Question

我有一个导航抽屉实现，但问题是当按下后退按钮时，绘图中的已检查项目与当前片段（仅通过导航抽屉实际添加的最后一个片段）不对应

这里有一个解决方案：Updating the Navigation Drawer (with DrawerLayout) when back button is pressed

解决方案陈述如下：

getSupportFragmentManager().addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener() {
            @Override
            public void onBackStackChanged() {
                FragmentManager fm = getSupportFragmentManager();
                String stackName = null;
                for(int entry = 0; entry < fm.getBackStackEntryCount(); entry++){
                    stackName = fm.getBackStackEntryAt(entry).getName();
                    Log.i("BC", "stackEntry" + entry);
                }
                if (stackName == "Fragment1"){
                    mDrawerList.setItemChecked(0, true);
                } else if (stackName == "Fragment2") {
                    mDrawerList.setItemChecked(1, true);
                }

            });

问题是有条件的。当您拥有大量物品时，必须手动更改要检查的导航项目的索引是一件痛苦的事情

我想要做的是监听Backstack中的更改，如果检测到，则获取当前片段的id（如布局文件中所定义）并将其传递给navigationView.setCheckedItem()以自动检查相应的导航项目。像这样：

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

navigationView.setCheckedItem(R.id.nav_new);

在我的主要活动课程中，如何以R.id.xxx的形式获取当前片段的ID，以便将其传递给setCheckedItem？

Answer 1

你可以这样做

添加片段时执行此操作

RewriteEngine On
RewriteRule ^(home|empresa|instalaciones|acceso_clientes|nuevo_cliente|enviar_cliente|presupuestos|enviar_presupuesto|subir_archivo|enviar_archivo|suscribete|enviar_suscripcion|trabajos|hp-indigo-digital|packaging_plus|equipo_humano|oferta|enviar_oferta|contacto|privacidad)$ $1.php [L]

RewriteRule ^trabajos/([0-9]+) trabajos.php?id=$1 [L]
RewriteRule ^seccion_empresa/(.*) seccion_empresa.php?seccion=$1 [L]

然后

FragmentTransaction.addToBackStack(""+R.id.nav_new); // Use the id of navigation item which was clicked.

注意：当getSupportFragmentManager().addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener() { @Override public void onBackStackChanged() { FragmentManager fm = getSupportFragmentManager(); String stackName = null; for(int entry = 0; entry < fm.getBackStackEntryCount(); entry++){ stackName = fm.getBackStackEntryAt(entry).getName(); Log.i("BC", "stackEntry" + entry); } int navItemId = -1; try{ navItemId = Integer.parseInt(stackName); } catch(NumberFormatException nfe) { } if(navItemId > 0){ navigationView = (NavigationView) findViewById(R.id.nav_view); navigationView.setCheckedItem(navItemId); } else Log.e("", "Couldn't find the id"); });

上使用addToBackStack时，getName()中的任何内容都会返回给您

Answer 2

you can handle it manually.
Make a function in base class to highlight desired item like
mDrawerList.setItemChecked(INDEX NUMBER, true);

Trick is make a model class for side menu items in which INDEX NUMBER is saved.
When you replace new fragment call that function and store currentFragment a well.
and when you press back button ovverides

 public boolean onKeyDown(int keyCode, KeyEvent event) {}
and call below function

public void popAFragment(){
 FragmentManager fragmentManager = getSupportFragmentManager();
        if(fragmentManager != null){
            int c = fragmentManager.getBackStackEntryCount();
            if(c>0){
                currentFragment = (BaseFragment) fragmentManager.getFragments().get(c-1);
                fragmentManager.popBackStack();
                setPosition(currentFragment.INDEX_NUMBER);
            }
            else {
finish();
}
}

Android获取当前片段的ID

2 个答案: