Easier way to get view's Id (string) by its Id (int)

Question

I have 24 buttons in my layout, all these buttons do something similar so I want to create a generic function. But first I need to know the name (xml id) of he button.

This the XML code of the button:

  <Button
      android:id="@+id/add_04"
      android:layout_width="42dp"
      android:layout_height="wrap_content"
      android:layout_gravity="center"
      android:layout_marginLeft="15dp"
      android:background="@xml/zbuttonshape"
      android:onClick="onClick"
      android:text="@string/mas" />

I set android:onClick="onClick" for all the buttons.

In my activity I've create a new function onClick:

This the code I've tried:

public void onClick(View v) {
        String name = v.getContext().getString(v.getId());
        String name2 = context.getString(v.getId());
        String name3 = getString(v.getId());
        String name4 = getResources().getString(v.getId()); 
}

But when I try to get the name (in this case "add_04") I always get "false".

Finally I've found a solution with the following code:

import java.lang.reflect.Field;

String name5 = null;
Field[] campos = R.id.class.getFields();
for(Field f:campos){
     try{
        if(v.getId()==f.getInt(null)){
            name5 = f.getName();
            break;
        }
       }
       catch(Exception e){
        e.printStackTrace();
    }
}

Is there an easier way to get this ID?

Why do you need to get string id? – Mikita Belahlazau Feb 01 '13 at 14:02 — Mikita Belahlazau, Feb 01 '13 at 14:02

score 165 · Answer 1 · edited Jun 05 '19 at 14:11

165

like this:

/**
 * @return "[package]:id/[xml-id]"
 * where [package] is your package and [xml-id] is id of view
 * or "no-id" if there is no id
 */
public static String getId(View view) {
    if (view.getId() == View.NO_ID) return "no-id";
    else return view.getResources().getResourceName(view.getId());
}

I use this in view constructors to make more meaningful TAGs

edited Jun 05 '19 at 14:11

Ωmega

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answered Aug 05 '13 at 20:58

gadget

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14

came here looking for a way to debug, this answer delivered – jmaculate Oct 29 '14 at 22:55
1

sometime view no id ,this way will get `NotFoundException("Unable to find resource ID #0x" + Integer.toHexString(resid));` exception – Carl Apr 28 '17 at 09:40
2

There is a constant for `0xffffffff` called `View.NO_ID` (https://developer.android.com/reference/android/view/View.html#NO_ID) – Michael Osofsky Apr 17 '19 at 07:32
If misused the getResourceName() method can crash the application when the id is not found. – luiscosta Mar 22 '22 at 11:57

Seva Alekseyev · Accepted Answer · 2021-09-18T20:59:39.343

43

The approach is misguided to begin with. If you want to associate a piece of arbitrary data (e. g. a string) with a view, that's what tag is for. The ID is numeric and it better stay that way. A word of caution though, tags are not unique in Android, watch for accidental tag collisions within the same view tree.

EDIT much later: the OP's issue was a case of an XY problem. That said, the question title alone is a legitimate question in its own right.

edited Sep 18 '21 at 20:59

answered Feb 01 '13 at 14:08

Seva Alekseyev

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Thanks, that what I need. With the property tag I can do it. String name = v.getTag().toString(); – Richal Feb 02 '13 at 10:44
1

Android Docs: Unlike IDs, tags are not used to identify views. Tags are essentially an extra piece of information that can be associated with a view. They are most often used as a convenience to store data related to views in the views themselves rather than by putting them in a separate structure. – Jeffrey Nov 06 '18 at 23:04
6

view.getResources().getResourceName(view.getId()); Return the full name for a given resource identifier. This name is a single string of the form package:type/id". – Jeffrey Nov 06 '18 at 23:12
1

getResources().getResourceEntryName(view.getId()); Returns the string representation of the view id only. – Jeffrey Nov 06 '18 at 23:16

Blackbelt · Answer 3 · 2016-09-11T11:50:36.807

32

Edit:

You have to use

getResources().getResourceEntryName(int resid);

If you want to retrieve the entry name associated to a resId

or

You can use getIdentifier() to retriece a resource identifier for the given resource name.

For instance:

int id = this.getResources().getIdentifier("yourtext", "string", this.getPackageName());

edited Sep 11 '16 at 11:50

answered Feb 01 '13 at 14:01

Blackbelt

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Doesn't work for me - I get 'NullPointerException' is it always the same package name? – GyRo Mar 01 '15 at 13:34
1

@GyRo where do you get a `NPE`? Where are you executing that line of code? Are you trying to retrieve a `String` id ? – Blackbelt Mar 01 '15 at 13:44
The case can be found in the answer here: http://stackoverflow.com/questions/28729067/android-increment-button-in-loop-to-setvisibility/28729614#28729614 – GyRo Mar 02 '15 at 07:20
1

You are looking in the wrong class. Use "id" in place of "string" – Blackbelt Mar 02 '15 at 07:31
What is `yourtext` supposed to be? – IgorGanapolsky Sep 15 '15 at 17:15
@Ganapolsky is the value of the field "name", for which you want to retrieve the id – Blackbelt Sep 15 '15 at 17:18
I think you misunderstood the question. It is the other way around. OP has the id, and wants to get the field name – BeniBela Sep 11 '16 at 11:20
5

This should be the accepted answer, why? if I have 50 buttons in my application, then I have to set tag for each one and this is not the best approach. However, I can use `getResources().getResourceEntryName(int resid);` to easily get view entry id. +1 for providing this solution – blueware Nov 23 '16 at 10:08

score 19 · Answer 4 · answered Feb 01 '13 at 14:02

19

You can check id of each button such way:

public void onClick(View v) {
    switch (v.getId()) {
    case R.id.add_04:
        Toast.makeText(MainActivity.this, "1", Toast.LENGTH_LONG).show();
        break;
    case R.id.add_05:
        Toast.makeText(MainActivity.this, "2", Toast.LENGTH_LONG).show();
        break;
    }
}

answered Feb 01 '13 at 14:02

dilix

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This is what i want! – tomwang1013 Nov 02 '17 at 05:54

score 10 · Answer 5 · answered Jul 16 '18 at 07:05

   Use this Approach to get View Id by Programming .
  <TextView
    android:id="@+id/tv"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Hello World!"
    />


    String id=getResources().getResourceEntryName(textView.getId());
    Toast.makeText(this,id,Toast.LENGTH_LONG).show();

You will get Result ; tv

score 7 · Answer 6 · answered May 13 '14 at 10:05

You can put this toString() inside an Android View, it will return the String resource Id.

@Override
public String toString() {

    Context context;
    Resources r = null;

    context = getContext();

    if (context != null) {
        r = context.getResources();
    }

    String entryName = null;

    if (r != null)
        entryName = r.getResourceEntryName(getId());

    return entryName;
}

score 3 · Answer 7 · answered Dec 17 '17 at 15:20

3

Kotlin version (from @gadget) as view extension:

val View.stringId: String
    get() {
        return if (this.id == -0x1)
            "no-id"
        else
            this.resources.getResourceName(this.id)
    }

answered Dec 17 '17 at 15:20

Gabriel

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Nice. It's even terser if you use assignment syntax and omit 'this' and 'return'. `val View.name: String get() = if (this.id == -0x1) "no-id" else resources.getResourceEntryName(id) ?: "error-getting-name"` – Patrick Steiger Jun 26 '18 at 17:14

score 2 · Answer 8 · answered Jul 19 '19 at 06:18

It's a late answer but may useful someone looking out for a way to get the resource id (int) for any view / drawable / String programmatic.

image from res/drawable

int resID = getResources().getIdentifier("my_image", 
            "drawable", getPackageName());

view based on resource name

int resID = getResources().getIdentifier("my_resource", 
            "id", getPackageName());

string

int resID = getResources().getIdentifier("my_string", 
            "string", getPackageName());

score 0 · Answer 9 · answered Jan 27 '22 at 10:26

The answer by @King of Masses is great. Here is my in Kotlin:

image from res/drawable

val viewId = context.resources.getIdentifier("my_image", "drawable", context.packageName)

view based on resource name

val viewId = context.resources.getIdentifier("my_textview_id", "id", context.packageName)

string

val viewId = context.resources.getIdentifier("my_string", "string", context.packageName)

Layout

val viewId = context.resources.getIdentifier("my_custom_layout", "layout", context.packageName)

Easier way to get view's Id (string) by its Id (int)

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