ANDROID: Resources
There are many more items which you use to build a good Android application. Apart from coding for the application, you take care of various other resources like static content that your code uses, such as bitmaps, colors, layout definitions, user interface strings, animation instructions, and more. These resources are always maintained separately in various sub-directories under res/ directory of the project.
This tutorial will explain you how you can organize your application resources, specify alternative resources and access them in your applications.
Organize resource in Android Studio
Masih banyak lagi item yang Anda gunakan untuk membangun aplikasi Android yang bagus. Selain pengkodean untuk aplikasi, Anda menangani berbagai sumber daya lain seperti konten statis yang digunakan kode Anda, seperti bitmap, warna, definisi tata letak, string antarmuka pengguna, instruksi animasi, dan banyak lagi. Sumber daya ini selalu dipelihara secara terpisah di berbagai sub-direktori di bawah direktori res/ proyek.
Tutorial ini akan menjelaskan bagaimana Anda dapat mengatur sumber daya aplikasi Anda, menentukan sumber daya alternatif dan mengaksesnya di aplikasi Anda.
Atur sumber daya di Android Studio
MyProject/
app/
manifest/
AndroidManifest.xml
java/
MyActivity.java
res/
drawable/
icon.png
layout/
activity_main.xml
info.xml
values/
strings.xml
| Sr.No. | Directory | Resource Type |
|---|---|---|
| 1 | anim/ | XML files that define property animations. They are saved in res/anim/ folder and accessed from the R.anim class. |
| 2 | color/ | XML files that define a state list of colors. They are saved in res/color/ and accessed from the R.color class. |
| 3 | drawable/ | Image files like .png, .jpg, .gif or XML files that are compiled into bitmaps, state lists, shapes, animation drawable. They are saved in res/drawable/ and accessed from the R.drawable class. |
| 4 | layout/ | XML files that define a user interface layout. They are saved in res/layout/ and accessed from the R.layout class. |
| 5 | menu/ | XML files that define application menus, such as an Options Menu, Context Menu, or Sub Menu. They are saved in res/menu/ and accessed from the R.menu class. |
| 6 | raw/ | Arbitrary files to save in their raw form. You need to call Resources.openRawResource() with the resource ID, which is R.raw.filename to open such raw files. |
| 7 | values/ | XML files that contain simple values, such as strings, integers, and colors. For example, here are some filename conventions for resources you can create in this directory −
|
| 8 | xml/ | Arbitrary XML files that can be read at runtime by calling Resources.getXML(). You can save various configuration files here which will be used at run time. |
Alternative Resources
Your application should provide alternative resources to support specific device configurations. For example, you should include alternative drawable resources ( i.e.images ) for different screen resolution and alternative string resources for different languages. At runtime, Android detects the current device configuration and loads the appropriate resources for your application.
To specify configuration-specific alternatives for a set of resources, follow the following steps −
Create a new directory in res/ named in the form <resources_name>-<config_qualifier>. Here resources_name will be any of the resources mentioned in the above table, like layout, drawable etc. The qualifier will specify an individual configuration for which these resources are to be used. You can check official documentation for a complete list of qualifiers for different type of resources.
Save the respective alternative resources in this new directory. The resource files must be named exactly the same as the default resource files as shown in the below example, but these files will have content specific to the alternative. For example though image file name will be same but for high resolution screen, its resolution will be high.
Below is an example which specifies images for a default screen and alternative images for high resolution screen.
Aplikasi Anda harus menyediakan sumber daya alternatif untuk mendukung konfigurasi perangkat tertentu. Misalnya, Anda harus menyertakan sumber daya alternatif yang dapat digambar (yaitu gambar) untuk resolusi layar yang berbeda dan sumber daya string alternatif untuk bahasa yang berbeda. Saat waktu proses, Android mendeteksi konfigurasi perangkat saat ini dan memuat sumber daya yang sesuai untuk aplikasi Anda.
Untuk menentukan alternatif konfigurasi khusus untuk satu set sumber daya, ikuti langkah-langkah berikut -
Buat direktori baru di res/ bernama dalam bentuk <resources_name>-<config_qualifier>. Di sini resources_name akan menjadi salah satu sumber daya yang disebutkan dalam tabel di atas, seperti tata letak, dapat digambar, dll. Kualifikasi akan menentukan konfigurasi individual untuk mana sumber daya ini akan digunakan. Anda dapat memeriksa dokumentasi resmi untuk daftar lengkap kualifikasi untuk berbagai jenis sumber daya.
Simpan masing-masing sumber daya alternatif di direktori baru ini. File sumber daya harus dinamai sama persis dengan file sumber daya default seperti yang ditunjukkan pada contoh di bawah ini, tetapi file ini akan memiliki konten khusus untuk alternatifnya. Misalnya meskipun nama file gambar akan sama tetapi untuk layar resolusi tinggi, resolusinya akan tinggi.
Di bawah ini adalah contoh yang menentukan gambar untuk layar default dan gambar alternatif untuk layar resolusi tinggi.
MyProject/
app/
manifest/
AndroidManifest.xml
java/
MyActivity.java
res/
drawable/
icon.png
background.png
drawable-hdpi/
icon.png
background.png
layout/
activity_main.xml
info.xml
values/
strings.xml
Below is another example which specifies layout for a default language and alternative layout for Arabic language.
Di bawah ini adalah contoh lain yang menentukan tata letak untuk bahasa default dan tata letak alternatif untuk bahasa Arab.
MyProject/
app/
manifest/
AndroidManifest.xml
java/
MyActivity.java
res/
drawable/
icon.png
background.png
drawable-hdpi/
icon.png
background.png
layout/
activity_main.xml
info.xml
layout-ar/
main.xml
values/
strings.xml
Accessing Resources
During your application development you will need to access defined resources either in your code, or in your layout XML files. Following section explains how to access your resources in both the scenarios −
Selama pengembangan aplikasi Anda, Anda perlu mengakses sumber daya yang ditentukan baik dalam kode Anda, atau dalam file XML tata letak Anda. Bagian berikut menjelaskan cara mengakses sumber daya Anda di kedua skenario
Accessing Resources in Code
When your Android application is compiled, a R class gets generated, which contains resource IDs for all the resources available in your res/ directory. You can use R class to access that resource using sub-directory and resource name or directly resource ID.
Saat aplikasi Android Anda dikompilasi, kelas R akan dibuat, yang berisi ID sumber daya untuk semua sumber daya yang tersedia di direktori res/ Anda. Anda dapat menggunakan kelas R untuk mengakses sumber daya tersebut menggunakan sub-direktori dan nama sumber daya atau ID sumber daya secara langsung.−
Example
To access res/drawable/myimage.png and set an ImageView you will use following code −
Untuk mengakses res/drawable/myimage.png dan mengatur ImageView, Anda akan menggunakan kode berikut
ImageView imageView = (ImageView) findViewById(R.id.myimageview); imageView.setImageResource(R.drawable.myimage);
Here first line of the code make use of R.id.myimageview to get ImageView defined with id myimageview in a Layout file. Second line of code makes use of R.drawable.myimage to get an image with name myimage available in drawable sub-directory under /res.
Di sini baris pertama kode menggunakan R.id.myimageview untuk mendapatkan ImageView didefinisikan dengan id myimageview dalam file Layout. Baris kode kedua menggunakan R.drawable.myimage untuk mendapatkan gambar dengan nama myimage yang tersedia di sub-direktori drawable di bawah /res.
Example
Consider next example where res/values/strings.xml has following definition −
<?xml version="1.0" encoding="utf-8"?> <resources> <string name="hello">Hello, World!</string> </resources>
Now you can set the text on a TextView object with ID msg using a resource ID as follows −
TextView msgTextView = (TextView) findViewById(R.id.msg); msgTextView.setText(R.string.hello);
Example
Consider a layout res/layout/activity_main.xml with the following definition −
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <TextView android:id="@+id/text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello, I am a TextView" /> <Button android:id="@+id/button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello, I am a Button" /> </LinearLayout>
This application code will load this layout for an Activity, in the onCreate() method as follows −
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
Accessing Resources in XML
Consider the following resource XML res/values/strings.xml file that includes a color resource and a string resource −
<?xml version="1.0" encoding="utf-8"?> <resources> <color name="opaque_red">#f00</color> <string name="hello">Hello!</string> </resources>
Now you can use these resources in the following layout file to set the text color and text string as follows −
<?xml version="1.0" encoding="utf-8"?> <EditText xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:textColor="@color/opaque_red" android:text="@string/hello" />
Now if you will go through previous chapter once again where I have explained Hello World! example, and I'm sure you will have better understanding on all the concepts explained in this chapter. So I highly recommend to check previous chapter for working example and check how I have used various resources at very basic level.