Android - 适配器创建多行而不是一行

Question

我有一个 GUI，供用户在插入 2 个值后添加行。将添加一行，同时显示用户添加的 2 个值。但显然它创建的行数比预期的要多。例如，单击 1 次可以创建 5 行，而本应仅创建 1 行。

下一个问题是适配器用较新的值覆盖旧值，而不是创建新行。

总结一下面临的问题：

1) 适配器创建多行而不是一行。

2) 适配器用新行覆盖旧行。

有什么解决办法吗？

main.java

public class BillSplitter extends Activity{

ListView list;

Button calculate;
EditText result;
String total;
String name;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    final Spinner spinner = (Spinner)findViewById(R.id.spinner);
    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
            this, R.array.spinner_array, android.R.layout.simple_spinner_item);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(adapter);

    list = (ListView)findViewById(R.id.noteList);

    final EditText price = (EditText)findViewById(R.id.price);
    final EditText name1 = (EditText)findViewById(R.id.name);

    Button btnSimple = (Button)findViewById(R.id.btnSimple);        

    btnSimple.setOnClickListener(new OnClickListener() {
        public void onClick(View v)
        {               
            double totalPrice = Double.parseDouble(price.getText().toString());
            int position = spinner.getSelectedItemPosition();
            String namename = "";
            String totaltotal = "";
            namename = name1.getText().toString();


            if(position == 0)
            {
                totalPrice = totalPrice * 1.07;
                roundTwoDecimals(totalPrice);
                total = String.valueOf(totalPrice);
                System.out.println(total);
                //result.setText(total); 
            }
            else
            {
                totalPrice = (totalPrice * 1.1)*1.07;
                roundTwoDecimals(totalPrice);
                total = String.valueOf(totalPrice);                 
                System.out.println(total);
                //result.setText(total); 
            }
            /*noteList.add(0, total);
            System.out.println(total);
            name1.setText("");
            price.setText("");
            aa.notifyDataSetChanged();*/
            price.setText("");
            name1.setText("");
            Adapter adapter = new Adapter(main.this, name, total);
            list.setAdapter(adapter);
        }           
    });        

}

void roundTwoDecimals(double d) {
    DecimalFormat twoDForm = new DecimalFormat("#.##");
    twoDForm.format(d);

  }
}

适配器.java

public class Adapter extends BaseAdapter {

private Activity activity;
private String result;
private String text;
private static LayoutInflater inflater=null;

public Adapter(Activity a, String d, String t) {
    activity = a;
    text=d;
    result = t;
    inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

public int getCount() {
    return result.length();
}    

public Object getItem(int position) {
    return position;
}

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

public static class ViewHolder{
    public TextView text;
    public EditText edittext;

}

public View getView(int position, View convertView, ViewGroup parent) {
    View vi=convertView;
    ViewHolder holder;
    if(convertView==null){
        vi = inflater.inflate(R.layout.custom_list_item, null);
        holder=new ViewHolder();
        holder.text=(TextView)vi.findViewById(R.id.nametv);;
        holder.edittext=(EditText)vi.findViewById(R.id.result);;
        vi.setTag(holder);

    }
    else

    holder=(ViewHolder)vi.getTag();
    holder.text.setText(text);
    holder.edittext.setText(result);
    return vi;
}
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>

<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:gravity="center">

<EditText
android:id="@+id/name"
android:layout_width="125dp" 
android:layout_height="wrap_content"
android:hint="Name"
android:maxLength="10"
/>

<EditText
android:id="@+id/price"
android:layout_width="80dp" 
android:layout_height="wrap_content"
android:hint="Price"
android:inputType="numberDecimal"
android:maxLength="5"
/>

</LinearLayout>

<Button
android:id="@+id/btnSimple"
android:layout_width="wrap_content" 
android:layout_height="wrap_content"
android:text="Add"
/>

<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center">

<ListView
android:id="@+id/noteList"
android:layout_width="fill_parent" 
android:layout_height="fill_parent"
/>
</LinearLayout>

Answer 1

 Private class DetailBean{
    private String name;
    private double price;
    /// Getter and Setter methods....
    }

现在活动发生了变化......

public class BillSplitter extends Activity{ 

ListView listView; 

Button calculate; 
EditText result; 
String total; 
String name; 
private ArrayList<DetailBean> list;
private DetailBean entry;

public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 

    final Spinner spinner = (Spinner)findViewById(R.id.spinner); 
    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource( 
            this, R.array.spinner_array, android.R.layout.simple_spinner_item); 
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
    spinner.setAdapter(adapter); 

    listView = (ListView)findViewById(R.id.noteList); 

list = new ArrayList<DetailBean>();
CorrectedAdapter  adapter = new CorrectedAdapter (main.this,list); 
            listView.setAdapter(adapter); 

    final EditText price = (EditText)findViewById(R.id.price); 
    final EditText name1 = (EditText)findViewById(R.id.name); 

    Button btnSimple = (Button)findViewById(R.id.btnSimple);         

    btnSimple.setOnClickListener(new OnClickListener() { 
        public void onClick(View v) 
        {                            
            double totalPrice = Double.parseDouble(price.getText().toString());             
            int position = spinner.getSelectedItemPosition();             
            String namename = "";             
            String totaltotal = "";   
entry = new  DetailBean();          
            namename = name1.getText().toString();             


            if(position == 0)             
            {             
                totalPrice = totalPrice * 1.07;             
                roundTwoDecimals(totalPrice);             
                total = String.valueOf(totalPrice);             
                System.out.println(total);             
                //result.setText(total);              
            }             
            else             
            {             
                totalPrice = (totalPrice * 1.1)*1.07;             
                roundTwoDecimals(totalPrice);             
                total = String.valueOf(totalPrice);                              
                System.out.println(total);             
                //result.setText(total);              
            }             
            /*noteList.add(0, total);             
            System.out.println(total);             
            name1.setText("");             
            price.setText("");             
            aa.notifyDataSetChanged();*/             
            price.setText("");             
            name1.setText("");             
entry.setName(name);
entry.setPrice(total);
list.add(entry);
adapter.notifyDataSetChanged();             
        }                        
    });                     

void roundTwoDecimals(double d) { 
    DecimalFormat twoDForm = new DecimalFormat("#.##"); 
    twoDForm.format(d); 

  } 
} 

现在来主要修正Adpater......

public class CorrectedAdapter extends BaseAdapter {                

private Activity activity;                
private ArrayList<DetailBean> list;
private DetailBean entry;
private static LayoutInflater inflater=null;                

public Adapter(Activity a,ArrayList<DetailBean> l) {                
    activity = a;                
   list=l;
    inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);                
}                

public int getCount() {                
    return list.length();                
}                    

public Object getItem(int position) {                
    return position;                
}                

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

public static class ViewHolder{                
    public TextView text;                
    public EditText edittext;                

}                

public View getView(int position, View convertView, ViewGroup parent) {                
entry = list.get(position);    
View vi=convertView;                
    ViewHolder holder;                
    if(convertView==null){                
       convertView = inflater.inflate(R.layout.custom_list_item, null);                
        holder=new ViewHolder();                
        holder.text=(TextView) convertView.findViewById(R.id.nametv);;                
        holder.edittext=(EditText) convertView.findViewById(R.id.result);;                
       convertView setTag(holder);                

    }                
    else               
{ 

    holder=(ViewHolder) convertView getTag();                
}  
  holder.text.setText(entry.getName);                
    holder.edittext.setText(entry.getPrice);                
    return convertView;                
}                
}                

Answer 2

您的适配器实现是错误的。您的适配器类中应该有一个结果列表。您可能需要再次检查适配器代码。

http://mylifewithandroid.blogspot.com/2008/04/custom-widget -adapters.html

http://techdroid.kbeanie.com/2009/07/custom-listview-for-android.html

Answer 3

这个适配器不能与 Spinner 一起使用。我对此很确定。如果您想要那种设计，那么
采用一个自定义对话框。在自定义对话框中采用列表视图，然后将此适配器设置为列表视图。
这也会弹出像微调器一样的对话框。如果您对此感兴趣，那么我也可以通过编辑这个问题为您提供代码