C++ 如何从 QString 初始化 QJsonObject
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How to initialize QJsonObject from QString
提问by Ioan Paul Pirau
I am quite new to Qt and I have a very simple operation that I want to do: I have to obtain the following JSonObject:
我对 Qt 很陌生，我想做一个非常简单的操作：我必须获得以下 JSonObject：
{
"Record1" : "830957 ",
"Properties" :
[{
"Corporate ID" : "3859043 ",
"Name" : "John Doe ",
"Function" : "Power Speaker ",
"Bonus Points" : ["10 ", "45", "56 ", "34", "56", "10 ", "45", "56 ", "34", "56", "10 ", "45", "56 ", "34", "56", "10 ", "45", "56 ", "34", "56", "10 ", "45", "56 ", "34", "56 ", "10", "45 ", "56", "34 ", "56", "45"]
}
]
}
The JSon was checked with this Syntax and Validity checker: http://jsonformatter.curiousconcept.com/and was found valid.
使用此语法和有效性检查器检查 JSon：http://jsonformatter.curiousconcept.com/并发现有效。
I used QJsonValue initialization of String for that and converted it to QJSonObject:
我为此使用了 String 的 QJsonValue 初始化并将其转换为 QJSonObject：
QJsonObject ObjectFromString(const QString& in)
{
QJsonValue val(in);
return val.toObject();
}
I am loading the JSon pasted up from a file:
我正在加载从文件粘贴的 JSon：
QString path = "C:/Temp";
QFile *file = new QFile(path + "/" + "Input.txt");
file->open(QIODevice::ReadOnly | QFile::Text);
QTextStream in(file);
QString text = in.readAll();
file->close();
qDebug() << text;
QJsonObject obj = ObjectFromString(text);
qDebug() <<obj;
There's most certainly a good way to do this because this is not working, and I didn't find any helpful examples
肯定有一个很好的方法来做到这一点，因为这不起作用，而且我没有找到任何有用的例子
回答by TheDarkKnight
QString data; // assume this holds the json string
QJsonDocument doc = QJsonDocument::fromJson(data.toUtf8());
If you want the QJsonObject...
如果你想要QJsonObject...
QJsonObject ObjectFromString(const QString& in)
{
QJsonObject obj;
QJsonDocument doc = QJsonDocument::fromJson(in.toUtf8());
// check validity of the document
if(!doc.isNull())
{
if(doc.isObject())
{
obj = doc.object();
}
else
{
qDebug() << "Document is not an object" << endl;
}
}
else
{
qDebug() << "Invalid JSON...\n" << in << endl;
}
return obj;
}
回答by Joe
You have to follow this step
你必须按照这一步
- convert Qstring to QByteArray first
- convert QByteArray to QJsonDocument
- convert QJsonDocument to QJsonObject
- 首先将 Qstring 转换为 QByteArray
- 将 QByteArray 转换为 QJsonDocument
- 将 QJsonDocument 转换为 QJsonObject
QString str = "{\"name\" : \"John\" }";
QByteArray br = str.toUtf8();
QJsonDocument doc = QJsonDocument::fromJson(br);
QJsonObject obj = doc.object();
QString name = obj["name"].toString();
qDebug() << name;
