You can force Android to hide the virtual keyboard using the InputMethodManager, calling hideSoftInputFromWindow, passing in the token of the window containing your focused view.

// Check if no view has focus:
View view = this.getCurrentFocus();
if (view != null) {  
    InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
}

This will force the keyboard to be hidden in all situations. In some cases you will want to pass in InputMethodManager.HIDE_IMPLICIT_ONLY as the second parameter to ensure you only hide the keyboard when the user didn't explicitly force it to appear (by holding down menu).

Note: If you want to do this in Kotlin, use: context?.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager

Kotlin Syntax

// Check if no view has focus:
 val view = this.currentFocus
 view?.let { v ->
  val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager 
  imm?.let { it.hideSoftInputFromWindow(v.windowToken, 0) }
 }

just make common method for whole application in BaseActivity and BaseFragment

in onCreate() initialize inputMethodManager

inputMethodManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);

make this methods to hide & show keyboard

public void hideKeyBoard(View view) {
     if (view != null) {
         inputMethodManager.hideSoftInputFromWindow(view.getWindowToken(), 0);
      }
 }

public void showKeyboard(View view, boolean isForceToShow) {
      if (isForceToShow)
         inputMethodManager.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0);
      else if (view != null)
           inputMethodManager.showSoftInput(view, 0);
}

Below code will help you to make generic function that can be call from anywhere.

import android.app.Activity
import android.content.Context
import android.support.design.widget.Snackbar
import android.view.View
import android.view.inputmethod.InputMethodManager

public class KeyboardHider {
    companion object {

        fun hideKeyboard(view: View, context: Context) {
            val inputMethodManager = context.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
            inputMethodManager.hideSoftInputFromWindow(view.windowToken, 0)
        }

    }

}

Call Above method from anywhere using one single line of code.

CustomSnackbar.hideKeyboard(view, [email protected])

view could be anything for example root layout of an activity.

there are two ways to do so...

method 1:in manifest file

define the line **android:windowSoftInputMode="adjustPan|stateAlwaysHidden"** of code in your manifest.xml file as below...

<activity
            android:name="packagename.youactivityname"
            android:screenOrientation="portrait"
            android:windowSoftInputMode="adjustPan|stateAlwaysHidden" />

Method 2 : in Activity or Java class

 if(getCurrentFocus()!=null) {
            InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE)`enter code here`;
            inputMethodManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), 0);
        }

it will [email protected]

Hi This is simple if you are working with Kotlin i belive you can easily convert the code to Java too first in your activity use this function when your activity is load for example in the onCreate() call it.

fun hideKeybord (){
val inputManager = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
if (inputManager.isAcceptingText){
    inputManager.hideSoftInputFromWindow(currentFocus.windowToken, 0)
}

}

as i mentiond call this Function in your onCreate() methode then add this android:windowSoftInputMode="stateAlwaysHidden" line to your activity in manafest.xml file Like this...

<activity
    android:name=".Activity.MainActivity"
    android:label="@string/app_name"
    android:theme="@style/AppTheme.NoActionBar"
    android:windowSoftInputMode="stateAlwaysHidden">

If you use Kotlin for developing your application, it's really easy to do.

Add this extensions functions:

For Activity:

fun Activity.hideKeyboard() {
    val inputManager = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    val view = currentFocus
    if (view != null) {
        inputManager.hideSoftInputFromWindow(view.windowToken, InputMethodManager.HIDE_NOT_ALWAYS)
    }
}

For Fragment:

fun Fragment.hideKeyboard() {
    activity?.let {
        val inputManager = it.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
        val view = it.currentFocus
        if (view != null) {
            inputManager.hideSoftInputFromWindow(view.windowToken, InputMethodManager.HIDE_NOT_ALWAYS)
        }
    }
}

Now you can simple call in your Fragment or Activity:

 hideKeyboard()

protected void hideSoftKeyboard(EditText input) {
    InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.hideSoftInputFromWindow(input.getWindowToken(), 0);    
}

For the kotlin users out there here is a kotlin extension method that has worked for my use cases:

fun View.hideKeyboard() {
    val imm = this.context.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
    imm.hideSoftInputFromWindow(windowToken, 0)
}

put it in a file called ViewExtensions (or what have you) and call it on your views just like a normal method.

To help clarify this madness, I'd like to begin by apologizing on behalf of all Android users for Google's downright ridiculous treatment of the soft keyboard. The reason there are so many answers, each different, for the same simple question because this API, like many others in Android, is horribly designed. I can think of no polite way to state it.

I want to hide the keyboard. I expect to provide Android with the following statement: Keyboard.hide(). The end. Thank you very much. But Android has a problem. You must use the InputMethodManager to hide the keyboard. OK, fine, this is Android's API to the keyboard. BUT! You are required to have a Context in order to get access to the IMM. Now we have a problem. I may want to hide the keyboard from a static or utility class that has no use or need for any Context. or And FAR worse, the IMM requires that you specify what View (or even worse, what Window) you want to hide the keyboard FROM.

This is what makes hiding the keyboard so challenging. Dear Google: When I'm looking up the recipe for a cake, there is no RecipeProvider on Earth that would refuse to provide me with the recipe unless I first answer WHO the cake will be eaten by AND where it will be eaten!!

This sad story ends with the ugly truth: to hide the Android keyboard, you will be required to provide 2 forms of identification: a Context and either a View or a Window.

I have created a static utility method which can do the job VERY solidly, provided you call it from an Activity.

public static void hideKeyboard(Activity activity) {
    InputMethodManager imm = (InputMethodManager) activity.getSystemService(Activity.INPUT_METHOD_SERVICE);
    //Find the currently focused view, so we can grab the correct window token from it.
    View view = activity.getCurrentFocus();
    //If no view currently has focus, create a new one, just so we can grab a window token from it
    if (view == null) {
        view = new View(activity);
    }
    imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
}

Be aware that this utility method ONLY works when called from an Activity! The above method calls getCurrentFocus of the target Activity to fetch the proper window token.

But suppose you want to hide the keyboard from an EditText hosted in a DialogFragment? You can't use the method above for that:

hideKeyboard(getActivity()); //won't work

This won't work because you'll be passing a reference to the Fragment's host Activity, which will have no focused control while the Fragment is shown! Wow! So, for hiding the keyboard from fragments, I resort to the lower-level, more common, and uglier:

public static void hideKeyboardFrom(Context context, View view) {
    InputMethodManager imm = (InputMethodManager) context.getSystemService(Activity.INPUT_METHOD_SERVICE);
    imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
}

Below is some additional information gleaned from more time wasted chasing this solution:

About windowSoftInputMode

There's yet another point of contention to be aware of. By default, Android will automatically assign initial focus to the first EditText or focusable control in your Activity. It naturally follows that the InputMethod (typically the soft keyboard) will respond to the focus event by showing itself. The windowSoftInputMode attribute in AndroidManifest.xml, when set to stateAlwaysHidden, instructs the keyboard to ignore this automatically-assigned initial focus.

<activity
    android:name=".MyActivity"
    android:windowSoftInputMode="stateAlwaysHidden"/>

Almost unbelievably, it appears to do nothing to prevent the keyboard from opening when you touch the control (unless focusable="false" and/or focusableInTouchMode="false" are assigned to the control). Apparently, the windowSoftInputMode setting applies only to automatic focus events, not to focus events triggered by touch events.

Therefore, stateAlwaysHidden is VERY poorly named indeed. It should perhaps be called ignoreInitialFocus instead.

Hope this helps.

UPDATE: More ways to get a window token

If there is no focused view (e.g. can happen if you just changed fragments), there are other views that will supply a useful window token.

These are alternatives for the above code if (view == null) view = new View(activity); These don't refer explicitly to your activity.

Inside a fragment class:

view = getView().getRootView().getWindowToken();

Given a fragment fragment as a parameter:

view = fragment.getView().getRootView().getWindowToken();

Starting from your content body:

view = findViewById(android.R.id.content).getRootView().getWindowToken();

UPDATE 2: Clear focus to avoid showing keyboard again if you open the app from the background

Add this line to the end of the method:

view.clearFocus();

sometimes all you want is the enter button to fold the keyboard give the EditText box you have the attribute

 android:imeOptions="actionDone" 

this will change the Enter button to a Done button that will close the keyboard.

Call this method to hide the soft keyboard

public void hideKeyBoard() {
    View view1 = this.getCurrentFocus();
    if(view!= null){
        InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.hideSoftInputFromWindow(view1.getWindowToken(), 0);
    }
}

I have written small extension for Kotlin if anyone interested, didn't test it much tho:

fun Fragment.hideKeyboard(context: Context = App.instance) {
    val windowToken = view?.rootView?.windowToken
    windowToken?.let {
        val imm = context.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
        imm.hideSoftInputFromWindow(windowToken, 0)
    }
}

App.instance is static "this" Application object stored in Application

Update: In some cases windowToken is null. I have added additional way of closing keyboard using reflection to detect if keyboard is closed

/**
 * If no window token is found, keyboard is checked using reflection to know if keyboard visibility toggle is needed
 *
 * @param useReflection - whether to use reflection in case of no window token or not
 */
fun Fragment.hideKeyboard(context: Context = MainApp.instance, useReflection: Boolean = true) {
    val windowToken = view?.rootView?.windowToken
    val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    windowToken?.let {
        imm.hideSoftInputFromWindow(windowToken, 0)
    } ?: run {
        if (useReflection) {
            try {
                if (getKeyboardHeight(imm) > 0) {
                    imm.toggleSoftInput(0, InputMethodManager.HIDE_NOT_ALWAYS)
                }
            } catch (exception: Exception) {
                Timber.e(exception)
            }
        }
    }
}

fun getKeyboardHeight(imm: InputMethodManager): Int = InputMethodManager::class.java.getMethod("getInputMethodWindowVisibleHeight").invoke(imm) as Int

Wiki answer in Kotlin :

1 - Create a top-level function inside a file (for example a file that contains all your top-level functions) :

fun Activity.hideKeyboard(){
    val imm = this.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
    var view = currentFocus
    if (view == null) { view = View(this) }
    imm.hideSoftInputFromWindow(view.windowToken, 0)
}

2 - Then call it in any activity you needed it :

this.hideKeyboard()

public void hideKeyboard() 
{
    if(getCurrentFocus()!=null) 
    {
        InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);
        inputMethodManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), 0);
    }
}


public void showKeyboard(View mView) {
    InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);
    mView.requestFocus();
    inputMethodManager.showSoftInput(mView, 0);
}

Here are both hide & show methods.

Kotlin

fun hideKeyboard(activity: Activity) {
    val v = activity.currentFocus
    val imm = activity.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    assert(v != null)
    imm.hideSoftInputFromWindow(v!!.windowToken, InputMethodManager.HIDE_NOT_ALWAYS)
}

private fun showKeyboard(activity: Activity) {
    val v = activity.currentFocus
    val imm = activity.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    assert(v != null)
    imm.showSoftInput(v, InputMethodManager.SHOW_IMPLICIT)
}

Java

public static void hideKeyboard(Activity activity) {
    View v = activity.getCurrentFocus();
    InputMethodManager imm = (InputMethodManager) activity.getSystemService(Context.INPUT_METHOD_SERVICE);
    assert imm != null && v != null;
    imm.hideSoftInputFromWindow(v.getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
}

private static void showKeyboard(Activity activity) {
    View v = activity.getCurrentFocus();
    InputMethodManager imm = (InputMethodManager) activity.getSystemService(Context.INPUT_METHOD_SERVICE);
    assert imm != null && v != null;
    imm.showSoftInput(v, InputMethodManager.SHOW_IMPLICIT);
}

 fun hideKeyboard(appCompatActivity: AppCompatActivity) {
        val view = appCompatActivity.currentFocus
        val imm = appCompatActivity.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
        imm.hideSoftInputFromWindow(view.windowToken, 0)
    }

Try this in Kotlin

 private fun hideKeyboard(){
    val imm = activity!!.getSystemService(INPUT_METHOD_SERVICE) as InputMethodManager
    imm.hideSoftInputFromWindow(activity!!.currentFocus!!.windowToken, 0)
}

Try this in Java

 private void hideKeyboard(){
  InputMethodManager imm =(InputMethodManager)getSystemService(INPUT_METHOD_SERVICE);
  imm.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), 0);
}

For Xamarin.Android:

public void HideKeyboard()
{
    var imm = activity.GetSystemService(Context.InputMethodService).JavaCast<InputMethodManager>();
    var view = activity.CurrentFocus ?? new View(activity);
    imm.HideSoftInputFromWindow(view.WindowToken, HideSoftInputFlags.None);
}

Actually, always Android authority is giving new updates but they are not handling their old drawbacks which all Android developers face in their development this should be handled by Android authority by default, on changing focus from EditText should hide/show soft input keyboard option. But sorry about that, they are not managing. Ok, leave it.

Below are the solutions to show/hide/toggle a keyboard option in Activity or Fragment.

Show keyboard for the view:

/**
 * open soft keyboard.
 *
 * @param context
 * @param view
 */
public static void showKeyBoard(Context context, View view) {
    try {
        InputMethodManager keyboard = (InputMethodManager) context.getSystemService(Context.INPUT_METHOD_SERVICE);
        keyboard.showSoftInput(view, 0);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Show keyboard with Activity context:

/**
 * open soft keyboard.
 *
 * @param mActivity context
 */
public static void showKeyBoard(Activity mActivity) {
    try {
        View view = mActivity.getCurrentFocus();
        if (view != null) {
            InputMethodManager keyboard = (InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
            keyboard.showSoftInputFromInputMethod(view.getWindowToken(), InputMethodManager.SHOW_FORCED);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Show keyboard with Fragment context:

/**
 * open soft keyboard.
 *
 * @param mFragment context
 */
public static void showKeyBoard(Fragment mFragment) {
    try {
        if (mFragment == null || mFragment.getActivity() == null) {
            return;
        }
        View view = mFragment.getActivity().getCurrentFocus();
        if (view != null) {
            InputMethodManager keyboard = (InputMethodManager) mFragment.getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
            keyboard.showSoftInputFromInputMethod(view.getWindowToken(), InputMethodManager.SHOW_FORCED);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Hide keyboard for the view:

/**
 * close soft keyboard.
 *
 * @param context
 * @param view
 */
public static void hideKeyBoard(Context context, View view) {
    try {
        InputMethodManager keyboard = (InputMethodManager) context.getSystemService(Context.INPUT_METHOD_SERVICE);
        keyboard.hideSoftInputFromWindow(view.getWindowToken(), 0);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Hide keyboard with Activity context:

/**
 * close opened soft keyboard.
 *
 * @param mActivity context
 */
public static void hideSoftKeyboard(Activity mActivity) {
    try {
        View view = mActivity.getCurrentFocus();
        if (view != null) {
            InputMethodManager inputManager = (InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
            inputManager.hideSoftInputFromWindow(view.getWindowToken(), 0);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Hide keyboard with Fragment context:

/**
 * close opened soft keyboard.
 *
 * @param mFragment context
 */
public static void hideSoftKeyboard(Fragment mFragment) {
    try {
        if (mFragment == null || mFragment.getActivity() == null) {
            return;
        }
        View view = mFragment.getActivity().getCurrentFocus();
        if (view != null) {
            InputMethodManager inputManager = (InputMethodManager) mFragment.getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
            inputManager.hideSoftInputFromWindow(view.getWindowToken(), 0);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Toggle Keyboard:

/**
 * toggle soft keyboard.
 *
 * @param context
 */
public static void toggleSoftKeyboard(Context context) {
    try {
        InputMethodManager imm = (InputMethodManager) context.getSystemService(Activity.INPUT_METHOD_SERVICE);
        imm.toggleSoftInput(InputMethodManager.HIDE_IMPLICIT_ONLY, 0);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

When you want to hide keyboard manually on the action of button click:

/**
 * Hides the already popped up keyboard from the screen.
 *
 */
public void hideKeyboard() {
    try {
        // use application level context to avoid unnecessary leaks.
        InputMethodManager inputManager = (InputMethodManager) getApplicationContext().getSystemService(Context.INPUT_METHOD_SERVICE);
        assert inputManager != null;
        inputManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

When you want to hide keyboard where ever you click on screen except edittext Override this method in your activity:

@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
    View view = getCurrentFocus();
    if (view != null && (ev.getAction() == MotionEvent.ACTION_UP || ev.getAction() == MotionEvent.ACTION_MOVE) && view instanceof EditText && !view.getClass().getName().startsWith("android.webkit.")) {
        int scrcoords[] = new int[2];
        view.getLocationOnScreen(scrcoords);
        float x = ev.getRawX() + view.getLeft() - scrcoords[0];
        float y = ev.getRawY() + view.getTop() - scrcoords[1];
        if (x < view.getLeft() || x > view.getRight() || y < view.getTop() || y > view.getBottom())
            ((InputMethodManager)this.getSystemService(Context.INPUT_METHOD_SERVICE)).hideSoftInputFromWindow((this.getWindow().getDecorView().getApplicationWindowToken()), 0);
    }
    return super.dispatchTouchEvent(ev);
}

To show keyboard on application start:

        getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN | WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE);
        view.requestFocus();
        new Handler().postDelayed(new Runnable() {
            public void run() {
                getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN);
            }
        }, 1000);

I'm using following Kotlin Activity extensions:

/**
 * Hides soft keyboard if is open.
 */
fun Activity.hideKeyboard() {
    currentFocus?.windowToken?.let {
        (getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager?)
                ?.hideSoftInputFromWindow(it, InputMethodManager.HIDE_NOT_ALWAYS)
    }
}

/**
 * Shows soft keyboard and request focus to given view.
 */
fun Activity.showKeyboard(view: View) {
    view.requestFocus()
    currentFocus?.windowToken?.let {
        (getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager?)
                ?.showSoftInput(view, InputMethodManager.SHOW_IMPLICIT)
    }
}

In Kotlin

fun hideKeyboard(activity: BaseActivity) {
        val view = activity.currentFocus?: View(activity)
        val imm = activity.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
        imm.hideSoftInputFromWindow(view.windowToken, 0)
    }

you can create Extension function for any View

fun View.hideKeyboard() = this.let {
    val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    imm.hideSoftInputFromWindow(windowToken, 0)
}

Example use with Activity

window.decorView.hideKeyboard();

Example use with View

etUsername.hideKeyboard();

Happy Coding...

Very simple way

I do this in all my projects, and work like a dream. In your declarations layout.xml just add this single line:

android:focusableInTouchMode="true"

Full code example:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:focusableInTouchMode="true">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <ListView
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

    </ListView>

</android.support.constraint.ConstraintLayout>

Please try this below code in onCreate()

EditText edtView=(EditText)findViewById(R.id.editTextConvertValue);
edtView.setInputType(0);

Some kotlin code:

Hide keyboard from Activity:

(currentFocus ?: View(this))
            .apply { (getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager)
                        .hideSoftInputFromWindow(windowToken, 0) }

If your application is targeting API Level 21 or more than there is a default method to use:

editTextObj.setShowSoftInputOnFocus(false);

Make sure you have set below code in EditText XML tag.

<EditText  
    ....
    android:enabled="true"
    android:focusable="true" />

In Android to hide the Vkeyboard by InputMethodManage you can cal hideSoftInputFromWindow by passing in the token of the window containing your focused view.

View view = this.getCurrentFocus();
if (view != null) {  
InputMethodManager im = 
(InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
im.hideSoftInputFromWindow(view.getWindowToken(), 0);
}

By Calling editText.clearFocus() and then InputMethodManager.HIDE_IMPLICIT_ONLY even works

I have spent more than two days working through all of the solutions posted in the thread and have found them lacking in one way or another. My exact requirement is to have a button that will with 100% reliability show or hide the on screen keyboard. When the keyboard is in its hidden state is should not re-appear, no matter what input fields the user clicks on. When it is in its visible state the keyboard should not disappear no matter what buttons the user clicks. This needs to work on Android 2.2+ all the way up to the latest devices.

You can see a working implementation of this in my app clean RPN.

After testing many of the suggested answers on a number of different phones (including froyo and gingerbread devices) it became apparent that android apps can reliably:

1. Temporarily hide the keyboard. It will re-appear again when a user focuses a new text field.
2. Show the keyboard when an activity starts and set a flag on the activity indicating that they keyboard should always be visible. This flag can only be set when an activity is initialising.
3. Mark an activity to never show or allow the use of the keyboard. This flag can only be set when an activity is initialising.

For me, temporarily hiding the keyboard is not enough. On some devices it will re-appear as soon as a new text field is focused. As my app uses multiple text fields on one page, focusing a new text field will cause the hidden keyboard to pop back up again.

Unfortunately item 2 and 3 on the list only work reliability when an activity is being started. Once the activity has become visible you cannot permanently hide or show the keyboard. The trick is to actually restart your activity when the user presses the keyboard toggle button. In my app when the user presses on the toggle keyboard button, the following code runs:

private void toggleKeyboard(){

    if(keypadPager.getVisibility() == View.VISIBLE){
        Intent i = new Intent(this, MainActivity.class);
        i.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
        Bundle state = new Bundle();
        onSaveInstanceState(state);
        state.putBoolean(SHOW_KEYBOARD, true);
        i.putExtras(state);

        startActivity(i);
    }
    else{
        Intent i = new Intent(this, MainActivity.class);
        i.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
        Bundle state = new Bundle();
        onSaveInstanceState(state);
        state.putBoolean(SHOW_KEYBOARD, false);
        i.putExtras(state);

        startActivity(i);
    }
}

This causes the current activity to have its state saved into a Bundle, and then the activity is started, passing through an boolean which indicates if the keyboard should be shown or hidden.

Inside the onCreate method the following code is run:

if(bundle.getBoolean(SHOW_KEYBOARD)){
    ((InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE)).showSoftInput(newEquationText,0);
    getWindow().setSoftInputMode(LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE);
}
else{
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM,
            WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM);
}

If the soft keyboard should be shown, then the InputMethodManager is told to show the keyboard and the window is instructed to make the soft input always visible. If the soft keyboard should be hidden then the WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM is set.

This approach works reliably on all devices I have tested on - from a 4 year old HTC phone running android 2.2 up to a nexus 7 running 4.2.2. The only disadvantage with this approach is you need to be careful with handling the back button. As my app essentially only has one screen (its a calculator) I can override onBackPressed() and return to the devices home screen.