次のカスタムクラスを試してコピーして貼り付けてください Edittext
public class SegoeUiEditText extends AppCompatEditText {
private final Context context;
@Override
public boolean isSuggestionsEnabled() {
    return false;
}
public SegoeUiEditText(Context context) {
    super(context);
    this.context = context;
    init();
}
public SegoeUiEditText(Context context, AttributeSet attrs) {
    super(context, attrs);
    this.context = context;
    init();
}
public SegoeUiEditText(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    this.context = context;
    init();
}
private void setFonts(Context context) {
    this.setTypeface(Typeface.createFromAsset(context.getAssets(), "Fonts/Helvetica-Normal.ttf"));
}
private void init() {
        setTextIsSelectable(false);
        this.setCustomSelectionActionModeCallback(new ActionModeCallbackInterceptor());
        this.setLongClickable(false);
}
@Override
public int getSelectionStart() {
    for (StackTraceElement element : Thread.currentThread().getStackTrace()) {
        if (element.getMethodName().equals("canPaste")) {
            return -1;
        }
    }
    return super.getSelectionStart();
}
/**
 * Prevents the action bar (top horizontal bar with cut, copy, paste, etc.) from appearing
 * by intercepting the callback that would cause it to be created, and returning false.
 */
private class ActionModeCallbackInterceptor implements ActionMode.Callback, android.view.ActionMode.Callback {
    private final String TAG = SegoeUiEditText.class.getSimpleName();
    public boolean onCreateActionMode(ActionMode mode, Menu menu) { return false; }
    public boolean onPrepareActionMode(ActionMode mode, Menu menu) { return false; }
    public boolean onActionItemClicked(ActionMode mode, MenuItem item) { return false; }
    public void onDestroyActionMode(ActionMode mode) {}
    @Override
    public boolean onCreateActionMode(android.view.ActionMode mode, Menu menu) {
        return false;
    }
    @Override
    public boolean onPrepareActionMode(android.view.ActionMode mode, Menu menu) {
        menu.clear();
        return false;
    }
    @Override
    public boolean onActionItemClicked(android.view.ActionMode mode, MenuItem item) {
        return false;
    }
    @Override
    public void onDestroyActionMode(android.view.ActionMode mode) {
    }
}
}