Question

原谅我的英语：（

我遇到“NavigationDrawer”的问题。我有没有特殊活动的碎片“Home”，“Import，Gallery和SlideShow”，所有活动都运行得很好。但是，如果我单击导入（HOME＆gt; IMPORT），活动IMPORT将打开，但如果我单击（IMPORT＆gt; GALLERY / SLIDESHOW / HOME），导入活动将保持打开状态。我必须按后退按钮才能进入HOME，点击其他活动

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);



    drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

    navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);
}

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) 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.home, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    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.
    //here is the main place where we need to work on.
int id=item.getItemId();
    switch (id){

        case R.id.nav_home:
            Intent h= new Intent(Home.this,Home.class);
            startActivity(h);
            break;
        case R.id.nav_import:
            Intent i= new Intent(Home.this,Import.class);
            startActivity(i);
            break;
        case R.id.nav_gallery:
            Intent g= new Intent(Home.this,Gallery.class);
            startActivity(g);
            break;

        case R.id.nav_slideshow:
            Intent s= new Intent(Home.this,Slideshow.class);
            startActivity(s);
            break;
        // oh nightmare
    }



    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

进口活动

public class Import extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener {

DrawerLayout drawer;
NavigationView navigationView;
Toolbar toolbar=null;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_import);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    Button Button9 = (Button) findViewById(R.id.Button9);
    Button Button11 = (Button) findViewById(R.id.Button11);

    //We dont need this.


    drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

    navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);

    Button9.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            Intent it = new Intent(Import.this, PHP5.class);
            startActivity(it);
        }
    });

    Button11.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            Intent it = new Intent(Import.this, PHP7.class);
            startActivity(it);
        }
    });


}

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) 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.home, 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.
    //here is the main place where we need to work on.
    int id=item.getItemId();
    switch (id){

        case R.id.nav_home:
            Intent h= new Intent(Import.this,Home.class);
            startActivity(h);
            break;
        case R.id.nav_import:
            Intent i= new Intent(Import.this,Import.class);
            startActivity(i);
            break;
        case R.id.nav_gallery:
            Intent g= new Intent(Import.this,Gallery.class);
            startActivity(g);
            break;
        case R.id.nav_slideshow:
            Intent s= new Intent(Import.this,Slideshow.class);
            startActivity(s);
            break;

        // after this lets start copying the above.
        // FOLLOW MEEEEE>>>
        //copy this now.
    }



    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

}

Answer 1

也许您忘记在finish()中致电IMPORT Activity了？如果您在Intent之后调用另一个Activity，则当前活动将关闭，您的Home Activity将再次显示。

Answer 2

您需要从堆栈中删除所有先前的活动，可以通过意图

中的标记来完成

         Intent it = new Intent(Import.this, OtherAct.class);
         it.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
         startActivity(it);

否则，密钥的组合可能适合您：

         it.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);

检查有关其工作原理的文档： https://developer.android.com/reference/android/content/Intent.html#FLAG_ACTIVITY_CLEAR_TOP https://developer.android.com/reference/android/content/Intent.html#FLAG_ACTIVITY_NEW_TASK https://developer.android.com/reference/android/content/Intent.html#FLAG_ACTIVITY_CLEAR_TASK

NavigationDrawer中的问题（交换活动）

2 个答案: