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我的recyclerview位於左側抽屜碎片中。選擇一個項目後，當我向下滾動其他項目時也被誤選。我一次只需要選擇一個項目。我recyclerview適配器是這裏在Android中向下滾動時，會選擇recyclerview中的多個項目
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.List;
import static android.content.ContentValues.TAG;
public class NavigationDrawerAdapter extends RecyclerView.Adapter<NavigationDrawerAdapter.ViewHolder> {
private List<NavigationItem> mData;
private NavigationDrawerCallbacks mNavigationDrawerCallbacks;
private View mSelectedView;
private int mSelectedPosition;
public NavigationDrawerAdapter(List<NavigationItem> data) {
mData = data;
}
public NavigationDrawerCallbacks getNavigationDrawerCallbacks() {
return mNavigationDrawerCallbacks;
}
public void setNavigationDrawerCallbacks(NavigationDrawerCallbacks navigationDrawerCallbacks) {
mNavigationDrawerCallbacks = navigationDrawerCallbacks;
}
@Override
public NavigationDrawerAdapter.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.drawer_row, viewGroup, false);
final ViewHolder viewHolder = new ViewHolder(v);
viewHolder.itemView.setClickable(true);
viewHolder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mSelectedView != null) {
mSelectedView.setSelected(false);
}
mSelectedPosition = viewHolder.getAdapterPosition();
v.setSelected(true);
mSelectedView = v;
if (mNavigationDrawerCallbacks != null)
mNavigationDrawerCallbacks.onNavigationDrawerItemSelected(viewHolder.getAdapterPosition());
}
}
);
viewHolder.itemView.setBackgroundResource(R.drawable.row_selector);
return viewHolder;
}
@Override
public void onBindViewHolder(NavigationDrawerAdapter.ViewHolder viewHolder, int i) {
viewHolder.textView.setText(mData.get(i).getText());
viewHolder.textView.setCompoundDrawablesWithIntrinsicBounds(mData.get(i).getDrawable(), null, null, null);
if (mSelectedPosition == i) {
if (mSelectedView != null) {
mSelectedView.setSelected(false);
}
mSelectedPosition = i;
mSelectedView = viewHolder.itemView;
mSelectedView.setSelected(true);
}
}
public void selectPosition(int position) {
mSelectedPosition = position;
notifyItemChanged(position);
}
@Override
public int getItemCount() {
return mData != null ? mData.size() : 0;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView textView;
public ViewHolder(View itemView) {
super(itemView);
textView = (TextView) itemView.findViewById(R.id.item_name);
}
}
}
這裏是片段
import android.app.Activity;
import android.app.Fragment;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import java.util.ArrayList;
import java.util.List;
import static android.content.ContentValues.TAG;
import static android.content.Context.MODE_PRIVATE;
/**
* Fragment used for managing interactions for and presentation of a navigation drawer.
* See the <a href="https://developer.android.com/design/patterns/navigation-drawer.html#Interaction">
* design guidelines</a> for a complete explanation of the behaviors implemented here.
*/
public class NavigationDrawerFragment extends Fragment implements NavigationDrawerCallbacks {
/**
* Remember the position of the selected item.
*/
private static final String STATE_SELECTED_POSITION = "selected_navigation_drawer_position";
/**
* Per the design guidelines, you should show the drawer on launch until the user manually
* expands it. This shared preference tracks this.
*/
private static final String PREF_USER_LEARNED_DRAWER = "navigation_drawer_learned";
/**
* A pointer to the current callbacks instance (the Activity).
*/
private NavigationDrawerCallbacks mCallbacks;
/**
* Helper component that ties the action bar to the navigation drawer.
*/
private ActionBarDrawerToggle mActionBarDrawerToggle;
private DrawerLayout mDrawerLayout;
private RecyclerView mDrawerList;
private View mFragmentContainerView;
private int mCurrentSelectedPosition = 0;
private boolean mFromSavedInstanceState;
private boolean mUserLearnedDrawer;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Read in the flag indicating whether or not the user has demonstrated awareness of the
// drawer. See PREF_USER_LEARNED_DRAWER for details.
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity());
mUserLearnedDrawer = sp.getBoolean(PREF_USER_LEARNED_DRAWER, false);
if (savedInstanceState != null) {
mCurrentSelectedPosition = savedInstanceState.getInt(STATE_SELECTED_POSITION);
mFromSavedInstanceState = true;
}
SharedPreferences prefs = this.getActivity().getSharedPreferences("sub", MODE_PRIVATE);
mCurrentSelectedPosition = prefs.getInt("c", 0);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);
mDrawerList = (RecyclerView) view.findViewById(R.id.drawerList);
LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());
layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
mDrawerList.setLayoutManager(layoutManager);
mDrawerList.setHasFixedSize(true);
SharedPreferences prefs = this.getActivity().getSharedPreferences("sem", MODE_PRIVATE);
int b = prefs.getInt("b", 0);
List<NavigationItem> navigationItems;
if(b==0) {
navigationItems = getMenu();
}
else{
navigationItems = getMenu1();
}
NavigationDrawerAdapter adapter = new NavigationDrawerAdapter(navigationItems);
adapter.setNavigationDrawerCallbacks(this);
mDrawerList.setAdapter(adapter);
selectItem(mCurrentSelectedPosition);
return view;
}
public boolean isDrawerOpen() {
return mDrawerLayout != null && mDrawerLayout.isDrawerOpen(mFragmentContainerView);
}
public ActionBarDrawerToggle getActionBarDrawerToggle() {
return mActionBarDrawerToggle;
}
public DrawerLayout getDrawerLayout() {
return mDrawerLayout;
}
@Override
public void onNavigationDrawerItemSelected(int position) {
selectItem(position);
}
public List<NavigationItem> getMenu() {
List<NavigationItem> items = new ArrayList<NavigationItem>();
items.add(new NavigationItem("Linear Algebra & Complex Analysis", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Mechanics of Solids", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Fluid Mechanics I", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Engineering Geology", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Surveying", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Business Economics", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Life Skills", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Civil Engineering Drafting Lab", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Surveying Lab", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("About", getResources().getDrawable(R.drawable.ic_action_name)));
return items;
}
public List<NavigationItem> getMenu1() {
List<NavigationItem> items = new ArrayList<NavigationItem>();
items.add(new NavigationItem("Probability Distributions, Transforms and Numerical Methods", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Structural Analysis I", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Construction Technology", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Fluid Mechanics II", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Geotechnical Engineering I", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Life Skills", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Business Economics", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Materials Testing Lab I", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("Fluid Mechanics Lab", getResources().getDrawable(R.drawable.ic_menu_check2)));
items.add(new NavigationItem("About", getResources().getDrawable(R.drawable.ic_action_name)));
return items;
}
/**
* Users of this fragment must call this method to set up the navigation drawer interactions.
*
* @param fragmentId The android:id of this fragment in its activity's layout.
* @param drawerLayout The DrawerLayout containing this fragment's UI.
* @param toolbar The Toolbar of the activity.
*/
public void setup(int fragmentId, DrawerLayout drawerLayout, Toolbar toolbar) {
mFragmentContainerView = getActivity().findViewById(fragmentId);
mDrawerLayout = drawerLayout;
mDrawerLayout.setStatusBarBackgroundColor(getResources().getColor(R.color.myPrimaryDarkColor));
mActionBarDrawerToggle = new ActionBarDrawerToggle(getActivity(), mDrawerLayout, toolbar, R.string.drawer_open, R.string.drawer_close) {
@Override
public void onDrawerClosed(View drawerView) {
super.onDrawerClosed(drawerView);
if (!isAdded()) return;
getActivity().invalidateOptionsMenu(); // calls onPrepareOptionsMenu()
}
@Override
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
if (!isAdded()) return;
if (!mUserLearnedDrawer) {
mUserLearnedDrawer = true;
SharedPreferences sp = PreferenceManager
.getDefaultSharedPreferences(getActivity());
sp.edit().putBoolean(PREF_USER_LEARNED_DRAWER, true).apply();
}
getActivity().invalidateOptionsMenu(); // calls onPrepareOptionsMenu()
}
};
// If the user hasn't 'learned' about the drawer, open it to introduce them to the drawer,
// per the navigation drawer design guidelines.
if (!mUserLearnedDrawer && !mFromSavedInstanceState) {
//mDrawerLayout.openDrawer(mFragmentContainerView);
}
// Defer code dependent on restoration of previous instance state.
mDrawerLayout.post(new Runnable() {
@Override
public void run() {
mActionBarDrawerToggle.syncState();
}
});
mDrawerLayout.setDrawerListener(mActionBarDrawerToggle);
}
private void selectItem(int position) {
//Toast.makeText(this.getActivity(), "Menu " + String.valueOf(position), Toast.LENGTH_SHORT).show();
mCurrentSelectedPosition = position;
if (mDrawerLayout != null) {
mDrawerLayout.closeDrawer(mFragmentContainerView);
}
if (mCallbacks != null) {
mCallbacks.onNavigationDrawerItemSelected(position);
}
((NavigationDrawerAdapter) mDrawerList.getAdapter()).selectPosition(position);
}
public void openDrawer() {
mDrawerLayout.openDrawer(mFragmentContainerView);
}
public void closeDrawer() {
mDrawerLayout.closeDrawer(mFragmentContainerView);
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mCallbacks = (NavigationDrawerCallbacks) activity;
} catch (ClassCastException e) {
throw new ClassCastException("Activity must implement NavigationDrawerCallbacks.");
}
}
@Override
public void onDetach() {
super.onDetach();
mCallbacks = null;
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(STATE_SELECTED_POSITION, mCurrentSelectedPosition);
}
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Forward the new configuration the drawer toggle component.
mActionBarDrawerToggle.onConfigurationChanged(newConfig);
}
public void zxc(int a){
Log.d(TAG, "jlk "+mCurrentSelectedPosition);
List<NavigationItem> navigationItems;
if(a==0) {
navigationItems = getMenu();
}
else{
navigationItems = getMenu1();
}
NavigationDrawerAdapter adapter = new NavigationDrawerAdapter(navigationItems);
adapter.setNavigationDrawerCallbacks(this);
mDrawerList.setAdapter(adapter);
SharedPreferences.Editor editor = this.getActivity().getSharedPreferences("sub",MODE_PRIVATE).edit();
editor.putInt("c", 0);
editor.commit();
mCurrentSelectedPosition=0;
selectItem(mCurrentSelectedPosition);
}
}
能否請你給我的示例代碼相同 –