}
41
42void Config::sync()
43{
44    QJsonObject root = QJsonObject::fromVariantMap(m_cache);
45    QJsonDocument jsonDoc(root);
46    QByteArray data = jsonDoc.toJson(QJsonDocument::Compact);
47    QFile file(m_fileName);
48    if (file.open(QIODevice::WriteOnly))
49    {
50        file.write(data);
51        file.close();
52    }
53}
54
55void Config::write(const QString &key, const QVariant &value)
56{
57    m_cache.insert(key, value);
58}
59
60QString Config::readString(const QString &key, const QString &default)
61{
62    if (m_cache.contains(key))
63    {
64        return m_cache.value(key).toString();
65    }
66
67    return default;
68}
69
70bool Config::readBool(const QString &key, bool default)
71{
72    if (m_cache.contains(key))
73    {
74        return m_cache.value(key).toBool();
75    }
76
77    return default;
78}
79
80int Config::readInt(const QString &key, int default)
81{
82    if (m_cache.contains(key))
83    {
84        return m_cache.value(key).toInt();
85    }
86
87    return default;
88}