Question

我在Listview中创建了一个Listview我有两个Buttons和一个Edittext。在我的Edittext中，我希望根据Edittext点击增加Button的值。我按照了很多教程，但仍然无法在Listview中使用，任何人都可以帮助我吗？

我遵循本教程： http://www.androidhub4you.com/2013/02/muftitouch-listview-multi-click.html

它显示：Cannot refer to the non-final local variable holder defined in an enclosing scope

代码：

public class UserCustomAdapter extends ArrayAdapter<User> {
 Context context;
 int layoutResourceId;
 ArrayList<User> data = new ArrayList<User>();

 public UserCustomAdapter(Context context, int layoutResourceId,
   ArrayList<User> data) {
  super(context, layoutResourceId, data);
  this.layoutResourceId = layoutResourceId;
  this.context = context;
  this.data = data;
 }

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

  if (row == null) {
   LayoutInflater inflater = ((Activity) context).getLayoutInflater();
   row = inflater.inflate(layoutResourceId, parent, false);
   holder = new UserHolder();
   holder.textName = (TextView) row.findViewById(R.id.textView1);
   holder.textAddress = (EditText) row.findViewById(R.id.textView2);
   holder.textLocation = (TextView) row.findViewById(R.id.textView3);
   holder.btnEdit = (Button) row.findViewById(R.id.button1);
   holder.btnDelete = (Button) row.findViewById(R.id.button2);
   row.setTag(holder);
  } else {
   holder = (UserHolder) row.getTag();
  }
  User user = data.get(position);
  holder.textName.setText(user.getName());
  //holder.textAddress.setText(user.getAddress());
  holder.textLocation.setText(user.getLocation());
  holder.btnEdit.setOnClickListener(new OnClickListener() {

   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    Log.i("Edit Button Clicked", "**********");
   /* Toast.makeText(context, "Edit button Clicked",
      Toast.LENGTH_LONG).show();*/

    int mValue = Integer.parseInt(holder.textAddress.getText().toString());
    mValue--;
    if(mValue < 0)
    {
        System.out.println("not valid");
    }
    else
    {
        holder.textAddress.setText( ""+mValue );
    }
   }
  });
  holder.btnDelete.setOnClickListener(new OnClickListener() {

   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    Log.i("Delete Button Clicked", "**********");
   /* Toast.makeText(context, "Delete button Clicked",
      Toast.LENGTH_LONG).show();*/
   }
  });
  return row;

 }

 static class UserHolder {
  TextView textName;
  EditText textAddress;
  TextView textLocation;
  Button btnEdit;
  Button btnDelete;
 }
}

Answer 1

在这种情况下，您无法访问使用局部变量，在调用onClickListener时，变量将超出范围。

因此您可以将ViewHolder设置为按钮的标记，然后您可以在onClick中访问它。

holder.btnEdit.setTag(holder);
holder.btnEdit.setOnClickListener(new OnClickListener() {

   @Override
   public void onClick(View v) {
     ViewHolder tagHolder = (ViewHolder) v.getTag();

    // TODO Auto-generated method stub
    Log.i("Edit Button Clicked", "**********");
   /* Toast.makeText(context, "Edit button Clicked",
      Toast.LENGTH_LONG).show();*/

    int mValue = Integer.parseInt(tagHolder.textAddress.getText().toString());
    mValue--;
    if(mValue < 0)
    {
        System.out.println("not valid");
    }
    else
    {
        tagHolder.textAddress.setText( ""+mValue );
    }
   }
  });

我希望它有所帮助！

Answer 2

修改

尝试声明像这样的持有者，不要试图在代码中重新声明它。

final UserHolder holder = new UserHolder();

最终变量无法重新分配

Answer 3

使用final UserHolder holder;代替UserHolder holder = new UserHolder()。

如何在listview的每一行中增加或减少edittext的值？

3 个答案: