我该怎么做才能打开另一个布局？

Question

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle presses on the action bar items
    switch (item.getItemId()) {
        case R.id.action_settings:

（我必须在这里写一下应用程序会打开另一项活动吗？）

Answer 1

switch (item.getItemId()){
   case R.id.action_settings:
       Intent i = new Intent(this, AnotherActivity.class);
       startActivity(i);
       break;
}

Answer 2

写下此内容以打开新活动 -

@Override
public boolean onOptionsItemSelected(MenuItem item) 
{
    // Handle presses on the action bar items
    switch (item.getItemId()) 
    {
        case R.id.action_settings:
Intent intent = new Intent(YourCurrentActivity.this, NextActivity.class);
startActivity(intent);