Listview中的Imageview无法在运行时更改android

我正在开发Android应用程序。其中我有列表视图与文字和图像。我需要在运行时将imageview设置为可见。即。当我点击视图时，它应该出现，当我点击下一个视图之前的视图必须消失，并且点击视图中的相应图像视图必须出现。Listview中的Imageview无法在运行时更改android

现在，我成功地显示文字，但我在图像视图的外观屡次。在项目列表的onclick内我无法设置图像视图的资源

以下是我的代码。

public class ListofCategory extends Activity{ 
ListView listview; 
List<String> mycategoryId,mycategoryName; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    requestWindowFeature(Window.FEATURE_NO_TITLE); 
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
          WindowManager.LayoutParams.FLAG_FULLSCREEN); 
    setContentView(R.layout.listofcategory); 
    listview=(ListView)findViewById(R.id.category_listview); 
    mycategoryId=new ArrayList<String>(); 
    mycategoryName=new ArrayList<String>(); 
    getData(); 
    listview.setAdapter(new MyListAdapter(this)); 
    //setListAdapter(new MyListAdapter(this)); 
} 

    class MyListAdapter extends BaseAdapter{ 
private Context context; 

MyListAdapter(Context context) 
{ 
    this.context=context; 

} 

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

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

@Override 
public long getItemId(int position) { 
    // TODO Auto-generated method stub 
    return position; 
} 


@Override 
public View getView(final int position, View view, ViewGroup viewgroup) { 

    ViewHolder holder = null; 
    LayoutInflater inflater = LayoutInflater.from(context); 
      if (view == null) 
      { 

       view = inflater.inflate(R.layout.mycategorylist, null); 
    holder = new ViewHolder(); 
    holder.categoryname = (TextView) view.findViewById(R.id.title); 
    holder.categorycount = (TextView) view.findViewById(R.id.description); 
    holder.arrow=(ImageView)view.findViewById(R.id.arrow_imageview); 
    view.setTag(holder); 
} 
else 
{ 
    holder = (ViewHolder) view.getTag(); 
} 
    holder.categoryname.setText(mycategoryName.get(position)); 
    holder.categoryname.setTextSize(18.0f); 
    //holder.arrow.setImageResource(R.drawable.arrow); 

    view.setOnClickListener(new OnClickListener() { 

     @Override 
     public void onClick(View v) 
     { 
      Problem occurs here.. This holder value ask me to change as final but here i cannot make holder to final 
      holder.arrow.setImageResource(R.drawable.arrow); 
      //finish(); 

     } 
    }); 

return view; 
} 


    } 
class ViewHolder 
{ 
    TextView categoryname; 
    TextView categorycount; 
    ImageView arrow; 

} 

    }

请人给我一个更好的solution..its非常紧迫的..谢谢提前

来源

2011-11-02 deepa

创建的ImageView的最终指针。

final ImageView tempView = holder.arrow;

比在onclick：

tempView.setImageResource(R.drawable.arrow);

添加到类中的字段：

MyListAdapter myAdapter;

在OnCreate方法做到这一点：

myAdapter = new MyListAdapter(this); 
listview.setAdapter(myAdapter);

上的onclick事件做到这一点：

view.setOnClickListener(new OnClickListener() {  

    @Override  
    public void onClick(View v)  
    {  
     Problem occurs here.. This holder value ask me to change as final but here i cannot make holder to final  
     tempView.setImageResource(R.drawable.arrow);  
     myAdapter.notifyDataSetChange();  

    }  
});

这应该工作。

来源

2011-11-02 10:22:13 Raz

感谢您的答复。虽然使用此代码最终问题已解决，但当我点击另一个列表项时，前一个可见的图像也可见。 – deepa

您需要调用adapter.NotifiyDataSetChange（）才能自行刷新数据。 – Raz

我必须使用adapter.NotifiyDataSetChange（）。因为我没有拿适配器的对象。当我重写notifiyDatasetChange它保持相同.. – deepa

至于我能理解，

我想，而不是使用使用，这是在R.layout.mycategorylist使用layout onClickListener。

否则，您可以使用holder.categoryname onClickListener或holder.categorycount listeners的权利。

你可以声明ViewHolder holder ; as global variable in your MyListAdapter没错，那么宣布final什么都没有问题。

希望它可以帮助

来源

2011-11-02 10:22:27 Udaykiran

试试这个：

ViewHolder tmpHolder = null; 
if(view == null) { 
    . 
    . 
    . 
    tmpHolder = new ViewHolder(); 
} else { 
    tmpHolder = (ViewHolder) view.getTag(); 
} 
final ViewHolder holder = tmpHolder; 

view.setOnClickListener(new OnClickListener() { 

    @Override 
    public void onClick(View v) 
    { 
     holder.arrow.setImageResource(R.drawable.arrow); 
     //finish(); 

    } 
});

来源

2011-11-02 10:23:00

public void onItemClick(AdapterView<?> arg0, View view, int position, 
       long id) { 
      // TODO Auto-generated method stub 


      ImageView image; 
      RelativeLayout layout = (RelativeLayout) view;//Layout of mycategorylist 
      image = (ImageView) layout.getChildAt(0);//image is added first here.change accordingly 
      image.setImageDrawable(....imageId); 

    }

来源

2011-11-02 10:24:10 Rasel

上面的代码添加图像的所有列表视图..以前的图像没有删除... – deepa

 public class ListofCategory extends Activity{ 
ListView listview; 
List<String> mycategoryId,mycategoryName; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    requestWindowFeature(Window.FEATURE_NO_TITLE); 
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
          WindowManager.LayoutParams.FLAG_FULLSCREEN); 
    setContentView(R.layout.listofcategory); 
    listview=(ListView)findViewById(R.id.category_listview); 
    mycategoryId=new ArrayList<String>(); 
    mycategoryName=new ArrayList<String>(); 
    getData(); 
    listview.setAdapter(new MyListAdapter(this)); 
    //setListAdapter(new MyListAdapter(this)); 
} 

    class MyListAdapter extends BaseAdapter{ 
private Context context; 
private ImageView previous; 

MyListAdapter(Context context) 
{ 
    this.context=context; 

} 

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

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

@Override 
public long getItemId(int position) { 
    // TODO Auto-generated method stub 
    return position; 
} 


@Override 
public View getView(final int position, View view, ViewGroup viewgroup) { 

    ViewHolder holder = null; 
    LayoutInflater inflater = LayoutInflater.from(context); 
      if (view == null) 
      { 

       view = inflater.inflate(R.layout.mycategorylist, null); 
    holder = new ViewHolder(); 
    holder.categoryname = (TextView) view.findViewById(R.id.title); 
    holder.categorycount = (TextView) view.findViewById(R.id.description); 
    holder.arrow=(ImageView)view.findViewById(R.id.arrow_imageview); 
    view.setTag(holder); 
} 
else 
{ 
    holder = (ViewHolder) view.getTag(); 
} 
    holder.categoryname.setText(mycategoryName.get(position)); 
    holder.categoryname.setTextSize(18.0f); 
    //holder.arrow.setImageResource(R.drawable.arrow); 

    view.setOnClickListener(new OnClickListener() { 

     @Override 
     public void onClick(View v) 
     { 

      if(previous!=null){ 

       previous.setVisibility(View.Invisible); 
       v.setVisibility(View.Visible); 
       previous = v; 
     } 
     } 
    }); 

return view; 
} 


    } 
class ViewHolder 
{ 
    TextView categoryname; 
    TextView categorycount; 
    ImageView arrow; 

}

来源

2011-11-02 10:26:43 viv

在上面的代码之前是空的..因为没有imageview被分配到以前。 – deepa

是的第一次 – viv

它是如何进入下一次的条件下..因为没有以前的任务.. – deepa

Listview中的Imageview无法在运行时更改android

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