Develop Reference

Android studio can not detect the source file in res/drawable

This is my code. I don't know how to post this image.
I tried to add source file for my ImageView. But it doesn't work. I tried to copy the path folder and it is still not work.

Solution - first problem
The resource name must start with a letter (not number).
Solution - second problem
Use just:
#drawable/039_cloud
instead
#drawable/039_cloud/039_cloud
so:
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/039_cloud" />
Android Studio
Android Studio is grouping same images, but for different DPIs.
When you choose Android view, you will have:
But when you will choose Project you will see "real" project structure:

Copy the image resource and paste it directly inside the drawable folder. Rename the image such that no number is included (e.g. image_thirty_nine.png). Then try this
<ImageView
android:id="#+id/image_id"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/image_thirty_nine" />
If you are till getting the same error after trying the above step, then try adding the image resource programmably
//ensure you assignn an id to your image
ImageView imageView = findViewById(R.id.image_id);
imageView.setImageResource(R.drawable.image_thirty_nine);
then run your code to see if it works

Failed to convert drawable into a drawable

I'm getting the error "Failed to convert #drawable/12234 into a drawable" where 12234 is my image name, that is placed inside the drawable folder.
I'm able to assign other images that are smaller, however when I try to assign this image it gives me an error.
Here is my code for my Imageview xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/imageView4"
android:layout_alignParentTop="true"
android:src="#drawable/12234"
android:adjustViewBounds="true"
android:longClickable="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentBottom="true" />

According to documentation drawables resources must satisfy the following:
File-based resource names must contain only lowercase a-z, 0-9, or _.
And also in your case it cannot be all numbers, it has to have at least one letter.

I solved the issue by renaming the image to have a character first.
Changed image name from 12234.jpg to r12234.jpg

In Adroid Studio's Design View, try just clicking the refresh icon, the one that looks like two curved arrows facing each other.
This worked for me - I didn't need to rename anything or restart my computer.
I'm running ver 1.5.1, Marshmallow, API 23.

I have been stumbling for many hours, read almost all answers on all questions but nothing worked. Finally, I have found a solution that worked.
What i did
Showed "drawable" in explorer
Replaced ALL ı's with i's (drawable-hdpı -> drawable-hdpi, renamed
all folders) Then the folders didn't appear in android studio
Replaced only 2 i's with ı's (drawable-hdpi -> drawable-hdpı, renamed
2 folders) Afterwards, all the images started to appear and finally
i was able to add images.

How to set background image for button in Android?

I Imported one image inside the drawable-mdpi, then implemented the image from button, but an error occurs no resource found here. How do I fix this issue?
I tried this:
main.xml
<Button
android:id="#+id/imageButtonSelector"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable-mdpi/button_focused_orange"/>

All drawables are compiled under a single resource name, i.e. drawable. Android automatically chooses from which folder to take the drawable depending on the screen size, and hence you do not need to specifically point it out. Also, hard coding Android to use resources from a particular folder kind of defeats the purpose of having multiple folders for Android to choose from. To solve this issue, simply change:
android:background="#drawable-mdbi/button_focused_orange"/>
To
android:background="#drawable/button_focused_orange"/>

Should be #drawable/button_focused_orange
Not #drawable-mdpi/button_focused_orange

Try to clean and rebuild your project.
If you are usuing Eclipse you can do this by clicking project -> clean and then project -> Build project

You don't have to mention -mdpi to add background images, simply use drawable only. Here is you revised code. Try this.
<Button
android:id="#+id/imageButtonSelector"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/button_focused_orange"/>

Best way to put vectorized symbols on button? Wingdings button title

Suppose I want to draw simple icon on the button surface. Let it be the cross or some letter.
What is the best way to do this? Can I use wingdings or webdings font on button?

As Android uses Unicode (utf-8) you can use any sign defined there, as long your font supports that. Just use copy and paste. The better solutions i think is using ImageButton using images from your drawables folder. This folder can be found in project/res/drawables or via Ecplipse Package-Explorer and you should use this to copy and paste your files in place (png, gif and jpg are supported)
In XML layout file a image is assigned the following way to an ImageButton
<ImageButton
android:id="#+id/imageButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_launcher" />
See also:
http://developer.android.com/reference/android/widget/ImageButton.html
http://developer.android.com/guide/topics/resources/providing-resources.html
http://developer.android.com/training/multiscreen/screendensities.html

Drawable not showing up

I have a fairly simple xml file that has an image button in it. The image shows up fine on the Graphical Layout xml designer, shows up fine when I run a development build, but as soon as I create the signed apk file and run it, the image no longer shows up. It's just an empty button. I can't think of a reason why, any ideas? The xml file looks like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/navigation_root"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="#+id/navigation_text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="5dp"
android:text="TextView"
android:textAppearance="?android:attr/textAppearanceLarge" />
<SeekBar
android:id="#+id/navigation_seekbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_weight="1"
android:padding="5dp" />
<LinearLayout
android:id="#+id/linearLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="5dp" >
<ImageButton
android:id="#+id/part_select_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/chapter_select" />
<Button
android:id="#+id/navigation_ok_button"
android:layout_width="75dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:text="#string/ok" />
<Button
android:id="#+id/navigation_cancel_button"
android:layout_width="75dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:text="#string/cancel" />
</LinearLayout>
</LinearLayout>
The image #drawable/chapter_select is a fairly small (41*41) png file that is in the res/drawable folder.

Seems like this is a bug with android, where sometimes the first image in the drawable folder doesn't show up. Added a dummy image called aaaa.png to the drawable folder and problem was solved. Found the answer here: ImageButton does not display a particular drawable

One of the reason is:
If you are using Vector file as a drawableLeft or drawableRight (or drawableStart or drawableEnd) in layout.xml, then you have to use androidx.appcompat.widget.AppCompatButton (formerly android.support.v7.widget.AppCompatButton) instead of Button.
Simple View like Button or Textview doesn't support Vector file as a drawableLeft or drawableRight (or drawableStart or drawableEnd) in my case.

Had the same issue and resolved it by removing all special characters. In my case it was dashes '-' in the filename:
background-720.png => background.png.

try to put the image in drawable-hdpi and drawable-mdpi folder
depends on what device you run you app , the image is searched in these folders...
But puting in drawable means that the image should be available everywhere, but somethimes (depends on your manifest settings) this could not be true, I mean you can turn of the compatibility mode.
also you can try dinamically at run time to set the image to the view
iv.setImageResource(R.drawable.somethig);

My situation was weird.Everything was correct until integrating FireBase Crash report to my Application.
I just added compile 'com.google.firebase:firebase-crash:11.0.1' & DrawableLeft vanished .When i went through the xml , noticed a warning (In lined below).
So added android:drawableStart & issue gone.
Still I am wondering about the relation of FireBase Crash reporting to the same.
Using left/right instead of start/end attributes Using Gravity#LEFT
and Gravity#RIGHT can lead to problems when a layout is rendered in
locales where text flows from right to left. Use Gravity#START and
Gravity#END instead.
Similarly, in XML gravity and layout_gravity attributes, use start
rather than left. For XML attributes such as paddingLeft and
layout_marginLeft, use paddingStart and layout_marginStart.
NOTE: If your minSdkVersion is less than 17, you should add both the
older left/right attributes as well as the new start/right attributes.
On older platforms, where RTL is not supported and the start/right
attributes are unknown and therefore ignored, you need the older
left/right attributes.
There is a separate lint check which catches that type of error.
(Note: For Gravity#LEFT and Gravity#START, you can use these constants
even when targeting older platforms, because the start bitmask is a
superset of the left bitmask. Therefore, you can use gravity="start"
rather than gravity="left|start".)

Check your image size. If you're using an unnecessarily large asset when actually deployed it might just not show despite looking correct in the designer.

Well ! in my case setting MinifyEnabled false and shrinkResources false is working fine now.
i was getting image from drawable. it was working pretty nice in debug version but after release version of apk it was showing sometime blank ImageView.
minifyEnabled false
shrinkResources true
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See the Screenshots
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Hope this may help anyone.

I had a similar problem where a drawable png was not showing up in Android Studio. Deleted the file and added it again in the drawable folder and it Worked for me.