Conversion methods for QJsonValue always return their default value

Question

I am trying to convert QJsonValues into their correct data types, but the conversion always ends up returning their default value.

For example, I have the following JSON object:

{
    "val1": 99,
    "val2": true,
    "val3": "test"
}

I'm getting these values with:

QJsonValue val1 = jsonObj.value("val1");
QJsonValue val2 = jsonObj.value("val2");
QJsonValue val3 = jsonObj.value("val3");

Now, if I check these QJsonValues in the Debug view, they all have their correct value and data types.

I'm seeing...

val1 as 99 - QJsonValue(Number)
val2 as true - QJsonValue(Bool)
val3 as "test" - QJsonValue(String)

I now do the following:

int valInt1 = val1.toInt();
bool valBool2 = val2.toBool();
QString valString3 = val3.toString();

This will give me 0 for valInt1, false for valBool2 and "test" for valString3. For some reason, toString() seems to be working correctly, but the other conversion methods all result in their default value.

With val1 I can do the following to make it work:

int valInt1 = val1.toString().toInt();

But that is not an option for bool values.

Does anyone know how I could solve this problem? I believe I'm doing everything right here. Not sure what the issue might be and the documentation does things exactly how I would do them, but the conversions always return default values.

score 1 · Accepted Answer · answered Oct 04 '19 at 10:13

I have solved this problem for now by converting the JsonObject to a QVariantMap and ignoring the QJsonValues. They are either bugged or I do not understand how they work.

QVariantMap map = jsonObj.toVariantMap();

int valInt1 = map.value("val1").toInt();
bool valBool2 = map.value("val2").toBool();
QString valString3 = map.value("val3").toString();

Conversion methods for QJsonValue always return their default value

1 Answers1