WPF无法设置组合框的选定项

Question

我有一个非绑定的Combobox,我想在运行时设置它的值.我尝试了很多,但无法实现.这是代码:

<ComboBox  Background="#FFB7B39D" Grid.Row="1" Height="23" 
HorizontalAlignment="Right" Margin="0,26,136,0" 
Name="cboWellDiameter" VerticalAlignment="Top" Width="120">

     <ComboBoxItem Content="meter" IsSelected="True" />
         <ComboBoxItem Content="centimeter" />
</ComboBox>

在代码中,我正在尝试:

//VALUE of  sp.wellborediameterField_unit is centimeter
// Gives -1
int index = cboWellDiameter.Items.IndexOf(sp.wellborediameterField_unit);

Console.WriteLine("Index of well bore dia unit = " + index.ToString());  
cboWellDiameter.SelectedIndex = index;

// cboWellDiameter.SelectedItem = sp.wellborediameterField_unit;
// cboWellDiameter.SelectedValue = sp.wellborediameterField_unit;

SelectedItem和selectedValue没有任何影响.为什么它甚至无法在物品中找到？我该如何设置？

请帮助我,有几个这样的非绑定和绑定组合以编程方式设置.

Answer 1

问题是您的项目是ComboBoxItems,而不是字符串.所以你有两个选择:一,使用字符串作为组合框项(这允许你设置SelectedItem/SelectedValue ="米"或"厘米"):

<ComboBox xmlns:clr="clr-namespace:System;assembly=mscorlib">
     <clr:String>meter</clr:String>
     <clr:String>centimeter</clr:String>
</ComboBox>

或者两个,SelectedItem通过搜索适当的设置ComboBoxItem:

cboWellDiameter.SelectedItem = cboWellDiameter.Items.OfType<ComboBoxItem>()
    .FirstOrDefault(item => item.Content as string == cosp.wellborediameterField_unit);