Format attribute value "android:drawable" not valid

Question

I'm trying to create custom attributes to my button but I dont know which format I must use to images in attributes declaration...

<?xml version="1.0" encoding="utf-8"?> <resources>      <declare-styleable name="TCButton">         <attr name="Text" format="string"/>         <attr name="BackgroundImage" format="android:drawable"  />     </declare-styleable>   </resources> 

Error is in the format="android:drawable"...

Answer 1

You can use format="integer", the resource id of the drawable, and AttributeSet.getDrawable(...).

Here is an example.

Declare the attribute as integer in res/values/attrs.xml:

<resources>     <declare-styleable name="MyLayout">         <attr name="icon" format="integer" />     </declare-styleable> </resources> 

Set the attribute to a drawable id in your layout:

<se.jog.MyLayout     android:layout_width="wrap_content"     android:layout_height="wrap_content"      myapp:icon="@drawable/myImage" /> 

Get the drawable from the attribute in your custom widget component class:

ImageView myIcon; //... TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MyLayout); Drawable drawable = a.getDrawable(R.styleable.MyLayout_icon); if (drawable != null)     myIcon.setBackgroundDrawable(drawable); 

To see all options possible check the android src here

Answer 2

I think it will be better to use it as a simple reference:

<declare-styleable name="TCButton">         <attr name="customText" format="string"/>         <attr name="backgroundImage" format="reference"  /> </declare-styleable> 

And set it in your xml like this:

<your.package.name.TCButton     android:layout_width="wrap_content"     android:layout_height="wrap_content"      custom:customText="Some custom text"     custom:backgroundImage="@drawable/myImage" /> 

And in your class set the attributes like this:

public TCButton(Context context, AttributeSet attrs) {     super(context, attrs);     TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.MembershipItemView, 0, 0);      String customText;     Drawable backgroundImage;     try {         customText = a.getString(R.styleable.TCButton_customText);         backgroundImage = a.getDrawable(R.styleable.TCButton_backgroundImage);     } finally {         a.recycle();     }      if(!TextUtils.isEmpty(customText)) {       ((TextView)findViewById(R.id.yourTextView)).setText(customText);     }      if(null != backgroundImage) {                             ((ImageView)findViewById(R.id.yourImageView)).setBackgroundDrawable(backgroundImage);     } } 

PS: Don't forget to add this line for the root element of the layout you are using your custom view in

xmlns:custom="http://schemas.android.com/apk/res-auto" 

If you don't set this, you won't be able to access your custom attributes.