如何在基本适配器中使用进度对话框

Question

我有一个带有一些文本视图和一个按钮的自定义列表视图。单击按钮我想将列表视图值保存到服务器，为了完成此任务我正在使用 asyntask 但我的代码在 pregress 对话框中崩溃了。我在如何通过 activity 的实例以使用进度对话框

时遇到问题

  public class ListViewAdapter extends BaseAdapter{

  Context context;
  public arrayList<Planning> arraylist;
  private static LayoutInflater inflater = null;
  public PlanningList_activity planActivity;
  public ListView mListview;
  Db_sqlite databaseHelper;

  public ListViewAdapter(Context context,ArrayList<Plan>  arraylist) {
    this.context = context;
    this.planArraylist = plan0Arraylist;
    inflater = (LayoutInflater)      context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    databaseHelper = new Db_sqlite(context);
 }
 @Override
public int getCount() {
    return planArraylist.size();
}

@Override
public Planning getItem(int arg0) {
    return planArraylist.get(arg0);
} 

@Override
public long getItemId(int arg0) {
    return arg0;
}


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

        if (convertView == null) {
            convertView = inflater.inflate(R.layout.single_lv_item, parent, false);

            holder = new ViewHolder();


            holder.tvdrCode = (TextView convertView.findViewById(R.id.Plan_no);
            holder.tvDrName = (TextView) convertView.findViewById(R.id.doc_name);
            holder.tvterrcode= (TextView) convertView.findViewById(R.id.mon);
            holder.tvAdr = (TextView) convertView.findViewById(R.id.adr);
            holder.tvClassDesc = (TextView) convertView.findViewById(R.id.class_desc);
            holder.tvspeciality = (TextView) convertView.findViewById(R.id.ff_code);
            holder.tvAreaName = (TextView) convertView.findViewById(R.id.area_name);
            holder.tvShift = (TextView) convertView.findViewById(R.id.shift);
            holder.btn_visited =(Button)convertView.findViewById(R.id.button1);
            holder.btn_visited.setTag(position);
            holder.btn_visited.setOnClickListener(ButtonClickListener);
            convertView.setTag(holder);

        } 

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

        Planning p = planArraylist.get(position);
        holder.tvdrCode.setText(p.getDocCode());
        holder.tvDrName.setText(p.getDocName());
        holder.tvterrcode.setText(p.getTerrCode());
        holder.tvAdr.setText(p.getAdr());
        holder.tvClassDesc.setText(p.getClassDesc());
        holder.tvspeciality.setText(p.getSP());
        holder.tvAreaName.setText(p.getAreaName());
        holder.tvShift.setText(p.getMornEven());

        return convertView;
    }

     static class ViewHolder {
         TextView tvdrCode;
         TextView tvDrName;
         TextView tvterrcode;
         TextView tvAdr;
         TextView tvClassDesc;
         TextView tvspeciality;
         TextView tvAreaName;
         TextView tvShift;
         Button btn_visited;    
    }

Answer 1

可能 context 是 null 。使用您在 SaveDCR class 构造函数中传递的 mContext 来创建进度条：

      @Override
      protected void onPreExecute() {
          progressDialog = new ProgressDialog(mContext);
          progressDialog.setMessage("Saving...");
          progressDialog.setCancelable(false);
          progressDialog.show();
          Log.e( "sending dvr to sqlite","yes"); 

      }

从按钮点击传递上下文为：

new SaveDCR(v.getContext()).execute(dvr);

如何在基本适配器中使用进度对话框

how to use progress dialog in base adapter

java

android

listview

progressdialog

android-asynctask