首先，对新手的问题表示歉意。
我正在尝试实现一个导航抽屉，它将在我的应用程序中使用。首先，我遵循了Android教程，创建了一个基本的导航，它用Fragments更改了a。
我可以将framelayout id和fragment传递给FragmentTransaction。它非常有效。
我决定用默认的android文件创建一个新的登录活动（在android Studio中：转到new-activity-login activity）。这就是让我困惑的地方。我的问题是：
-
我可以创建登录活动的一个片段吗？LoginActivity中的操作将在其中工作？看起来片段将根据传递的布局创建一个视图，但LoginActivity中使用的方法不起作用？
-
如果创建一个片段不适用于登录活动，那么在切换活动时，确保导航工作的最干净的方法是什么？导航抽屉仅在主活动中工作；切换到其他活动（通过Intent）会导致应用程序丢失导航抽屉操作。操作栏/导航抽屉的图像仍然存在。
以下是我在MainActivity中的一些代码。。。当Intent切换活动时，可能我遗漏了导致导航抽屉停止工作的东西？
（注意：LoginActivity扩展了LoginActivity类中的MainActivity）
提前感谢您的指导/建议！
public class MainActivity extends ActionBarActivity {
private NavigationDrawerFragment mNavigationDrawerFragment;
//USER DATA
public String mUserID;
public String mToken;
public String mProgramData;
//NAVIGATION DRAWER
private CharSequence mTitle;
private CharSequence mDrawerTitle;
private String[] mTitles;
private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private ActionBarDrawerToggle mActionBarDrawerToggle;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTitle = mDrawerTitle = getTitle();
// get list items for nav
mTitles = getResources().getStringArray(R.array.nav_menu);
//drawer widget
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
//listview of left drawer
mDrawerList = (ListView) findViewById(R.id.left_drawer);
// Set up the drawer.
mDrawerList.setAdapter(new ArrayAdapter<>(this,
R.layout.drawer_list_item, mTitles));
//set onclicklistener on the each list item of menu options
mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
// some styling...
mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
//enables action bar app behavior
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
// ties drawerlayout and actionbar for navigation drawers
mActionBarDrawerToggle = new ActionBarDrawerToggle(
this,
mDrawerLayout,
R.string.navigation_drawer_open,
R.string.navigation_drawer_close) {
// different titles for the drawer actions
public void onDrawerClosed(View drawerView) {
getSupportActionBar().setTitle(mTitle);
}
public void onDrawerOpened(View drawerView) {
getSupportActionBar().setTitle(mDrawerTitle);
}
};
// set drawer toggle as the drawer listener
mDrawerLayout.setDrawerListener(mActionBarDrawerToggle);
}
private class DrawerItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id){
selectItem(position);
}
}
@Override
protected void onPostCreate(Bundle savedInstanceState){
super.onPostCreate(savedInstanceState);
mActionBarDrawerToggle.syncState();
}
@Override
public void onConfigurationChanged(Configuration newConfig){
super.onConfigurationChanged(newConfig);
mActionBarDrawerToggle.onConfigurationChanged(newConfig);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (mActionBarDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
switch(id) {
case R.id.action_home:
Intent home = new Intent(this, MainActivity.class);
this.startActivity(home);
break;
case R.id.action_login:
Intent login = new Intent(this, LoginActivity.class);
this.startActivity(login);
break;
}
return super.onOptionsItemSelected(item);
}
编辑
感谢你到目前为止在指导我解决问题方面的帮助。不幸的是，我认为我问的问题不对，但也许查看安卓工作室的登录活动代码会有所帮助。
这是登录活动:的一部分
public class LoginActivity extends MainActivity implements LoaderCallbacks<Cursor> {
private UserLoginTask mAuthTask = null;
// UI references.
private AutoCompleteTextView mUserIDView;
private EditText mPasswordView;
private View mProgressView;
private View mLoginFormView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
// Set up the login form.
mUserIDView = (AutoCompleteTextView) findViewById(R.id.email);
populateAutoComplete();
mPasswordView = (EditText) findViewById(R.id.password);
mPasswordView.setOnEditorActionListener(new TextView.OnEditorActionListener() {
@Override
public boolean onEditorAction(TextView textView, int id, KeyEvent keyEvent) {
if (id == R.id.login || id == EditorInfo.IME_NULL) {
attemptLogin();
return true;
}
return false;
}
});
Button mEmailSignInButton = (Button) findViewById(R.id.email_sign_in_button);
mEmailSignInButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
attemptLogin();
}
});
mLoginFormView = findViewById(R.id.login_form);
mProgressView = findViewById(R.id.login_progress);
}
private void populateAutoComplete() {
getLoaderManager().initLoader(0, null, this);
}
/**
* Attempts to sign in or register the account specified by the login form.
* If there are form errors (invalid email, missing fields, etc.), the
* errors are presented and no actual login attempt is made.
*/
public void attemptLogin() {
if (mAuthTask != null) {
return;
}
// Reset errors.
mUserIDView.setError(null);
mPasswordView.setError(null);
// Store values at the time of the login attempt.
String email = mUserIDView.getText().toString();
String password = mPasswordView.getText().toString();
boolean cancel = false;
View focusView = null;
// Check for a valid password, if the user entered one.
if (TextUtils.isEmpty(password)) {
mPasswordView.setError(getString(R.string.error_invalid_password));
focusView = mPasswordView;
cancel = true;
}
// Check for a valid email address or ID.
if (TextUtils.isEmpty(email)) {
mUserIDView.setError(getString(R.string.error_field_required));
focusView = mUserIDView;
cancel = true;
} else if (!isEmailValid(email) && !isIDValid(email)) {
mUserIDView.setError(getString(R.string.error_invalid_email));
focusView = mUserIDView;
cancel = true;
}
if (cancel) {
// There was an error; don't attempt login and focus the first
// form field with an error.
focusView.requestFocus();
} else {
// Show a progress spinner, and kick off a background task to
// perform the user login attempt.
showProgress(true);
mAuthTask = new UserLoginTask(email, password);
mAuthTask.execute((Void) null);
}
}
private boolean isEmailValid(String email) {
//TODO: Replace this with your own logic
return email.contains("@");
}
private boolean isIDValid(String email) {
//TODO: Replace this with your own logic
return email.length() == 6;
}
[continued]...........
我将创建一个名为menu1_fragment:的LoginActivity的简单片段
public class menu1_Fragment extends android.support.v4.app.Fragment {
View rootview;
public View onCreateView(LayoutInflater inflater, ViewGroup view, Bundle savedInstanceState) {
rootview = (ViewGroup)inflater.inflate(R.layout.activity_login, null);
return rootview;
}
}
如果我是正确的（希望我错了！），则片段将替换为View（menu1_fragment）。视图不能有操作（如单击登录按钮发送httppost请求）。
此外，您能否解释一下MainActivity中的OptionsItemSelected会破坏导航绘图器的原因（抽屉变得不可点击。也无法向右滑动以将其向上拉）。Intent启动一个活动（LoginActivity），但只显示外观中的抽屉。
也可以隐藏ActionBar图标，您可以这样做：
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// toggle nav drawer on selecting action bar app icon/title
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
// Handle action bar actions click
switch (item.getItemId()) {
case R.id.action_settings:
return true;
default:
return super.onOptionsItemSelected(item);
}
}
对于replace主fragment，当您单击drawable menu list中的项目时，我看到您使用了selectItem(position)方法，但该方法从未在代码中声明。要做到这一点，你也可以做一些类似的事情：
private void selectItem(int position){
// update the main content by replacing fragments
Fragment fragment = null;
switch (position) {
case 1:
fragment = new TestFragment();
break;
case 2:
fragment = new TestFragment2();
break;
default:
break;
}
if (fragment != null) {
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
// update selected item and title, then close the drawer
setTitle(navMenuTitles[position]);
mDrawerList.setItemChecked(position, true);
mDrawerList.setSelection(position);
mDrawerLayout.closeDrawer(mDrawerList);
} else {
// error in creating fragment
Log.e("MainActivity", "Error in creating fragment");
}
}
我给你举了一个例子，其中多个活动被定义为片段，并使用MainActivity调用，希望你能在其中找到你的解决方案。
主活动.java
package com.example.fragmentdemo1;
import java.util.ArrayList;
import android.os.Bundle;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.ActionBarActivity;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class MainActivity extends ActionBarActivity implements
OnItemClickListener {
MainActivity activity;
private ListView lv;
private ArrayList<String> list = new ArrayList<String>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
activity = this;
lv = (ListView) findViewById(R.id.listView);
list.add("First");
list.add("Second");
list.add("Third");
list.add("Forth");
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(activity,
android.R.layout.simple_list_item_1, list);
lv.setAdapter(adapter);
lv.setOnItemClickListener(this);
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
switch (position) {
case 0:
Fragment1 f1 = new Fragment1();
FragmentTransaction transaction = getSupportFragmentManager()
.beginTransaction();
transaction.addToBackStack(null);
transaction.replace(R.id.container, f1).commit();
break;
case 1:
Fragment2 f2 = new Fragment2();
FragmentTransaction transaction2 = getSupportFragmentManager()
.beginTransaction();
transaction2.addToBackStack(null);
transaction2.replace(R.id.container, f2).commit();
break;
case 2:
Toast.makeText(activity, "" + position, 1000).show();
Fragment3 f3 = new Fragment3();
FragmentTransaction transaction3 = getSupportFragmentManager()
.beginTransaction();
transaction3.addToBackStack(null);
transaction3.replace(R.id.container, f3).commit();
break;
case 3:
Fragment4 f4 = new Fragment4();
FragmentTransaction transaction4 = getSupportFragmentManager()
.beginTransaction();
transaction4.addToBackStack(null);
transaction4.replace(R.id.container, f4).commit();
break;
default:
break;
}
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
switch (id) {
case android.R.id.home:
finish();
break;
default:
break;
}
return false;
}
}
片段1.java
package com.example.fragmentdemo1;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class Fragment1 extends android.support.v4.app.Fragment{
TextView tv;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup view,
Bundle savedInstanceState) {
tv =(TextView)view.findViewById(R.id.textView1);
view = (ViewGroup) inflater.inflate(R.layout.fragment1, null);
return view;
}
}
Fragment2.java
package com.example.fragmentdemo1;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class Fragment2 extends Fragment {
TextView tv;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup view,
Bundle savedInstanceState) {
tv =(TextView)view.findViewById(R.id.textView2);
view = (ViewGroup) inflater.inflate(R.layout.fragment2, null);
return view;
}
}
Fragment3.java
package com.example.fragmentdemo1;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class Fragment3 extends Fragment {
TextView tv;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup view,
Bundle savedInstanceState) {
tv =(TextView)view.findViewById(R.id.textView3);
view =(ViewGroup)inflater.inflate(R.layout.fragment3, null);
return view;
}
}
Fragment4.java
package com.example.fragmentdemo1;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class Fragment4 extends Fragment{
TextView tv;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup view,
Bundle savedInstanceState) {
tv =(TextView)view.findViewById(R.id.textView4);
view = (ViewGroup)inflater.inflate(R.layout.fragment4, null);
return view;
}
}
注意：如果您想使用从Fragment类到MainActivity的方法，那么您可以将其设为public static，并且您可以通过它的类名（如Fragment1.countData()）直接使用该方法。
此演示也适用于导航抽屉。