Question

概述 ::

我有一个导航抽屉
当位置为textView时，我在适配器中设置0颜色到red
在列表中选择textView设置为的不同元素 red和其他black
因此，任何时候只能在textview中设置一个red（已选中）适配器）black
另请注意我为textview设置红色的原因位置为o时的适配器，因为它是第一次加载时显示的第一个片段
当我选择其他适配器时，必须取消选择发生

我使用的代码是 ::

private class SlideMenuClickListener implements
ListView.OnItemClickListener {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position,
            long id) {
        // display view for selected nav drawer item
        displayView(position);
        setNavDrawerItemNormal();
        title=(TextView) view.findViewById(R.id.title);
        title.setTextColor(getApplicationContext().getResources().getColor(R.color.red));

    }
}


public void setNavDrawerItemNormal()
{
    for (int i=0; i< mDrawerList.getChildCount(); i++)
    {
        View v = mDrawerList.getChildAt(i);
        TextView txtview = ((TextView) v.findViewById(R.id.title));
        txtview.setTextColor(getApplicationContext().getResources().getColor(R.color.black));
    }
}

MainActivity.java

public class MainActivity extends Activity {
    private DrawerLayout mDrawerLayout;
    private GridView mDrawerList;
    private ActionBarDrawerToggle mDrawerToggle;

    // nav drawer title
    private CharSequence mDrawerTitle;

    // used to store app title
    private CharSequence mTitle;

    // slide menu items
    private String[] navMenuTitles;
    private TypedArray navMenuIcons;

    private ArrayList<NavDrawerItem> navDrawerItems;
    private NavDrawerListAdapter adapter;

    private TextView title;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mTitle = mDrawerTitle = getTitle();

        // load slide menu items
        navMenuTitles = getResources().getStringArray(R.array.nav_drawer_items);

        // nav drawer icons from resources
        navMenuIcons = getResources()
                .obtainTypedArray(R.array.nav_drawer_icons);

        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerList = (GridView) findViewById(R.id.list_slidermenu);


        navDrawerItems = new ArrayList<NavDrawerItem>();

        // adding nav drawer items to array
        // Home
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[0], navMenuIcons.getResourceId(0, -1)));
        // Find People
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[1], navMenuIcons.getResourceId(1, -1)));
        // Photos
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[2], navMenuIcons.getResourceId(2, -1)));
        // Communities, Will add a counter here
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[3], navMenuIcons.getResourceId(3, -1), true, "22"));
        // Pages
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[4], navMenuIcons.getResourceId(4, -1)));
        // What's hot, We  will add a counter here
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[5], navMenuIcons.getResourceId(5, -1), true, "50+"));


        // Recycle the typed array
        navMenuIcons.recycle();

        mDrawerList.setOnItemClickListener(new SlideMenuClickListener());

        // setting the nav drawer list adapter
        adapter = new NavDrawerListAdapter(getApplicationContext(),
                navDrawerItems);
        mDrawerList.setAdapter(adapter);

        // enabling action bar app icon and behaving it as toggle button
        getActionBar().setDisplayHomeAsUpEnabled(true);
        //getActionBar().setHomeButtonEnabled(true);

        mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
                R.drawable.ic_drawer, //nav menu toggle icon
                R.string.app_name, // nav drawer open - description for accessibility
                R.string.app_name // nav drawer close - description for accessibility
                ) {
            public void onDrawerClosed(View view) {
                getActionBar().setTitle(mTitle);
                // calling onPrepareOptionsMenu() to show action bar icons
                invalidateOptionsMenu();
            }

            public void onDrawerOpened(View drawerView) {
                getActionBar().setTitle(mDrawerTitle);
                // calling onPrepareOptionsMenu() to hide action bar icons
                invalidateOptionsMenu();
            }
        };
        mDrawerLayout.setDrawerListener(mDrawerToggle);

        if (savedInstanceState == null) {
            // on first time display view for first nav item
            displayView(0);
        }
    }

    /**
     * Slide menu item click listener
     * */
    private class SlideMenuClickListener implements
    ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position,
                long id) {
            // display view for selected nav drawer item
            displayView(position);
            setNavDrawerItemNormal();
            title=(TextView) view.findViewById(R.id.title);
            title.setTextColor(getApplicationContext().getResources().getColor(R.color.red));

        }
    }


    public void setNavDrawerItemNormal()
    {
        for (int i=0; i< mDrawerList.getChildCount(); i++)
        {
            View v = mDrawerList.getChildAt(i);
            TextView txtview = ((TextView) v.findViewById(R.id.title));
            txtview.setTextColor(getApplicationContext().getResources().getColor(R.color.black));
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @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);
        }
    }

    /* *
     * Called when invalidateOptionsMenu() is triggered
     */
    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        // if nav drawer is opened, hide the action items
        boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
        menu.findItem(R.id.action_settings).setVisible(!drawerOpen);
        return super.onPrepareOptionsMenu(menu);
    }

    /**
     * Diplaying fragment view for selected nav drawer list item
     * */
    private void displayView(int position) {
        // update the main content by replacing fragments
        Fragment fragment = null;
        switch (position) {
        case 0:
            fragment = new HomeFragment();
            break;
        case 1:
            fragment = new FragmentOne();
            break;
        case 2:
            fragment = new FragmentTwo();
            break;
        case 3:
            fragment = new FragmentThree();
            break;
        case 4:
            fragment = new FragmentFour();
            break;
        case 5:
            fragment = new FragmentFive();
            break;

        default:
            break;
        }

        if (fragment != null) {
            FragmentManager fragmentManager = getFragmentManager();
            fragmentManager.beginTransaction()
            .replace(R.id.content_frame, fragment).commit();

            // update selected item and title, then close the drawer
            mDrawerList.setItemChecked(position, true);
            mDrawerList.setSelection(position);
            setTitle(navMenuTitles[position]);
            mDrawerLayout.closeDrawer(mDrawerList);
        } else {
            // error in creating fragment
            Log.e("MainActivity", "Error in creating fragment");
        }
    }




    @Override
    public void setTitle(CharSequence title) {
        mTitle = title;
        getActionBar().setTitle(mTitle);
    }

    /**
     * When using the ActionBarDrawerToggle, you must call it during
     * onPostCreate() and onConfigurationChanged()...
     */

    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        // Sync the toggle state after onRestoreInstanceState has occurred.
        mDrawerToggle.syncState();
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        // Pass any configuration change to the drawer toggls
        mDrawerToggle.onConfigurationChanged(newConfig);
    }

}

NavDrawerListAdapter.java

public class NavDrawerListAdapter extends BaseAdapter {

    private Context context;
    private ArrayList<NavDrawerItem> navDrawerItems;

    public NavDrawerListAdapter(Context context, ArrayList<NavDrawerItem> navDrawerItems){
        this.context = context;
        this.navDrawerItems = navDrawerItems;
    }

    @Override
    public int getCount() {
        return navDrawerItems.size();
    }

    @Override
    public Object getItem(int position) {       
        return navDrawerItems.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        if (convertView == null) {
            LayoutInflater mInflater = (LayoutInflater)
                    context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
            convertView = mInflater.inflate(R.layout.drawer_list_item, null);
        }

        ImageView imgIcon = (ImageView) convertView.findViewById(R.id.icon);
        TextView txtTitle = (TextView) convertView.findViewById(R.id.title);

        if (position == 0) 
        { 
            txtTitle.setTextColor(context.getResources().getColor(R.color.red));
        }

        imgIcon.setImageResource(navDrawerItems.get(position).getIcon());        
        txtTitle.setText(navDrawerItems.get(position).getTitle());


        return convertView;
    }

}

NOTE ::我可以通过应用程序变量实现我的目标，但我试图在没有它的情况下，以编程方式实现

Answer 1

您不需要在适配器/活动中包含任何其他变量的主要想法，因为Android组件已经有一个用于单选的列表。以下解决方案适用于您的情况：

假设您的布局（ activity_main.xml ）：

<android.support.v4.widget.DrawerLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <!-- The main content view -->
    <FrameLayout
        android:id="@+id/content_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
    <!-- The navigation drawer -->
    <GridView android:id="@+id/list_slidermenu"
              android:layout_width="240dp"
              android:layout_height="match_parent"
              android:layout_gravity="start"
              android:choiceMode="singleChoice"
              android:divider="@android:color/transparent"
              android:dividerHeight="0dp"
              android:background="#111"/>
</android.support.v4.widget.DrawerLayout>

请注意android:choiceMode="singleChoice" - 该属性会让列表自行跟踪所选项目。

从活动中删除所有颜色设置代码。相反，使用setChecked（）让列表知道选择了哪个项目：

public class MainActivity extends ActionBarActivity {

    private static final String TAG = "MainActivity";
    private DrawerLayout mDrawerLayout;
    private GridView mDrawerList;
    private ActionBarDrawerToggle mDrawerToggle;

    // nav drawer title
    private CharSequence mDrawerTitle;

    // used to store app title
    private CharSequence mTitle;

    // slide menu items
    private String[] navMenuTitles;
    private TypedArray navMenuIcons;

    private ArrayList<NavDrawerItem> navDrawerItems;
    private NavDrawerListAdapter adapter;

    private TextView title;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mTitle = mDrawerTitle = getTitle();

        // load slide menu items
        navMenuTitles = getResources().getStringArray(R.array.nav_drawer_items);

        // nav drawer icons from resources
        navMenuIcons = getResources()
                .obtainTypedArray(R.array.nav_drawer_icons);

        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerList = (GridView) findViewById(R.id.list_slidermenu);

        navDrawerItems = new ArrayList<NavDrawerItem>();

        // Recycle the typed array
        navMenuIcons.recycle();

        mDrawerList.setItemChecked(0, true); // NOTE: Set 0 item as checked!
        mDrawerList.setOnItemClickListener(new SlideMenuClickListener());

        // setting the nav drawer list adapter
        adapter = new NavDrawerListAdapter(getApplicationContext(), navDrawerItems);
        mDrawerList.setAdapter(adapter);

        // enabling action bar app icon and behaving it as toggle button
        getActionBar().setDisplayHomeAsUpEnabled(true);
        //getActionBar().setHomeButtonEnabled(true);

        mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
                android.R.drawable.ic_input_delete, //nav menu toggle icon
                R.string.app_name, // nav drawer open - description for accessibility
                R.string.app_name // nav drawer close - description for accessibility
        ) {
            public void onDrawerClosed(View view) {
                getActionBar().setTitle(mTitle);
                // calling onPrepareOptionsMenu() to show action bar icons
                invalidateOptionsMenu();
            }

            public void onDrawerOpened(View drawerView) {
                getActionBar().setTitle(mDrawerTitle);
                // calling onPrepareOptionsMenu() to hide action bar icons
                invalidateOptionsMenu();
            }
        };
        mDrawerLayout.setDrawerListener(mDrawerToggle);

        if (savedInstanceState == null) {
            // on first time display view for first nav item
            displayView(0);
        }
    }

    /**
     * Slide menu item click listener
     * */
    private class SlideMenuClickListener implements ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position,
                                long id) {
            displayView(position);
            // NOTE: new item is checked now
            mDrawerList.setItemChecked(position, true);
        }
    }

    ...
}

在适配器中 - 只需检查是否选中了项目并设置相应的测试颜色：

public class NavDrawerListAdapter extends BaseAdapter {

    private Context context;
    private ArrayList<NavDrawerItem> navDrawerItems;

    public NavDrawerListAdapter(Context context, ArrayList<NavDrawerItem> navDrawerItems){
        this.context = context;
        this.navDrawerItems = navDrawerItems;
    }

    @Override
    public int getCount() {
        return navDrawerItems.size();
    }

    @Override
    public Object getItem(int position) {
        return navDrawerItems.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        if (convertView == null) {
            LayoutInflater mInflater = (LayoutInflater)
                    context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
            convertView = mInflater.inflate(R.layout.drawer_list_item, null);
        }

        // TODO: Here ViewHolder pattern can be used or
        ImageView imgIcon = (ImageView) convertView.findViewById(R.id.icon);
        TextView txtTitle = (TextView) convertView.findViewById(R.id.title);

        // NOTE: check which item is Checked an set corresponding text color
        if (((GridView)parent).isItemChecked(position)) {
            txtTitle.setTextColor(context.getResources().getColor(R.color.red));
        } else {
            txtTitle.setTextColor(context.getResources().getColor(R.color.black));
        }

        imgIcon.setImageResource(navDrawerItems.get(position).getIcon());
        txtTitle.setText(navDrawerItems.get(position).getTitle());


        return convertView;
    }
}

使用上面的代码，只有在指针向上后才会更改文本颜色（按项目时它的颜色仍将保持旧值）。如果在按下状态期间需要它来改变颜色，请在适配器中使用以下代码：

    // NOTE: check which item is Checked an set corresponding text color
    if (((GridView)parent).isItemChecked(position)) {
        //txtTitle.setTextColor(context.getResources().getColor(R.color.red));
        txtTitle.setTextColor(context.getResources().getColorStateList(R.color.red_selector));
    } else {
        //txtTitle.setTextColor(context.getResources().getColor(R.color.black));
        txtTitle.setTextColor(context.getResources().getColorStateList(R.color.black_selector));
    }

并提供 color / red_selector.xml 和 color / black_selector.xml 。例如。 color / black_selector.xml 应该采用以下方式：

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" android:color="@color/red"/>
    <item android:color="@color/black"/>
</selector>

抽屉物品在android中选择效果

1 个答案: