What does Android Spinner refer to?<\/h2>\n
Spinners are similar to drop-down menus that contain a selection of items. Once a value is chosen, the Spinner reverts back to its default state with the selected value. However, starting from Android 3.0, it is no longer possible to display a prompt as the default state in the Spinner. Instead, the first item in the list is shown. A Spinner in Android<\/a> functions similarly to a phone charger being connected to an electricity board using an adapter. The adapter allows the Spinner (phone) to be loaded with data, just like how it provides electricity to the phone. In this case, the adapter specifies both the data and the layout for the items to be loaded in the Spinner.<\/p>\n The AdapterView.onItemSelectedListener interface is utilized for invoking the callbacks of the Spinner click event. It comprises of two methods:<\/p>\n In the upcoming portion, we will establish a fresh Android Studio Project and integrate Spinners into our Application. We will modify the designs and gain proficiency in managing various situations.<\/p>\n Below is the code provided for the activity_main.xml layout file.<\/p>\n Currently, it holds only one Spinner where android:spinnerMode can either be set as dialog or dropdown.<\/p>\n To display prompts, set the spinnerMode value to dialog.<\/p>\n Below is the code for spinner_right_aligned.xml.<\/p>\n Here’s the provided code for the MainActivity.kt class.<\/p>\n Key ideas:<\/p>\n We have now generated another Spinner using programming code that loads the layouts from the spinner_right_aligned.xml file.<\/p>\n To avoid the triggering of the OnItemSelected methods of the Spinner when the Activity is created, use setSelection(0, false).<\/p>\n – How does it function? The Activity is informed that the initial spinner item has been selected by the setSelection() method. This statement must be placed before onItemSelectedListener = this. To set the background color of the dropdown list, setPopupBackgroundResource is utilized. In the onItemSelected function, a Toast is triggered for the corresponding spinner item using the when statement. Thanks to Kotlin and functions with default values, we have minimized the lengthy Toast call.<\/p>\n More tutorials<\/p>\n Creating an Android ProgressBar utilizing Kotlin.(Opens in a new browser tab)<\/span><\/a><\/p>\n Using Kotlin Android SharedPreferences(Opens in a new browser tab)<\/span><\/a><\/p>\n A class in Kotlin that is sealed.(Opens in a new browser tab)<\/span><\/a><\/p>\n One example of Spring REST XML and JSON(Opens in a new browser tab)<\/span><\/a><\/p>\nEvents for Spinner Callback<\/h2>\n
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Project in Kotlin for an Android Spinner.<\/h2>\n
![\"android](\"https:\/\/cdn.silicloud.com\/blog-img\/blog\/img\/655dc3f6cdcf9b67579ff677\/10-0.png\" "\\"\\"")
<\/div>\n1. XML Code for Layout Design<\/h3>\n
<?xml version=\"1.0\" encoding=\"utf-8\"?>\r\n<LinearLayout xmlns:android=\"http:\/\/schemas.android.com\/apk\/res\/android\"\r\n xmlns:tools=\"http:\/\/schemas.android.com\/tools\"\r\n android:layout_width=\"match_parent\"\r\n android:layout_height=\"match_parent\"\r\n android:orientation=\"vertical\"\r\n android:id=\"@+id\/linearLayout\"\r\n android:gravity=\"center\"\r\n tools:context=\".MainActivity\">\r\n\r\n <Spinner\r\n android:id=\"@+id\/mySpinner\"\r\n android:layout_width=\"match_parent\"\r\n android:spinnerMode=\"dialog\"\r\n android:layout_height=\"wrap_content\" \/>\r\n\r\n<\/LinearLayout>\r\n<\/code><\/pre>\n2. XML Code for a Spinner<\/h3>\n
<?xml version=\"1.0\" encoding=\"utf-8\"?>\r\n<TextView xmlns:android=\"http:\/\/schemas.android.com\/apk\/res\/android\"\r\n android:id=\"@+id\/textView\"\r\n android:layout_width=\"match_parent\"\r\n android:layout_height=\"wrap_content\"\r\n android:gravity=\"end\"\r\n android:padding=\"15dp\"\r\n android:textAlignment=\"gravity\"\r\n android:textColor=\"@color\/colorPrimary\"\r\n android:textSize=\"16sp\"\r\n \/>\r\n\r\n<\/code><\/pre>\nOption 1: Kotlin Code for the MainActivity<\/h3>\n
package net.androidly.androidspinnerkotlin\r\n\r\nimport android.content.Context\r\nimport android.support.v7.app.AppCompatActivity\r\nimport android.os.Bundle\r\nimport android.view.Gravity\r\nimport android.view.View\r\nimport android.widget.*\r\nimport kotlinx.android.synthetic.main.activity_main.*\r\n\r\nclass MainActivity : AppCompatActivity(), AdapterView.OnItemSelectedListener {\r\n\r\n\r\n var languages = arrayOf(\"Java\", \"PHP\", \"Kotlin\", \"Javascript\", \"Python\", \"Swift\")\r\n val NEW_SPINNER_ID = 1\r\n\r\n override fun onCreate(savedInstanceState: Bundle?) {\r\n super.onCreate(savedInstanceState)\r\n setContentView(R.layout.activity_main)\r\n\r\n\r\n var aa = ArrayAdapter(this, android.R.layout.simple_spinner_item, languages)\r\n aa.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)\r\n\r\n with(mySpinner)\r\n {\r\n adapter = aa\r\n setSelection(0, false)\r\n onItemSelectedListener = this@MainActivity\r\n prompt = \"Select your favourite language\"\r\n gravity = Gravity.CENTER\r\n\r\n }\r\n\r\n val spinner = Spinner(this)\r\n spinner.id = NEW_SPINNER_ID\r\n\r\n val ll = LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT)\r\n\r\n ll.setMargins(10, 40, 10, 10)\r\n linearLayout.addView(spinner)\r\n\r\n aa = ArrayAdapter(this, R.layout.spinner_right_aligned, languages)\r\n aa.setDropDownViewResource(R.layout.spinner_right_aligned)\r\n\r\n with(spinner)\r\n {\r\n adapter = aa\r\n setSelection(0, false)\r\n onItemSelectedListener = this@MainActivity\r\n layoutParams = ll\r\n prompt = \"Select your favourite language\"\r\n setPopupBackgroundResource(R.color.material_grey_600)\r\n\r\n }\r\n\r\n }\r\n\r\n override fun onNothingSelected(parent: AdapterView<*>?) {\r\n showToast(message = \"Nothing selected\")\r\n }\r\n\r\n override fun onItemSelected(parent: AdapterView<*>?, view: View?, position: Int, id: Long) {\r\n\r\n when (view?.id) {\r\n 1 -> showToast(message = \"Spinner 2 Position:${position} and language: ${languages[position]}\")\r\n else -> {\r\n showToast(message = \"Spinner 1 Position:${position} and language: ${languages[position]}\")\r\n }\r\n }\r\n }\r\n\r\n private fun showToast(context: Context = applicationContext, message: String, duration: Int = Toast.LENGTH_LONG) {\r\n Toast.makeText(context, message, duration).show()\r\n }\r\n}\r\n<\/code><\/pre>\n\n
The output of the Kotlin app for Spinner.<\/h3>\n
![\"android](\"https:\/\/cdn.silicloud.com\/blog-img\/blog\/img\/655dc3f6cdcf9b67579ff677\/28-0.gif\" "\\"\\"")
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