How to Connect C Signals to QML Slots with QString Parameters?

Connecting C Signals to QML Slots

Issue:

When attempting to send a QString parameter from a C signal to a QML slot, an error occurs stating, "No such slot QDeclarativeRectangle_QML_2::updateViewWithItem(QString)."

Solution:

Using Connections

To resolve this issue, connections should be employed instead of direct slot connections.

1. Expose C Object to QML:
   Add the C object (myObj) to the QML context property using setContextProperty() in the main C code.

   <code class="cpp">qmlVectorForm->rootContext()->setContextProperty("YourObject", myOb);</code>

2. Define Signal:
   In C , define the signal as:

   <code class="cpp">finishedGatheringDataForItem(QString signalString);</code>

3. Add Connections in QML:

   In the QML file, add connections to the exposed object:

   <code class="qml">Connections {
       target: YourObject
       onFinishedGatheringDataForItem: {
           qmlString = signalString
       }
   }</code>

By using connections, the QML slot can receive the QString parameter correctly without the previous error.

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