getResourceId finds no ID in custom control

Question

I'm trying to create a control (a panel that expands and contracts when a header is clicked), and I found some code online. In the constructor, I have

TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.MyControl);
...
int headerId = array.getResourceId(R.styleable.MyControl_header, -1);

The control is being created in a layout file with the following XML:

<MyControl
        android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/drawer"
        header="@+id/header" content="@+id/drawerContent"
        android:layout_below="@id/contentContainer" android:background="#00FF00">
    <TextView android:layout_height="wrap_content" android:layout_width="match_parent" android:id="@id/header"
            android:text="This is a header"/>

    <TextView android:layout_height="wrap_content" android:layout_width="match_parent" android:id="@id/drawerContent"
            android:text="@string/sample_text" />
</MyControl>

The problem is, getResourceId() comes back with -1 (i.e., it can't seem to find the resource set to the attribute).

Any idea why?

EDIT: Forgot to include my attrs.xml file:

<resources>
<declare-styleable name="MyControl">
    <attr name="collapsedHeight" format="dimension" />
    <attr name="header" format="reference" />
    <attr name="content" format="reference" />
    <attr name="animationDuration" format="integer" />
</declare-styleable>

EDIT 2: Somehow, I didn't think to check the other attributes--there were a couple of other attributes I had added. I checked their values in the debugger, too, and it looks like they're defaulting, as well. So it's not an issue with getResourceId, it's something to do with how I'm getting the attributes in general. I'm new to Android, so can anyone see anything in my attribute processing code?

What's MyControl_header? I see you are not using it in the MyControl view in the XML. — Cristian, Aug 30 '11 at 17:42
Again, I don't see where you are using that custom resource in your layout xml. — Cristian, Aug 30 '11 at 18:27
The `` element in attrs.xml defines attributes for the MyControl control. The way you specify the identifier for the "header" attribute in code is `MyControl_header`. The symbol is defined when the R class is generated. — Turner Hayes, Aug 30 '11 at 18:52
Yes dude, but you are not telling android that MyControl_header has something to do with your MyControl view. — Cristian, Aug 30 '11 at 19:12
The association is made in the `` element (where it gives the name), I assume. — Turner Hayes, Aug 30 '11 at 19:15

score 2 · Accepted Answer · answered Aug 31 '11 at 14:25

Figured it out. It turns out, the attributes have to be namespaced in the XML; I put

<MyControl
    android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/drawer"
    header="@+id/header" content="@+id/drawerContent"...

but it needed to be

<MyControl xmlns:myPackage="http://schemas.android.com/apk/res/com.my.package"
    android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/drawer"
    myPackage:header="@+id/header" myPackage:content="@+id/drawerContent"

After I added those, it found the values just fine.

score 0 · Answer 2 · answered Aug 30 '11 at 17:53

0

Did you add the resources in values-> attrs.xml file?

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="MyControl">
    <attr name="headerId" format="integer" />
    </declare-styleable>
</resources>

answered Aug 30 '11 at 17:53

dcanh121

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Yeah, sorry, I forgot about that part. I've added it to the OP. I didn't include a header ID as an integer type, I included a header as a reference type. – Turner Hayes Aug 30 '11 at 18:00

getResourceId finds no ID in custom control

2 Answers2