Question

我正在使用自定义列表视图，在运行应用程序后，一切正常，但在滚动列表时，视图变得混乱。我已粘贴屏幕截图，然后是下面的代码。

我该如何解决这个问题？

初始屏幕：

enter image description here

滚动之后和之后： enter image description here

MyList.java：

import java.util.ArrayList;

import android.content.Context;
import android.graphics.Typeface;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

public class MyList extends Fragment {

    ListView list;
    MediaPlayer mp;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedinstanceState)
    {
        mp=MediaPlayer.create(getActivity(), R.raw.wave1);

        return inflater.inflate(R.layout.mylistview, container, false);

    }

    @Override
    public void onStart() {

        super.onStart();
        list=(ListView)getView().findViewById(R.id.listView1);
        list.setAdapter(new MyListAdapter(getActivity()));


        list.setOnItemClickListener(new OnItemClickListener(){

            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1, int position,
                    long arg3) 
            {
                switch(position)
                    {
                    case 0:
                        mp.release();
                        mp=MediaPlayer.create(getActivity(), R.raw.wave1);
                        mp.start(); 

                    break;

                    case 1:
                        mp.release();
                        mp=MediaPlayer.create(getActivity(), R.raw.wave2);
                        mp.start(); 
                        break;

                    case 2:
                        mp.release();
                        mp=MediaPlayer.create(getActivity(), R.raw.wave3);
                        mp.start();     
                        break;

                    case 3:
                        mp.release();
                        mp=MediaPlayer.create(getActivity(), R.raw.wave4);
                        mp.start(); 
                        break;

                    case 4:
                        mp.release();
                        mp=MediaPlayer.create(getActivity(), R.raw.wave5);
                        mp.start(); 
                        break;
                    }

             }
            });
    }
}

    class MyListAdapter extends BaseAdapter
    {
        ArrayList<SingleRow> list;
        Context context;
        MyListAdapter(Context c)
        {
            context=c;
            list=new ArrayList<SingleRow>();

        //  Resources res=c.getResources();
        //  String[] text=res.getStringArray(R.array.text);

            int[] images={R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                    R.drawable.ic_launcher,
                        };
            for(int i=0;i<19;i++)
            {
                list.add(new SingleRow(images[i]));
            }
        }

        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return list.size();
        }

        @Override
        public Object getItem(int position) {
            // TODO Auto-generated method stub
            return list.get(position);
        }

        @Override
        public long getItemId(int position) {

            return position;
        }

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


            LayoutInflater inflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            View row1=inflater.inflate(R.layout.mylist_rows, parent, false);
            TextView text=(TextView)row1.findViewById(R.id.textView1);
            ImageView image=(ImageView)row1.findViewById(R.id.imageView1);

            SingleRow temp=list.get(position);

            text.setText(temp.description);
            image.setImageResource(temp.image);

            Typeface font = Typeface.createFromAsset(text.getContext().getAssets(), "fonts/OpenSans.ttf");

            text.setTypeface(font);

            return row1;
        }


    class SingleRow
    {
        String description;
        int image;
        SingleRow( int image)
        {
            //this.description=description;
            this.image=image;
        }
    }

    }

MainActivity.java：

import java.util.ArrayList;

import android.content.res.Configuration;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.widget.DrawerLayout;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;

public class MainActivity extends FragmentActivity {
    private DrawerLayout mDrawerLayout;
    private ListView 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;

    @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 = (ListView) 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_navigation_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);
        }
    }

    @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) {

        Fragment fragment = null;
        // update the main content by replacing fragments
        switch (position) {
        case 0:
            fragment = new MyList();
            break;  

        } 

        if (fragment != null) {
        android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
        fragmentManager.beginTransaction()
        .replace(R.id.frame_container, fragment).commit();

        mDrawerList.setItemChecked(position, true);
        mDrawerList.setSelection(position);
        setTitle(navMenuTitles[position]);
        mDrawerLayout.closeDrawer(mDrawerList);
        } 

    }

    @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);
    }

}

Answer 1

更新您的getView()方法，它会更快地运行。

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row1 = null;

        if(convertView == null){
            LayoutInflater inflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            View row1=inflater.inflate(R.layout.mylist_rows, parent, false);
        }else{
            row1 = convertView;
        }
        TextView text=(TextView)row1.findViewById(R.id.textView1);
        ImageView image=(ImageView)row1.findViewById(R.id.imageView1);

        SingleRow temp=list.get(position);

        text.setText(temp.description);
        image.setImageResource(temp.image);

        Typeface font = Typeface.createFromAsset(text.getContext().getAssets(), "fonts/OpenSans.ttf");

        text.setTypeface(font);

        return row1;
    }

你也可以优化一些东西：

1如果您的图片始终相同，则可以将代码放入if阻止

if(convertView == null){
    LayoutInflater inflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View row1=inflater.inflate(R.layout.mylist_rows, parent, false);

    ImageView image=(ImageView)row1.findViewById(R.id.imageView1);

    SingleRow temp=list.get(position);
    image.setImageResource(temp.image);
}else{

2如果您的字体始终相同，您也可以将其放入if阻止

if(convertView == null){
    // inflating...

    TextView text=(TextView)row1.findViewById(R.id.textView1);
    Typeface font = Typeface.createFromAsset(text.getContext().getAssets(), "fonts/OpenSans.ttf");

    text.setTypeface(font);
}else{

Answer 2

尝试

list.setCacheColorHint(Color.TRANSPARENT);

Answer 3

修改你的getView（）：

 @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View row1 = null;

            if(convertView == null){
                LayoutInflater inflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                View row1=inflater.inflate(R.layout.mylist_rows, parent, false);
                convertView.setTag(row1);
            }else{
                 row1= (View) convertView.getTag();
            }
            TextView text=(TextView)row1.findViewById(R.id.textView1);
            ImageView image=(ImageView)row1.findViewById(R.id.imageView1);

            SingleRow temp=list.get(position);

    text.setText(temp.description);
    image.setImageResource(temp.image);

    Typeface font = Typeface.createFromAsset(text.getContext().getAssets(), "fonts/OpenSans.ttf");

    text.setTypeface(font);

    return row1;
}

让我知道它是否会起作用。

Answer 4

解决。事实证明我有两个片段声明。 activitymain.xml中的一个标记声明和MainActivity.java中的片段事务。根据{{3}} ，您可以在其中任何一个中声明片段，但不能同时声明两者。这就是我获得双重观点的原因。

滚动列表视图时在后台重复

4 个答案: