我的 InitializeComponent();
行返回错误时,我将以下行添加到我的comboboxItem选择事件:
namespace NewProject
{
public partial class Page1 : Page
{
public Page1
{
InitializeComponent();
}
private void ComboBoxItem_Selected_1(object sender, RoutedEventArgs e) //same for ComboBoxItem_Selected_2,3
{
TextBlock_ComboBoxes.Text = ("Combo Box Number: 1");
}
}
}
我试图根据选择的组合构象来更改文本块的文本。
XAML代码:
<ComboBox FontFamily="Arial" Grid.ColumnSpan="2">
<ComboBoxItem Content="Combo Box Number 1" IsSelected="True" Selected="ComboBoxItem_Selected_1"/>
<ComboBoxItem Content="Combo Box Number 2" Selected="ComboBoxItem_Selected_2"/>
<ComboBoxItem Content="Combo Box Number 3" Selected="ComboBoxItem_Selected_3"/>
</ComboBox>
<TextBlock x:Name="TextBlock_ComboBoxes" Text="Combo Box Number: 1"/>
此XAML代码包含在窗口内的帧中的页面中。这些是页面属性:
<Page x:Class="NewProject.Page1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="600"
Title="Page 1">
在InitializeComponent
期间,可以在初始化TextBlock_ComboBoxes
字段之前触发选择变为事件。您应该检查字段是否为 null
:
private void ComboBoxItem_Selected_1(object sender, RoutedEventArgs e)
{
if (TextBlock_ComboBoxes != null)
{
TextBlock_ComboBoxes.Text = ("Combo Box Number: 1");
}
}