当BindingList中的现有项发生更改时,Listbox拒绝更新

时间:2011-04-15 22:57:47

标签: c# listbox bindinglist

为了让这项工作更加有效,我一直都疯了。

我的代码中有几个类。我将尝试在下面发布相关代码并尽可能缩短

public class ServerSettings
{
    private BindingList<Server> serverList = new BindingList<Server>();

    public ServerSettings()
    {

    }

    private void readSettings()
    {           
        string list = "/Settings/Server";
        XmlNodeList Xn = settings.SelectNodes(list);

        foreach (XmlNode xNode in Xn)
        {
            Server tmpSrv = new Server();
            for (int i=0; i<xNode.ChildNodes.Count; i++)
            {
                if(xNode.ChildNodes[i].Name == "Name")
                    tmpSrv.Name = xNode.ChildNodes[i].InnerText;
                else if(xNode.ChildNodes[i].Name == "Host")
                    tmpSrv.Host = xNode.ChildNodes[i].InnerText;
                else if(xNode.ChildNodes[i].Name == "Username")
                    tmpSrv.Username = xNode.ChildNodes[i].InnerText;
                else if(xNode.ChildNodes[i].Name == "Password")
                    tmpSrv.Password = xNode.ChildNodes[i].InnerText;
            }
            tmpSrv.ID = xNode.Attributes["ID"].Value;
            serverList.Add(tmpSrv);
        }
    }

    public BindingList<Server> getServerList()
    {
        return serverList;
    }

    public void setServer(Server srv, bool isNew)
    {
        if(isNew)
        {
            serverList.Add(srv);
            srvCount++;
        }
        else
        {
            string list = "/Settings/Server[@ID='"+srv.ID+"']";
            XmlNodeList Xn = settings.SelectNodes(list);
            if(Xn.Count == 1)
            {
                XmlNode srvNode = Xn[0];
                for (int i=0; i<srvNode.ChildNodes.Count; i++)
                {
                    if(srvNode.ChildNodes[i].Name == "Name")
                        srvNode.ChildNodes[i].InnerText = srv.Name;
                    else if(srvNode.ChildNodes[i].Name == "Host")
                        srvNode.ChildNodes[i].InnerText = srv.Host;
                    else if(srvNode.ChildNodes[i].Name == "Username")
                        srvNode.ChildNodes[i].InnerText = srv.Username;
                    else if(srvNode.ChildNodes[i].Name == "Password")
                        srvNode.ChildNodes[i].InnerText = srv.Password;
                }
            }
        }

    }
}

在另一个表单类中,我有以下函数,在程序启动时调用一次

public void populateServerListBox(ref BindingList<Server> srvList)
    {
        this.serverListBox.DisplayMember = "Name";
        this.serverListBox.DataSource = srvList;
    }

最后

public partial class NewServerForm : Form
{
    private bool _isEdit = false;
    private bool isCanceled = true;
    private Server selSrv = null;

    public NewServerForm()
    {
        InitializeComponent();
    }

    void NewServerFormOKBtClick(object sender, EventArgs e)
    {
        isCanceled = false;
        this.Close();
    }

    void NewServerFormCancelBtClick(object sender, EventArgs e)
    {
        isCanceled = true;
        this.Close();
    }

    public bool isEdit
    {
        get
        {
            return _isEdit;
        }
        set
        {
            _isEdit = value;
        }
    }

    public void showForm(ref Server srv)
    {
        selSrv = srv;
        isEdit = true;
        this.newServerFormNameTb.Text = selSrv.Name;
        this.newServerFormHostTb.Text = selSrv.Host;
        this.newServerFormUsernameTb.Text = selSrv.Username;
        this.newServerFormPwdTb.Text = selSrv.Password;
        this.ShowDialog();
    }

    public void showForm()
    {
        selSrv = new Server();
        this.ShowDialog();
    }


    void NewServerFormFormClosing(object sender, FormClosingEventArgs e)
    {           
        if(isCanceled || selSrv == null)
            this.Dispose();
        else if(isEdit && selSrv != null)
        {
            selSrv.Name = this.newServerFormNameTb.Text;
            selSrv.Host = this.newServerFormHostTb.Text;
            selSrv.Username = this.newServerFormUsernameTb.Text;
            selSrv.Password = this.newServerFormPwdTb.Text;
            selSrv.BgwConfigPath = this.newServerFormBgwlocTb.Text;
            isCanceled = true;
            MainProgram.serverSettings.setServer(selSrv, false);
            this.Dispose();
        }
        else if(selSrv != null)
        {
            selSrv.Name = this.newServerFormNameTb.Text;
            selSrv.Host = this.newServerFormHostTb.Text;
            selSrv.Username = this.newServerFormUsernameTb.Text;
            selSrv.Password = this.newServerFormPwdTb.Text;

            MainProgram.serverSettings.setServer(selSrv, true);
            isCanceled = true;
            this.Dispose();
        }
    }
}

我正在尝试为不同的服务器构建简单的用户设置菜单,用户可以在其中添加,删除或更改现有的服务器设置。在带有列表框的表单中,用户单击一个按钮,该按钮会显示另一个表单,其中包含一些文本框供用户填写,然后单击“确定”以执行更改。

这些更改反映在bindingList中的Items(新项目或现有项目的更新)中。添加新的服务器项或从bindingList中删除一个会立即反映在列表框中,但是对现有项的更改将拒绝更新列表框。关闭包含列表框的表单并再次打开它将显示更改,但是当在列表框中完成更改时,我无法立即使用它。

我试过在列表框上调用refresh(),在BindingList上调用resetBindings()以及其他几个。

我在这里错过了什么吗?

1 个答案:

答案 0 :(得分:8)

一个脏修复和已知的列表框微软错误:我们每次都需要刷新框内容设置datasource = null,然后重新绑定它。

它没有更新的原因是因为列表中的对象没有改变,它只检查对象的引用而不是它们的内容。

<强> [编辑]

正确的方法是在“Server”类上实现INotifyPropertyChanged接口。让我给你一些参考资料。

http://msdn.microsoft.com/en-us/library/system.componentmodel.inotifypropertychanged(v=VS.80).aspx

http://www.gavaghan.org/blog/2007/07/17/use-inotifypropertychanged-with-bindinglist/

http://www.codeproject.com/KB/cs/BindBetterINotifyProperty.aspx

how to update listbox items with INotifyPropertyChanged