The key must be an application-specific resource id

Why do I get this Exception?

05-18 20:29:38.044: ERROR/AndroidRuntime(5453): java.lang.IllegalArgumentException: The key must be an application-specific resource id.
05-18 20:29:38.044: ERROR/AndroidRuntime(5453):     at android.view.View.setTag(View.java:7704)
05-18 20:29:38.044: ERROR/AndroidRuntime(5453):     at com.mypkg.viewP.inflateRow(viewP.java:518)

the line in question is:

((Button) row.findViewById(R.id.btnPickContact)).setTag(TAG_ONLINE_ID,objContact.onlineid);

and I have it defined as:

private static final int TAG_ONLINE_ID = 1;

The reason you're not able to use setTag(int, Object) is because android require a pre-compiled unique id in the 'int' argument.

Try creating two unique entry in String.xml xml say, "firstname" & "secondname" & use them as below

imageView.setTag(R.string.firstname, "Abhishek");
imageView.setTag(R.string.lastname, "Gondalia");

I'm a little late to the party but I stumbled on this problem myself today and thought I'd give an answer as well. This answer will be a bit of a compilation of the other answers, but with a twist. First of all, the id, as has been pointed out by others, can NOT be a constant defined in your code (such as private static final int MYID = 123) or any other int that you define as a field somewhere.

The id has to be a precompiled unique id, just like the ones you get for strings that you put in values/strings.xml (ie R.string.mystring). Refer to http://developer.android.com/guide/topics/resources/available-resources.html and http://developer.android.com/guide/topics/resources/more-resources.html for more information.

My suggestion is that you create a new file called values/tags.xml and write:

    <resources xmlns:android="http://schemas.android.com/apk/res/android">
      <item name="TAG_ONLINE_ID" type="id"/>
    </resources>

I think it's better to create a separate file instead of putting it in strings.xml as EtienneSky suggested.

THIS WILL DO THE JOB...

If you just have 1 setTag in your class, you could use any int, maybe static final declared in the top.

The problem comes when you had 2 or more setTag's with different keys. I mean:

public static final int KEY_1 = 1;
public static final int KEY_2 = 2;
...
setTag(KEY_1, VALUE_1)
setTag(KEY_2, VALUE_2)
...

That scenario is wrong. You then need to add a value file called maybe ids.xml with the following:

<?xml version="1.0" encoding="utf-8"?>
<resources>
	<item type="id" name="resourceDrawable" />
	<item type="id" name="imageURI" />
</resources>

Then, in your class, call:

 ...
 setTag(R.id.resourceDrawable, VALUE_1)
 setTag(R.id.imageURI, VALUE_2)
 ...

The tag id must be unique so it wants it to be an id created in a resources file to guarantee uniqueness.

If the view will only contain one tag though you can just do

setTag(objContact.onlineid);

private static final int TAG_ONLINE_ID = 1 + 2 << 24;

should work. More info from ceph3us:

> The specified key should be an id declared in the resources of the > application to ensure it is unique Keys identified as belonging to the > Android framework or not associated with any package will cause an > IllegalArgumentException to be thrown.

from source:

public void setTag(int key, final Object tag) {
    // If the package id is 0x00 or 0x01, it's either an undefined package
    // or a framework id
    if ((key >>> 24) < 2) {
        throw new IllegalArgumentException("The key must be an application-specific "
                + "resource id.");
    }

    setKeyedTag(key, tag);
}

I've used viewHolder.itemTitleTextView.getId(). But you can also declare in your resources: <item type="id" name="conversation_thread_id"/>

you can use this :

private static final int TAG_ONLINE_ID = View.generateViewId() + 2 << 24;

for uniqness application-specific resource id

This works for me:

setTag(0xffffffff,objContact.onlineid);

The reason why you want to save the value by an id is, that you want to cover more than one value in this tag, right?
Here a more simple solution:
Let's say you want to save two values (Strings) into this tag: "firstname" and "lastname". You can save them both in one string, separated by semicolon:

v.setTag(firstname + ";" + lastname);

... and access them by splitting them into an string array:

String[] data = v.getTag().toString().split(";");
System.out.println(data[0]) //firstname
System.out.println(data[1]) //lastname

Here is a simple workaround that works for me:

int tagKey = "YourSimpleKey".hashCode();

myView.setTag(tagKey, "MyTagObject");

the important clue here is to call .hashCode(); on the String