Question

我已经读过这个令人困惑的材料，＆＃34; listview滚动丢失的内容＆＃34;这让我感到沮丧。所以我决定在这里问。这就是我需要的：

(TextItems)  (TextValue)
Item1            0 
Item2            0
Item3            0
// after input custom edittext dialog, It must be:
Item1            3
Item2            8
Item3            5

但是，在我向下滚动屏幕后（屏幕上没有显示3个项目）然后再次向上滚动，这些项目值又回到0.这是我的Main.java：

String[] items = {"Item1","Item2","Item3","Item4",..,"Item30"};

final ListView listView = (ListView)findViewById(R.id.listItems); 
ArrayAdapter<String> adapter = new LVAdapter(this, items);
listView.setAdapter(adapter);

listView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, final View view,
                    int position, long id) {

                AlertDialog.Builder alert = new AlertDialog.Builder(Main.this);
                LayoutInflater inflater = Main.this.getLayoutInflater();
                View v = inflater.inflate(R.layout.input_dialog, null);
                alert.setView(v);

                final EditText userInput = (EditText)v.findViewById(R.id.editInput);
                alert.setPositiveButton("OK", new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        TextView tv = (TextView)view.findViewById(R.id.textValue); // for giving value on each Items
                        tv.setText(userInput.getText());
                    }
                });

                AlertDialog al = alert.create();
                al.show();
            }
        });

然后，它是我的LVAdapter.java

public class LVAdapter extends ArrayAdapter<String> {

private final Context context;
private final String[] val;

public LVAdapter(Context context, String[] val) {
    super(context, R.layout.detail_item, val);
    this.context = context;
    this.val = val;
}

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

    LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View v = inflater.inflate(R.layout.detail_item, parent, false);

    TextView tv = (TextView)v.findViewById(R.id.textItems); //for storing Item1, Item2, .., etc.
    tv.setText(val[position]);

    return v;
}

main.xml中

<ListView
    android:id="@+id/listItems"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:descendantFocusability="afterDescendants" >
</ListView>

及其main_items.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <TextView
        android:id="@+id/textItems"
        android:layout_width="250dp"
        android:layout_height="wrap_content"
        android:text="TextView"
        android:layout_alignParentLeft="true"
        android:padding="5dp"
        android:textAppearance="?android:attr/textAppearanceMedium" />

<!-- I need to set this textView based on users input -->
    <TextView
        android:id="@+id/textValue"
        android:layout_width="60dp"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:layout_alignParentRight="true"
        android:text="0"
        android:padding="5dp"
        android:textAppearance="?android:attr/textAppearanceMedium" />

</RelativeLayout>

我在这里。堆叠如何实现＆＃34;它叫什么＆＃34;为了保持我的价值，即使我在屏幕上滚动。提前谢谢。

Answer 1

ListView正在回收其子视图，并且不会自动保存您的输入。这意味着你必须自己做肮脏的工作。首先保存输入然后检索它并将其显示在正确的位置。堆栈上有一些答案你可以查看，但无论如何这里是我使用的代码：

    public class ArrayListAdapter extends BaseAdapter{
    ArrayList<Product> productlist= null;
    private  Activity context=null;


    public ArrayListAdapter(Activity context, ArrayList<Product> objects) {
        this.productlist= objects;
        this.context=context;
    }

    static class ViewHolder{
        TextView textvw;
        EditText edittx;
        int ref;
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        if(productlist!=null&&productlist.size()>0)
            return productlist.size();
        return 1;
    }

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

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        final ViewHolder holder;
        if (convertView==null){
            holder= new ViewHolder();
            LayoutInflater inflater = context.getLayoutInflater();
            convertView=inflater.inflate(R.layout.list_item, null);
            holder.textvw =(TextView)convertView.findViewById(R.id.name);
            holder.edittx =(EditText)convertView.findViewById(R.id.quantity);
            convertView.setTag(holder);


        }else
        {
            holder=(ViewHolder)convertView.getTag();
        }

        holder.ref=position;
        holder.textvw.setText(productlist.get(position).name);
        holder.edittx.setText(productlist.get(position).quantity);

        holder.edittx.addTextChangedListener(new TextWatcher() {

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                // TODO Auto-generated method stub

            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                // TODO Auto-generated method stub

            }

            @Override
            public void afterTextChanged(Editable s) {
                // TODO Auto-generated method stub
                productlist.get(holder.ref).quantity= s.toString();
productlist.get(holder.ref).quantity);
productlist.get(holder.ref+1).quantity );


            }
        });
        return convertView;
    }

}

Answer 2

您需要将输入的值设置为传递给适配器的列表或数组。

像这样：

listView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, final View view,
                    int position, long id) {

                AlertDialog.Builder alert = new AlertDialog.Builder(Main.this);
                LayoutInflater inflater = Main.this.getLayoutInflater();
                View v = inflater.inflate(R.layout.input_dialog, null);
                alert.setView(v);

                final EditText userInput = (EditText)v.findViewById(R.id.editInput);
                alert.setPositiveButton("OK", new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                       // Don't set text view item here
                       // Here you need to set value to your array or list which you passed to adapter for listview
                       items[position] = userInput.getText().toString();
                       adapter.notifyDataSetChanged(); // Use this for reflects the entered value
                    }
                });

                AlertDialog al = alert.create();
                al.show();
            }
        });

Answer 3

错误在你的getView方法中。你需要像这样修改你的getView

@Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView == null){
            holder = new ViewHolder();
            LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            View v = inflater.inflate(R.layout.detail_item, parent, false);
            holder. tv = (TextView)v.findViewById(R.id.textItems); 
            convertView.setTag(holder);
        }else{
            holder = (ViewHolder) convertView.getTag();
        }



        holder. tv.setText(val[position]);

        return v;
    }

还添加持有者类

class ViewHolder {
        TextView tv;
    }

Answer 4

创建视图的Hashmap并在其中添加listview项视图，如果您的项已经存在于hashmap中则滚动，然后从hashmap中检索该项。这不会导致您的内容丢失。

HashMap<Integer, View> hashMap = new HashMap<Integer, View>();


public View getView(final int position, View view, ViewGroup parent)
 {
    final ViewHolder holder;
    if (hashMap.containsKey(position)) {
        return hashMap.get(position);
    }
    holder = new ViewHolder();
    view = inflater.inflate(R.layout.detail_item, null);

    // set tag and put views in hashmap
    view.setTag(holder);
    hashMap.put(position, view);

    return view;
}

希望这会奏效......谢谢

保持listview滚动中的textview内容

4 个答案: