在DataGrid中实现Button Command绑定

在DataGrid中实现Button Command绑定

Command="{Binding editCommand}" 会默认查找UserList中对象的属性，而你的UserList中对象应该不包括editCommand属性;
可以尝试:
Command="{Binding DataContext.editCommand,RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Windows}}}"

<DataGrid ItemsSource="{Binding UserList}" Name="PregnantDataGrid"
          IsReadOnly="True"
          AutoGenerateColumns="False" HeadersVisibility="All" >
    <DataGrid.Columns>
        <DataGridTextColumn Width="150" Header="姓名"  Binding="{Binding realName}" />
        <DataGridTextColumn Width="100" Header="手机号" Binding="{Binding phoneNo}" />
        <DataGridTemplateColumn Width="60" CanUserResize="False" Header="操作">
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <DockPanel HorizontalAlignment="Left" Margin="5,0,0,0">
                        <Button Content="编辑" Margin="5" Width="80"
                        Command="{Binding DataContext.editCommand,RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type DataGrid}}}" CommandParameter="{Binding}" />
                    </DockPanel>
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
    </DataGrid.Columns>
</DataGrid>

public class VmUser : ViewModelBase
{
    public VmUser()
    {
    EditCommand = new RelayCommand(EditCommandMethod, CanEditExecute);
    }

    public RelayCommand EditCommandMethod { get; set; }

    private void EditCommandMethod(object param)
    {
        var obj = param as UserInfo;
        MessageBox.Alert(obj.UserName);
    }

    private bool CanEditExecute(object obj)
    {
        return true;
    }
}