Java 导航抽屉应用程序在单击时不会更改片段
早上好,我是一名新手程序员,我使用导航抽屉开始Android Studio活动。编译时一切都正常,但当我使用应用程序并单击不同的选项时,什么都没有发生(我的意思是布局没有改变并保持在activity_main.xml上)。我想问其他问题,但(我想)没有人有我的问题 主要活动:Java 导航抽屉应用程序在单击时不会更改片段,java,android,android-studio,android-fragments,navigation-drawer,Java,Android,Android Studio,Android Fragments,Navigation Drawer,早上好,我是一名新手程序员,我使用导航抽屉开始Android Studio活动。编译时一切都正常,但当我使用应用程序并单击不同的选项时,什么都没有发生(我的意思是布局没有改变并保持在activity_main.xml上)。我想问其他问题,但(我想)没有人有我的问题 主要活动: public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelected
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
private DrawerLayout drawer;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Ma giusto a provare", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
drawer = findViewById(R.id.drawer_layout);
NavigationView navigationView = findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.addDrawerListener(toggle);
toggle.syncState();
}
@Override
public void onBackPressed() {
DrawerLayout drawer = findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
switch(item.getItemId()) {
case R.id.nav_home:
ft.replace(R.id.fragment_container
, new CulturaClass()).commit();
break;
case R.id.nav_gallery:
ft.replace(R.id.fragment_container
, new CulturaClass()).commit();
break;
}
drawer.closeDrawer(GravityCompat.START);
return true;
}
}
main.xml
content_main.xml
活动\u main\u drawer.xml
fragment_cultura.xml
CulturaClass.java
公共类CultureClass扩展了片段{
@可空
@凌驾
创建视图时的公共视图(LayoutFlater充气机、@Nullable ViewGroup容器、@Nullable Bundle savedInstanceState){
返回充气机。充气(右布局。碎片培养物,容器,假);
}
activity_main.xml
因为您正在用相同的类替换片段:
因为您正在用相同的类替换片段:
你们可以用普通的函数或方法简单易行地完成这件事,而且你们永远不会出错 您有两种选择,一种是使用JAVA,另一种是KOTLIN 我在下面写的第一种方法是检查:
private Fragment fragment = null;
//create function for replace fragment
private void setFragment(Fragment fragmentName, String title) {
fragment = fragmentName;
if (fragment != null) {
// Insert the fragment by replacing any existing fragment
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction().replace(R.id.framelayout, fragment, fragment.getTag()).commit();
}
setTitle("Dashboard");
// Close the navigation drawer
drawerLayout.closeDrawers();
}
private var fragment: Fragment? = null
//create function for replace fragment
fun openFragment(fragmentClass: Fragment, titleName: String) {
//pass the current fragment class name which you replace
fragment = fragmentClass
//check first fragment is null or not
if (fragment != null) {
val fragmentManager = supportFragmentManager
fragmentManager.beginTransaction()
.replace(R.id.framelayout, fragment!!, fragment!!.tag).commit()
}
title = titleName // replace the titlename
//check the drawerLayout close or not
if (drawerLayout.isDrawerOpen(GravityCompat.START)) {
drawerLayout.closeDrawer(GravityCompat.START)
}
}
private Fragment fragment = null;
//create function for replace fragment
private void setFragment(Fragment fragmentName, String title) {
fragment = fragmentName;
if (fragment != null) {
// Insert the fragment by replacing any existing fragment
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction().replace(R.id.framelayout, fragment, fragment.getTag()).commit();
}
setTitle("Dashboard");
// Close the navigation drawer
drawerLayout.closeDrawers();
}
private var fragment: Fragment? = null
//create function for replace fragment
fun openFragment(fragmentClass: Fragment, titleName: String) {
//pass the current fragment class name which you replace
fragment = fragmentClass
//check first fragment is null or not
if (fragment != null) {
val fragmentManager = supportFragmentManager
fragmentManager.beginTransaction()
.replace(R.id.framelayout, fragment!!, fragment!!.tag).commit()
}
title = titleName // replace the titlename
//check the drawerLayout close or not
if (drawerLayout.isDrawerOpen(GravityCompat.START)) {
drawerLayout.closeDrawer(GravityCompat.START)
}
}
你们可以用普通的函数或方法简单易行地完成这件事,而且你们永远不会出错 您有两种选择,一种是使用JAVA,另一种是KOTLIN 我在下面写的第一种方法是检查:
private Fragment fragment = null;
//create function for replace fragment
private void setFragment(Fragment fragmentName, String title) {
fragment = fragmentName;
if (fragment != null) {
// Insert the fragment by replacing any existing fragment
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction().replace(R.id.framelayout, fragment, fragment.getTag()).commit();
}
setTitle("Dashboard");
// Close the navigation drawer
drawerLayout.closeDrawers();
}
private var fragment: Fragment? = null
//create function for replace fragment
fun openFragment(fragmentClass: Fragment, titleName: String) {
//pass the current fragment class name which you replace
fragment = fragmentClass
//check first fragment is null or not
if (fragment != null) {
val fragmentManager = supportFragmentManager
fragmentManager.beginTransaction()
.replace(R.id.framelayout, fragment!!, fragment!!.tag).commit()
}
title = titleName // replace the titlename
//check the drawerLayout close or not
if (drawerLayout.isDrawerOpen(GravityCompat.START)) {
drawerLayout.closeDrawer(GravityCompat.START)
}
}
private Fragment fragment = null;
//create function for replace fragment
private void setFragment(Fragment fragmentName, String title) {
fragment = fragmentName;
if (fragment != null) {
// Insert the fragment by replacing any existing fragment
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction().replace(R.id.framelayout, fragment, fragment.getTag()).commit();
}
setTitle("Dashboard");
// Close the navigation drawer
drawerLayout.closeDrawers();
}
private var fragment: Fragment? = null
//create function for replace fragment
fun openFragment(fragmentClass: Fragment, titleName: String) {
//pass the current fragment class name which you replace
fragment = fragmentClass
//check first fragment is null or not
if (fragment != null) {
val fragmentManager = supportFragmentManager
fragmentManager.beginTransaction()
.replace(R.id.framelayout, fragment!!, fragment!!.tag).commit()
}
title = titleName // replace the titlename
//check the drawerLayout close or not
if (drawerLayout.isDrawerOpen(GravityCompat.START)) {
drawerLayout.closeDrawer(GravityCompat.START)
}
}
代替
R.id.fragment\u容器
在activity\u main.xml
中提供FrameLayout
的名称,并在替换片段时传递该名称,即
case R.id.nav_home:
ft.replace(R.id.<name_of_framelayout>, new CulturaClass()).commit();
break;
case R.id.nav_gallery:
ft.replace(R.id.<name_of_framelayout>, new CulturaClass()).commit();
break;
case R.id.nav_home:
ft.replace(R.id.,new CulturalClass()).commit();
打破
案例R.id.nav_画廊:
ft.replace(R.id.,new CulturalClass()).commit();
打破
这可能适用于您而不是
R.id.fragment\u容器
在activity\u main.xml
中为FrameLayout
提供名称,并在替换片段时传递该名称,即
case R.id.nav_home:
ft.replace(R.id.<name_of_framelayout>, new CulturaClass()).commit();
break;
case R.id.nav_gallery:
ft.replace(R.id.<name_of_framelayout>, new CulturaClass()).commit();
break;
case R.id.nav_home:
ft.replace(R.id.,new CulturalClass()).commit();
打破
案例R.id.nav_画廊:
ft.replace(R.id.,new CulturalClass()).commit();
打破
这可能对你有用你能分享一些代码吗?发布你导航抽屉项目点击的代码。当然,我以为我这样做了。很抱歉,我将修改
onNavigationItemSelected()中的问题
method您在两种情况下都替换了相同的片段。您可以共享一些代码吗?发布导航抽屉中项目单击的代码。当然,我以为我这样做了。很抱歉,我将修改onNavigationItemSelected()中的问题
method您在两种情况下都替换了相同的片段。非常感谢,但这不是问题,事实上从未更改过主页。我的意思是,在CulturalClass中,我加载了fragment\u cultura,它有一个按钮和一个文本视图,但我看不到它们。否,您再次加载了相同的类。我按照您的建议更改了代码,但页面上没有任何更改app@B我已添加CultureClass()代码。无论如何,没有任何更改:(然后切换到另一个类!!非常感谢,但这不是问题,事实上从未更改过主页。我的意思是,在CulturalClass中,我加载fragment_cultura,它有一个按钮和文本视图,但我看不到它们否,您再次加载同一个类。我按照您的建议更改了代码,但在app@Blogger我加了一句lass()代码。无论如何,没有任何更改:(然后更改为另一个类!!