[英]Tabcontrol in WPF C#
现在我正在使用tabcontrol来排列我的UI。 首先,我将按钮放在tabcontrol之外; 但是,当我将按钮放入tabcontrol时,它给出了消息, Object reference not set to an object instance
。 有人知道我为什么收到此消息吗?
已编辑
以下是我的xaml:
<Window x:Class="StudySystem.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="UI" Height="600" Width="811" mc:Ignorable="d" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:my="clr-namespace:StudySystem" Loaded="Window_Loaded">
<Grid Width="791">
<Grid.RowDefinitions>
<RowDefinition Height="129*" />
<RowDefinition Height="432*" />
</Grid.RowDefinitions>
<TabControl Margin="2,0,0,42">
<TabItem Header="Book Info" >
<Grid ShowGridLines="False">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="100" />
<ColumnDefinition Width="150" />
<ColumnDefinition Width="150" />
<ColumnDefinition Width="178*" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="22*" />
</Grid.RowDefinitions>
<TextBlock Text="Book Code:" Height="25" Margin="0,15,0,45"></TextBlock>
<TextBox Name="txtCode" Grid.Column="1" Margin="2,15,0,51"
Width="148"></TextBox>
<TextBlock Grid.Row="1" Text="Title:" Margin="0,1,0,33" Height="18"></TextBlock>
<TextBox Name="txtTitle" Grid.Row="1" Grid.Column="1" Margin="2,1,148,32" Grid.ColumnSpan="2"></TextBox>
<TextBlock Grid.Row="3" Text="Author:" Margin="0,5,0,33" Height="17"></TextBlock>
<TextBox Name="txtAuthor" Grid.Row="3" Grid.Column="1" Margin="0,6,0,30"></TextBox>
<Button Content="OK" Grid.Row="4" Grid.Column="1" Margin="0,1,0,37"></Button>
</Grid>
</TabItem>
</TabControl>
</Grid>
</Window>
我之前已经看过这一点,它的代码在创建表单之前引用了表单中的内容。 检查呼叫的顺序。
在Windows标记内,我添加了此代码,对我来说它可以正常工作...
<Grid Width="auto">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="432*" />
</Grid.RowDefinitions>
<TabControl Grid.Row="1">
<TabItem Header="Book Info" >
<Grid ShowGridLines="False">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="100" />
<ColumnDefinition Width="150" />
<ColumnDefinition Width="150" />
<ColumnDefinition Width="178*" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="22*" />
</Grid.RowDefinitions>
<TextBlock Text="Book Code:" Height="25" Margin="0,15,0,45"> </TextBlock>
<TextBox Name="txtCode" Grid.Column="1" Margin="2,15,0,51"
Width="148"></TextBox>
<TextBlock Grid.Row="1" Text="Title:" Margin="0,1,0,33" Height="18"></TextBlock>
<TextBox Name="txtTitle" Grid.Row="1" Grid.Column="1" Margin="2,1,148,32" Grid.ColumnSpan="2"></TextBox>
<TextBlock Grid.Row="3" Text="Author:" Margin="0,5,0,33" Height="17"></TextBlock>
<TextBox Name="txtAuthor" Grid.Row="3" Grid.Column="1" Margin="0,6,0,30"></TextBox>
<Button Content="OK" Grid.Row="4" Grid.Column="1" Margin="0,1,0,37"></Button>
</Grid>
</TabItem>
</TabControl>
</Grid>
您在window_loaded中提到的内容?
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