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我有一个包含个人信息的表格视图。信息来自 textviews 并放入一个数组中，最后以 txt 文件的形式存储在磁盘上。当一个人选择一个条目来更新我读取文件的个人信息时，将数据放回数组中并希望用原始数据填充文本视图 这是我的问题陈述。我想用文件中的数据填充文本视图。

我可以选择此人，但收到 System.NullReferenceException: Object reference not set to an instance of an object。

我正在使用来自 Xamian 和其他人的示例来填充 tableview。我的程序由公共部分类 RegistrantScreen 组成：具有文本视图和其他控件的 UIViewController。我使用 xib 创建物理接口。我的公共类 registrantTableSource ： UITableViewSource 具有常规方法 RowsinSection 和 RowSelected。我使用 RowSelected 作为方法来了解需要更新哪些人员数据。当我选择一个人时，RowSelected 会触发并开始处理。我将选定的人员索引号传回，然后读取文件并放入数组中。当我尝试使用数组数据填充文本视图时，我得到空引用异常。

以下是获取人员选择索引并传回其他类的两种方法。

    public override void RowSelected (UITableView tableView, NSIndexPath indexPath)
    {
        //myPersonSelected = new RegistrantScreen (facility);
        AnIndexSelected = true;
        //need to read the fac file so we know if on site or off site for populating the boxes.
        int person = indexPath.Row  ;
        //new UIAlertView("Row Selected", tableItems[indexPath.Row], null, "OK", null).Show(); 
        tableView.DeselectRow (indexPath, true); 
        upDateOne (person);//jump over and get the file and fill an array for the person selected.
    }//end of public override void RowSelected (UITableView tableView, NSIndexPath indexPath)



    public void upDateOne(int rowPerson)//rowPerson is the selected index of registrants.
    {
        string facilityFolder =Environment.GetFolderPath (Environment.SpecialFolder.MyDocuments);
        facilityFolder = System.IO.Path.Combine (facilityFolder , "Facilities");
        facilityFolder = System.IO.Path.Combine (facilityFolder, "tmpFacility");

        string facility = File.ReadAllText (facilityFolder);//has the name of the facility to open
        string tmpRegistrants = facility.Replace ("fac", "par");//this holds the participants information.

        facilityFolder =Environment.GetFolderPath (Environment.SpecialFolder.MyDocuments);
        facilityFolder = System.IO.Path.Combine (facilityFolder , "Facilities");
        tmpRegistrants = facility.Replace ("fac", "par");//this holds the participants information.
        facilityFolder = System.IO.Path.Combine (facilityFolder , tmpRegistrants );//should be reading the par file now.
        registrants = System.IO.File.ReadAllLines (facilityFolder);//this is the array for the selected participant.
        //string [] personToUpdate = registrants[rowPerson];
        //fillBoxes (Convert.ToString ( registrants[rowPerson]) );
        //need to populate the text boxes next.
        //need to check for commas again.
        RegistrantScreen myPersonSelected;
        myPersonSelected =  new RegistrantScreen (facility );


        //myPersonSelected .tableIndexChanged (rowPerson);
         myPersonSelected.updateForOne(rowPerson );
        ;
    }//end of public void upDateOne(int rowPerson)

这是我将数据传递到的地方。

    public void updateForOne(int person)//fill the textboxes for one person.
    {
        facilityFolder=Environment.GetFolderPath (Environment.SpecialFolder.MyDocuments);
        facilityFolder= System.IO.Path.Combine (facilityFolder, "Facilities");
        facilityName= System.IO.Path.Combine (facilityFolder, Title);
        facilityLines = System.IO.File.ReadAllLines (facilityName);//get the facility info to use for decision making.
        string participantFile = facilityName.Replace ("fac", "par");
        string [] participantList = System.IO.File.ReadAllLines (participantFile);//get all the participants

        char [] deLimChars = { ',' };
        string[] words = participantList[person].Split( deLimChars );

        RegistrantScreen myTest = new RegistrantScreen (Title );

        tbXXXXapproval.Text = words[0];  ****Null reference exception here.****

我认为我的对象被垃圾收集了，但还没有找到使我的 textview 和其他控件不为空的过程。任何帮助或指针表示赞赏。

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