Question

我有一个C＃Windows窗体应用程序，并且在窗体加载方法中，我加载了一些组合框。对于其中之一，MeasureType，它显示的是ValueMember字段，这只是一个无意义的ID。我想要MeasureType描述（MeasureType1）。我注意到，如果刷新或调用函数以两次（背对背）加载组合框，则它将起作用并显示说明字段。我尝试按照下面的代码中分配属性的顺序设置DataSource的第一个和最后一个。所有其他组合框均按预期工作。有人知道我在做什么错吗？

    private void MeasureForm_Load(object sender, EventArgs e)
    {
        LoadForm();
        LoadForm();  //if I call twice, it shows DisplayMember field
    }

    private void LoadForm()
    {
        measLoader = new MeasureData();

        cbCurrentMeasures.DataSource = measLoader.GetMeasuresWithEmpty();
        cbCurrentMeasures.DisplayMember = "MeasureName";
        cbCurrentMeasures.ValueMember = "MeasureID";           

        //*** THIS ONE IS NOT SHOWING DISPLAYMEMBER ***  
        cbTypes.DataSource = measLoader.GetMeasureTypes();
        cbTypes.DisplayMember = "MeasureType1";
        cbTypes.ValueMember = "MeasureTypeID";


        cbMethods.DataSource = measLoader.GetWebServiceMethodsWithEmpty();
        cbMethods.DisplayMember = "MethodName";
        cbMethods.ValueMember = "WebServiceMethodID";

        cbProperties.DataSource = measLoader.GetClassPropertiesWithEmpty();
        cbProperties.DisplayMember = "DisplayField";
        cbProperties.ValueMember = "PropertyID";

        chklistItems.DataSource = measLoader.GetItems();
        ((ListBox)chklistItems).DisplayMember = "ItemName";
        ((ListBox)chklistItems).ValueMember = "ItemID";    
    }

    private void cbTypes_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (cbTypes.Text.Contains("QI"))
        {
            cbProperties.Enabled = false;
            cbProperties.SelectedIndex = 0;
        }
        else
        {
            cbProperties.Enabled = true;
        }
    }

使用linq-to-sql的MeasurementData类：

 public List<MeasureType> GetMeasureTypes()
 {
     return db.MeasureTypes.ToList<MeasureType>();
 }

Answer 1

由于cbMeasureTypes上的事件处理程序试图在没有任何数据之前设置cbProperties的SelectedIndex，因此将cbProperties的加载移到了cbMeasureTypes之前。

加载后如何获取组合框以显示DisplayMember？

1 个答案: