wpf datagrid 的单元格内容超出列宽度

<Window x:Class="WpfApplication2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<DataGrid Name="grid1" AutoGenerateColumns="False">
<DataGrid.Columns>
<!--自定义列-->
<DataGridTemplateColumn Header="姓名" Width="30" MaxWidth="100">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<!--设置当单元格内容超过最大长度时，显示...-->
<TextBlock Text="{Binding Name}" TextTrimming="WordEllipsis"/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.CellStyle>
<Style>
<!--加tooltip，显示单元格内容-->
<Setter Property="ToolTipService.ToolTip" Value="{Binding Name}"/>
</Style>
</DataGridTemplateColumn.CellStyle>
</DataGridTemplateColumn>
<DataGridTextColumn Header="年龄" Binding="{Binding Age}" Width="50"/>
</DataGrid.Columns>
</DataGrid>
</Grid>