Question

更新：现已解决，请参阅下面的答案。

在我的一个表单上（在Windows窗体应用程序中）我有3个组合框。这些组合框需要显示价格列表（在文本中，带有整数后端值）。

所有这些组合框都使用相同的数据源（A List＆lt;＆gt;类型为TSPrice，ValueMember设置为Price，DisplayMember设置为Description）。

我的问题是这样的...每当我从其中一个下拉列表中选择一个价格选项时，它们都会更改为相同的值...这是否与它们绑定到同一个数据源有关？

以下是我绑定他们的方式：

var priceList = new List<TSPrice>
                    {
                        new TSPrice(0, ""),
                        new TSPrice(0, "Half Day"),
                        new TSPrice(0, "Full Day"),
                        new TSPrice(0, "1 + Half"),
                        new TSPrice(0, "2 Days"),
                        new TSPrice(0, "Formal Quote Required")
                    };

objInsuredPrice.DataSource = priceList;
objTPPrice.DataSource = priceList;
objProvSum.DataSource = priceList;

objInsuredPrice.ValueMember = "Price";
objTPPrice.ValueMember = "Price";
objProvSum.ValueMember = "Price";

objInsuredPrice.DisplayMember = "Description";
objTPPrice.DisplayMember = "Description";
objProvSum.DisplayMember = "Description";

objInsuredPrice.SelectedIndex = 0;
objTPPrice.SelectedIndex = 0;
objProvSum.SelectedIndex = 0;

//objInsuredPrice.DataSource      = objTPPrice.DataSource     = objProvSum.DataSource     = priceList;
//objInsuredPrice.ValueMember     = objTPPrice.ValueMember    = objProvSum.ValueMember    = "Price";
//objInsuredPrice.DisplayMember   = objTPPrice.DisplayMember  = objProvSum.DisplayMember  = "Description";
//objInsuredPrice.SelectedIndex   = objTPPrice.SelectedIndex  = objProvSum.SelectedIndex  = 0;

编辑：问题是他们都被Saurabh所确认的绑定到同一个DataSource。这就是我解决它的方法。

var priceList = new List<TSPrice>
                    {
                        new TSPrice(0, ""),
                        new TSPrice(1, "Half Day"),
                        new TSPrice(2, "Full Day"),
                        new TSPrice(3, "1 + Half"),
                        new TSPrice(4, "2 Days"),
                        new TSPrice(5, "Formal Quote Required")
                    };

var insuredList = new TSPrice[5];
var TPList = new TSPrice[5];
var provList = new TSPrice[5];

priceList.CopyTo(insuredList);
priceList.CopyTo(TPList);
priceList.CopyTo(provList);

objInsuredPrice.DataSource = insuredList;
objTPPrice.DataSource = TPList;
objProvSum.DataSource = provList;

objInsuredPrice.ValueMember     = objTPPrice.ValueMember    = objProvSum.ValueMember    = "Price";
objInsuredPrice.DisplayMember   = objTPPrice.DisplayMember  = objProvSum.DisplayMember  = "Description";
objInsuredPrice.SelectedIndex   = objTPPrice.SelectedIndex  = objProvSum.SelectedIndex  = 0;

Answer 1

可能你也可以尝试这个解决方案，只需为第二个组合框分配一个新的Context：

                combobox1.DataSource = results;
                combobox1.DisplayMember = "DisplayValue";
                combobox1.ValueMember = "Value";

                combobox2.BindingContext = new BindingContext();   //create a new context
                combobox2.DataSource = results;
                combobox2.DisplayMember = "DisplayValue";
                combobox2.ValueMember = "Value";

谢谢

Answer 2

我不明白为什么这应该这么难......你只需将它们链接到同一数据源的克隆......就可以解决问题。您需要做的就是

objInsuredPrice.DataSource = new List<TSPrice>(priceList);
objTPPrice.DataSource = new List<TSPrice>(priceList);
objProvSum.DataSource = new List<TSPrice>(priceList);

顺便说一句，这正是VVS的代码所做的。

仍然，奇怪的行为......只是是一个错误，imo。

Answer 3

我知道你没有要求它，但我建议你稍微重构一下你的最终代码： - ）

private List<TSPrice> GetPriceList()
{
  return new List<TSPrice>
             {
               new TSPrice(0, ""),
               new TSPrice(0, "Half Day"),
               new TSPrice(0, "Full Day"),
               new TSPrice(0, "1 + Half"),
               new TSPrice(0, "2 Days"),
               new TSPrice(0, "Formal Quote Required")
             };
}

private void BindPriceList(ComboBox comboBox, List<TSPrice> priceList)
{
  comboBox.DataSource = priceList();
  comboBox.ValueMember = "Price";
  comboBox.DisplayMember = "Description";
  comboBox.SelectedIndex = 0;
}    

BindPriceList(objInsuredPrice, GetPriceList());
BindPriceList(objTPPrice, GetPriceList());
BindPriceList(objProvSum, GetPriceList());

Answer 4

是的，绝对你是正确的，因为你绑定到同一个源，所以选择一个将应用于其余的combox

为克服这个问题，你需要在slectedindex更改事件中手动删除其他组合框处理程序，然后设置所选索引，然后再添加处理程序以放入代码，如下所示

    ComboBox c1 = new ComboBox();
        ComboBox c2 = new ComboBox();

        c1.SelectedIndexChanged += new EventHandler(c1_SelectedIndexChanged);


        c2.SelectedIndexChanged += new EventHandler(c2_SelectedIndexChanged);

    void c2_SelectedIndexChanged(object sender, EventArgs e)
    {
        c1.SelectedIndexChanged -= c1_SelectedIndexChanged;
        c2.SelectedIndex = 2;
        c1.SelectedIndexChanged += c1_SelectedIndexChanged;

    }

    void c1_SelectedIndexChanged(object sender, EventArgs e)
    {
        c2.SelectedIndexChanged -= c2_SelectedIndexChanged;
        c1.SelectedIndex = 2;
        c2.SelectedIndexChanged += c2_SelectedIndexChanged;
    }

Answer 5

Beth Massi写了一篇文章，解释了此问题和正确的解决方案： https://blogs.msdn.microsoft.com/bethmassi/2007/09/19/binding-multiple-combo-boxes-to-the-same-data-source/

她还链接了一系列有关数据绑定的其他视频。

我已经阅读了之前的答案，可以确认的是，当我尝试使用它们时，没有一个起作用。

在组合框上创建新的BindingContext似乎破坏了它。我建议按照Beth的说明进行操作：进行全新的BindingSource设置。

Answer 6

这对我有用，我不需要复制来源。

List<string> days = GetDays();
List<string> months = GetMonths();
List<string> years = GetYears();

Son1DDLDay.DataSource = days;
Son1DDLDay.DataBind();
Son1DDLMonth.DataSource = months;
Son1DDLMonth.DataBind();
Son1DDLYear.DataSource = years;
Son1DDLYear.DataBind();

Son2DDLDay.DataSource = days;
Son2DDLDay.DataBind();
Son2DDLMonth.DataSource = months;
Son2DDLMonth.DataBind();
Son2DDLYear.DataSource = years;
Son2DDLYear.DataBind();

具有相同数据源的多个组合框（C＃）

6 个答案: