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我使用自定义列表视图,并在运行应用程序后,一切工作正常,但滚动列表时,视图变得混乱。我粘贴了屏幕截图,后面是下面的代码。解决方法:在滚动列表视图时重复列表视图

我该如何解决这个问题?

初始屏幕:

enter image description here

后和滚动时: 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); 
    } 

} 
+0

发布你的活动代码,承载这个片段 – Geros

+0

当然,我马上发布它。 – sabergeek

+0

将标记设置为convertview。 –

回答

0

更新您的getView()方法,将更加快捷。

@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; 
    } 

您还可以优化一些事情:

1,如果你的形象将始终是相同的,你可以把代码,如果你对你的字体将始终是相同的,以if

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你也可以把它写到if区块

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{ 
+0

谢谢罗马。我尝试了代码,但在“convertView = null”处得到红线,表示类型不匹配:无法从视图转换为布尔值。此外,图像将保持不变,但每个列表项目上的文字都不相同。 – sabergeek

+0

对不起,用convertView == null替换。 –

+0

我已更新我的帖子 –

0

试试

list.setCacheColorHint(Color.TRANSPARENT); 
0

修改您的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,如果它不会工作。

+0

我试过你分享的代码。该应用程序与NullPointer崩溃。然而,在运行应用程序之前,编译器警告有关convertView.setTag(row1)的内容为“空指针访问:变量convertView只能在此位置为null” – sabergeek

+0

更改:'查看row1 = null;'将'SingleRow row1 = new SingleRow();' –

+0

在新的SingleRow()**上出现红线,说“构造函数MyListAdapter.SingleRow()未定义”。到处使用row1的红线。 – sabergeek