Android – How to install an APK file on an Android phone

After tracking down this problem as well, I found this note in the Android documentation:

http://source.android.com/source/using-eclipse.html

*Note: Eclipse sometimes likes to add an "import android.R" statement at the top of your files that use resources, especially when you ask Eclipse to sort or otherwise manage imports. This will cause your make to break. Look out for these erroneous import statements and delete them.*

While going through the Android sample tutorials, I would often use the Ctrl + Shift + O command to "Organize Imports" and generate any missing import statements. Sometimes this would generate the incorrect import statement which would hide the R.java class that is automatically generated when you build.

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 the menu).

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

Kotlin Syntax

// Only runs if there is a view that is currently focused
this.currentFocus?.let { view ->
    val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager
    imm?.hideSoftInputFromWindow(view.windowToken, 0)
}