Question

我正在尝试从listview和适配器以及数据库中删除一行。这是我的WebMessageAdapter.java类，我在其中调用adapter.notifyDataSetChanged（）;但它没有刷新列表。当我从其他活动回来时，列表再次填充刚刚删除的数据。我不明白我错过了什么或在哪里..？

感谢。

package com.utility;

import java.util.ArrayList;

import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.TextView;

import com.activity.ContactInfoActivity;
import com.activity.MYApplication;
import com..activity.R;
import com.database.WebMessageCore;

public class WebMessageAdapter extends ArrayAdapter<WebMessageCore> implements
        OnClickListener {

    Context _Context;
    ArrayList<WebMessageCore> _WebMsgList;
    WebMessageCore _WebMsgCore;
    TextView _MsgContent;
    private LayoutInflater mInflater;
    ImageView Arrow;
    ImageView imgDel;

    MYApplication application;
    WebMessageCore selectedWebMsgCore;

    public WebMessageAdapter(Context context, int resource,
            ArrayList<WebMessageCore> contactList) {

        super(context, resource, contactList);
        _Context = context;
        _WebMsgList = contactList;
        mInflater = LayoutInflater.from(context);
    }

    public int getCount() {
        return _WebMsgList.size();
    }

    public WebMessageCore getItem(int position) {
        return _WebMsgList.get(position);
    }

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.custom_row_view, null);
            holder = new ViewHolder();
            holder.txtName = (TextView) convertView.findViewById(R.id.name);
            holder.txtmessage = (TextView) convertView
                    .findViewById(R.id.meassage);
            holder.txtPhone = (TextView) convertView.findViewById(R.id.phone);
            holder.txtdate = (TextView) convertView.findViewById(R.id.datetime);
            holder.Arrow = (ImageView) convertView
                    .findViewById(R.id.settingArrow);
            holder.imgDelete = (ImageView) convertView.findViewById(R.id.dlet);

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

        _WebMsgCore = _WebMsgList.get(position);
        holder.txtName.setText(_WebMsgCore.getName());
        holder.txtmessage.setText(_WebMsgCore.getMessage());
        holder.txtPhone.setText(_WebMsgCore.getMobileNo());
        holder.txtdate.setText(_WebMsgCore.getRecDate());

        holder.imgDelete.setTag(_WebMsgCore);
        holder.imgDelete.setOnClickListener(this);
        holder.Arrow.setTag(_WebMsgCore);
        holder.Arrow.setOnClickListener(this);
        return convertView;
    }

    static class ViewHolder {
        ImageView Arrow;
        TextView txtName;
        TextView txtmessage;
        TextView txtPhone;
        TextView txtdate;
        ImageView imgDelete;

    }

    public WebMessageCore getSelectedWebMsgCore() {
        return selectedWebMsgCore;
    }

    public void setSelectedWebMsgCore(WebMessageCore selectedWebMsgCore) {
        this.selectedWebMsgCore = selectedWebMsgCore;
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.dlet:
            WebMessageCore tempWebMsgCore = (WebMessageCore) v.getTag();
            _WebMsgList.remove(tempWebMsgCore);   
            adapter.notifyDataSetChanged();
            break;
        case R.id.settingArrow:
            callContactInfoActivity(v);
            break;
        default:
            break;
        }

    }



    private void callContactInfoActivity(View v) {
        WebMessageCore tempWebMsgCore = (WebMessageCore) v.getTag();
        WebMessageAdapter.this.setSelectedWebMsgCore(tempWebMsgCore);
        Intent newActivity = new Intent(_Context, ContactInfoActivity.class);
        newActivity.putExtra("id", tempWebMsgCore.getId());
        newActivity.putExtra("name", tempWebMsgCore.getName());
        newActivity.putExtra("message", tempWebMsgCore.getMessage());
        newActivity.putExtra("mobilenumber", tempWebMsgCore.getMobileNo());
        _Context.startActivity(newActivity);
    }

}

Answer 1

更改为：

WebMessageAdapter.this.notifyDataSetChanged();

修改

删除public void onClick(View v) {}，然后更改为：

holder.imgDelete.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { _WebMsgList.remove(position); WebMessageAdapter.this.notifyDataSetChanged(); } });

Answer 2

不要在_WebMsgCore方法的holder.imgDelete.setTag(_WebMsgCore);中添加getView()的模型对象。取而代之的是在position和holder.imgDelete.setTag(position)回调方法中添加onClick()，从标记中获取位置，并从您收到的item中移除position并调用适配器的notifyDataSetChanged()。

希望这能解决您的问题。

Answer 3

你应该为convertView实现seton onclick listener，

convertView.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
    _WebMsgList.remove(position);   
    WebMessageAdapter.this.notifyDataSetChanged();
}

}）;

为什么adapter.notifyDataSetChanged（）;不管用？

3 个答案: