# qMRMLNodeComboBox doesn't work

**URL:** <https://discourse.slicer.org/t/qmrmlnodecombobox-doesnt-work/20916>\
**Category:** Development\
**Tags:** extensions-manager, python\
**Created:** [December 5, 2021, 11:53am UTC](https://discourse.slicer.org/t/qmrmlnodecombobox-doesnt-work/20916 "2021-12-05T11:53:43Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![476663616](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/476663616/32/12994_2.png) [@476663616](https://discourse.slicer.org/u/476663616)\
**Post date:** [December 5, 2021, 11:53am UTC](https://discourse.slicer.org/t/qmrmlnodecombobox-doesnt-work/20916/1 "2021-12-05T11:53:43Z")

</div>

Hello everyone, I’m trying to add a new qMRMLNodeComboBox in my extension. However it seems doesn’t work. Like this:  
 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/a/f/aff558183c942954b51850f3197b7efbfb90cebb.png)  
In the .ui file,

```auto
<widget class="qMRMLNodeComboBox" name="SeedsNodeSelector">
        <property name="enabled">
         <bool>false</bool>
        </property>
        <property name="toolTip">
         <string>Select the seed point to refine</string>
        </property>
        <property name="nodeTypes">
         <stringlist>
          <string>vtkMRMLMarkupsFiducialNode</string>
         </stringlist>
        </property>
        <property name="showChildNodeTypes">
         <bool>false</bool>
        </property>
        <property name="noneEnabled">
         <bool>true</bool>
        </property>
       </widget>

```

When I set the property “enabled” as True, it got nothing in list.  
My code about it has been shown below:

```auto
 self.ui.SeedsNodeSelector.connect("currentNodeChanged(vtkMRMLNode*)", self.updateParameterNodeFromGUI)
self._parameterNode.SetNodeReferenceID("SeedPoints", self.ui.SeedsNodeSelector.currentNodeID)
self.ui.SeedsNodeSelector.setCurrentNode(self._parameterNode.GetNodeReference("SeedPoints"))

```

How to deal with it?  
Thanks for any help!

---

<div class="post-metadata">

**Author:** ![RafaelPalomar](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/rafaelpalomar/32/1436_2.png) [@RafaelPalomar](https://discourse.slicer.org/u/RafaelPalomar)\
**Post date:** [December 5, 2021, 12:02pm UTC](https://discourse.slicer.org/t/qmrmlnodecombobox-doesnt-work/20916/2 "2021-12-05T12:02:03Z")

</div>

Hello. Try setting the MRML Scene for your `qMRMLNodeComboBox` and see if it helps. In your code, it would be something like:

```auto
self.ui.SeedsNodeSelector.setMRMLScene(slicer.mrmlScene)

```

---

<div class="post-metadata">

**Author:** ![476663616](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/476663616/32/12994_2.png) [@476663616](https://discourse.slicer.org/u/476663616)\
**Post date:** [December 6, 2021, 7:26am UTC](https://discourse.slicer.org/t/qmrmlnodecombobox-doesnt-work/20916/3 "2021-12-06T07:26:56Z")

</div>

Oh, yes, it works! Thank you very much!  
But I can’t understand it, because I have set them all before:

```auto
uiWidget = slicer.util.loadUI(self.resourcePath('UI/Unet_test.ui'))
self.layout.addWidget(uiWidget)
self.ui = slicer.util.childWidgetVariables(uiWidget)
uiWidget.setMRMLScene(slicer.mrmlScene)

```

Whatever, thanks for your help.

---

<div class="post-metadata">

**Author:** ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)\
**Post date:** [December 7, 2021, 9:47am UTC](https://discourse.slicer.org/t/qmrmlnodecombobox-doesnt-work/20916/4 "2021-12-07T09:47:10Z")

</div>

If you look closely you see that you set it to the wrong object. It is important to be set to the MRML node combobox, instead you set it to the uiWidget object. For automatic propagation of the scene you can add mrmlSceneChanged-\>setMRMLScene signal/slot.

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<div class="post-metadata">

**Author:** ![476663616](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/476663616/32/12994_2.png) [@476663616](https://discourse.slicer.org/u/476663616)\
**Post date:** [December 7, 2021, 11:21am UTC](https://discourse.slicer.org/t/qmrmlnodecombobox-doesnt-work/20916/5 "2021-12-07T11:21:36Z")

</div>

Okay, I get it, thank you. 😀

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<div class="post-metadata">

**Author:** ![zhutouzjq](https://avatars.discourse-cdn.com/v4/letter/z/8797f3/32.png) [@zhutouzjq](https://discourse.slicer.org/u/zhutouzjq)\
**Post date:** [September 16, 2025, 8:47am UTC](https://discourse.slicer.org/t/qmrmlnodecombobox-doesnt-work/20916/6 "2025-09-16T08:47:20Z")

</div>

> [@RafaelPalomar](#):
>
> `self.ui.SeedsNodeSelector.setMRMLScene(slicer.mrmlScene)`

magic, this problem has already troubled me for several days, it has been solved by only one line of code