Android AutoCompleteTextView Control

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A AutoCompleteTextView is a view that is similar to EditText, except that it shows a list of completion suggestions automatically while the user is typing. The list of suggestions is displayed in drop down menu. The user can choose an item from there to replace the content of edit box with.

AutoCompleteTextView Attributes

Following are the important attributes related to AutoCompleteTextView control. You can check Android official documentation for complete list of attributes and related methods which you can use to change these attributes are run time.

AttributeDescription
android:completionHintThis defines the hint displayed in the drop down menu.
android:completionHintViewThis defines the hint view displayed in the drop down menu.
android:completionThresholdThis defines the number of characters that the user must type before completion suggestions are displayed in a drop down menu.
android:dropDownAnchorThis is the View to anchor the auto-complete dropdown to.
android:dropDownHeightThis specifies the basic height of the dropdown.
android:dropDownHorizontalOffsetThe amount of pixels by which the drop down should be offset horizontally.
android:dropDownSelectorThis is the selector in a drop down list.
android:dropDownVerticalOffsetThe amount of pixels by which the drop down should be offset vertically.
android:dropDownWidthThis specifies the basic width of the dropdown.
android:popupBackgroundThis sets the background.

Example

This example will take you through simple steps to show how to create your own Android application using Linear Layout and AutoCompleteTextView.

StepDescription
1You will use Eclipse IDE to create an Android application and name it as GUIDemo3 under a package com.example.guidemo3 as explained in the Hello World Example chapter.
2Modify src/MainActivity.java file to add a click event.
2Modify the detault content of res/layout/activity_main.xml file to include Android UI control.
3Define required constants in res/values/strings.xml file
4Run the application to launch Android emulator and verify the result of the changes done in the application.

Following is the content of the modified main activity file src/com.example.guidemo3/MainActivity.java. This file can include each of the fundamental lifecycle methods.

package com.example.guidemo3;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;

public class MainActivity extends Activity {
	
   AutoCompleteTextView autocompletetextview;

   String[] arr = { "MS SQL SERVER", "MySQL", "Oracle" };

   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);

      autocompletetextview = (AutoCompleteTextView)             
      findViewById(R.id.autoCompleteTextView1);

      ArrayAdapter adapter = new ArrayAdapter  
      (this,android.R.layout.select_dialog_item, arr);

      autocompletetextview.setThreshold(1);
      autocompletetextview.setAdapter(adapter);	
   }

   @Override
   public boolean onCreateOptionsMenu(Menu menu) {
      /* Inflate the menu; this adds items to the action bar if
      it is present */
      getMenuInflater().inflate(R.menu.main, menu);
      return true;
   }
}

Following will be the content of res/layout/activity_main.xml file:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="25dp"
        android:text="@string/example_autocompletetextview" /
        >

    <AutoCompleteTextView
        android:id="@+id/autoCompleteTextView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView2"
        android:layout_below="@+id/textView2"
        android:layout_marginTop="54dp"
        android:ems="10" />

</RelativeLayout>

Following will be the content of res/values/strings.xml to define these new constants:

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">GUIDemo3</string>
    <string name="action_settings">Settings</string>
    <string name="example_autocompletetextview">Example   
    showing AutoCompleteTextView</string>

</resources>

Following is the default content of AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.guidemo3"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.guidemo3.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Let's try to run your GUIDemo3 application. I assume you had created your AVD while doing environment setup. To run the app from Eclipse, open one of your project's activity files and click Run Eclipse Run Icon icon from the toolbar. Eclipse installs the app on your AVD and starts it and if everything is fine with your setup and application, it will display following Emulator window:

Android AutoCompleteTextView Control

The following screen will appear after "m" will be typed in AutoCompleteTextView:

Android AutoCompleteTextView Control

Exercise:

I will recommend to try above example with different attributes of AutoCompleteTextView in Layout XML file as well at programming time to have different look and feel of the AutoCompleteTextView. Try to make it editable, change to font color, font family, width, textSize etc and see the result. You can also try above example with multiple AutoCompleteTextView controls in one activity.



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