WPF 无法设置组合框的选定项目
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WPF Unable to set Selected Item of a Combo box
提问by Tvd
I have a non-bound Combobox and I want to set its value at run time. I tried a lot but cannot achieve it. Here's the code :
我有一个非绑定组合框，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>
In code, I am trying with :
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 & selectedValue has no impact. Why its not even able to find in Items ? How do I set it ?
SelectedItem 和 selectedValue 没有影响。为什么它甚至无法在 Items 中找到？我该如何设置？
Please help me, have several such non-bound and binded combos to set programmatically.
请帮助我，以编程方式设置几个这样的非绑定和绑定组合。
回答by McGarnagle
The issue is that your items are ComboBoxItems, not strings. So you have two options: one, use strings as the combo-box items (this allows you to set SelectedItem / SelectedValue = "meter" or "centimeter"):
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目（这允许你设置 SelectedItem / SelectedValue = "meter" or "centimeter"）：
<ComboBox xmlns:clr="clr-namespace:System;assembly=mscorlib">
<clr:String>meter</clr:String>
<clr:String>centimeter</clr:String>
</ComboBox>
ortwo, set the SelectedItemby searching for the appropriate ComboBoxItem:
或两个，SelectedItem通过搜索适当的来设置ComboBoxItem：
cboWellDiameter.SelectedItem = cboWellDiameter.Items.OfType<ComboBoxItem>()
.FirstOrDefault(item => item.Content as string == cosp.wellborediameterField_unit);
