将组合框选定项与列表项进行比较 [英] Compare Combo box selected item with list items

问题描述

大家好

  Dim  list  As  新列表（  整数）
  Dim  cmd1 作为 新 SqlCommand（ 从SuppReport选择月（FromDate），con） 
 con.Open（）
 
  Dim  dr  As  SqlDataReader = cmd1.ExecuteReader（）
 
  while  dr.Read（）
 list.Add（dr（ 0 ））
 结束   
 
 TextBlock12.Text = 字符串 .Join（ ，，list.ToArray（））
 

i使用此代码，我可以获取此列表中的所有月份数。

现在我必须将每个项目与组合框选择的月份数进行比较，并在数据网格中显示记录。

请告诉我怎么做..

解决方案

你好



你是期待在ComboBox中显示选定的月份编号，但ComboBox不支持多项选择。



让我们从显示月份列表开始：

 <   ListBox     SelectionMode   = 多个    DataContext   =  1,3,5   >  
 <   ListBox.Items  >  
 <   ListBoxItem     IsSelected   =  {Binding 
 Mode = OneWay，
 Converter = {StaticResource csvc}，ConverterParameter = 1} >  1月<   / ListBoxItem  >  
 <   ListBoxItem     IsSelected   =  {Binding 
 Mode = OneWay，
 Converter = {StaticResource csvc}，ConverterParameter = 2} > ; 二月<   / ListBoxItem  >  
 <   ListBoxItem     IsSelected   =  {Binding 
 Mode = OneWay，
 Converter = {StaticResource csvc}，ConverterParameter = 3} >  March <   / ListBoxItem  >  
 <   ListBoxItem     IsSelected   =  {Binding 
 Mode = OneWay，
 Converter = {StaticResource csvc}，ConverterParameter = 4} > 四月<   / ListBoxItem  >  
 <  < span class =code-leadattribute> ListBoxItem     IsSelected   =  {Binding 
 Mode = OneWay，
 Converter = {StaticResource csvc}，ConverterParameter = 5} < span class =code-keyword>> 可以<   / ListBoxItem  >  
 <   / ListBox.Items  >  
 <   / ListBox  >  

csvc是一个转换你的csv的转换器（在这种情况下为1,3,5）并且如果参数在其中则返回true，它的源代码如下

 [ValueConversion （ typeof （ string ）， typeof （  bool ））] 
  public   class  CsvContainsConverter：IValueConverter 
 {
  public   object 转换（ object   value ，输入targetType， object 参数，System.Globalization .CultureInfo文化）
 {
  return （（ string ） value ）。拆分（' ，'）。包含（（ string < /跨度>）参数）; 
} 
 
  public   object  ConvertBack（ object   value ，键入targetType， object 参数，System.Globalization。 CultureInfo culture）
 {
  throw   new  NotImplementedException（）; 
} 
} 

因此，您会看到一个列表视图，显示您选择的月份为IsSelected，那么您需要下载类似DropDown的控件，

你可以使用我的DropDown -

DropDown.cs （控制）

DropDown.xaml （主题）

完整的库



参考控件后，您可以使用下拉列表。

（xmlns ：bc =http://www.quickzip.org/BaseControls

xmlns：conv =clr-namespace：QuickZip.Converters; assembly = FileExplorer3）

 <   bc：DropDown  < span class =code-at致敬>   DataContext   =  1， 3,5 >  
 <   bc：DropDown.Resources  >  
 <  < span class =code-leadattribute> conv：CsvContainsConverter     x：Key   =  csvc    /  >  
 <   / bc：DropDown.Resources  >  
 <   bc：DropDown.Header  >  
 <   TextBlock    文本  =  {Binding}    /  >  
 <   / bc：DropDown.Header  >  
 <   bc：DropDown.Content  >  
 ...列表框这里
 <   / bc：DropDown.Content  >  
 <   / bc：DropDown  >  

结果看起来像这一个：

截图

Hi all

Dim list As New List(Of Integer)
       Dim cmd1 As New SqlCommand("Select Month(FromDate) from SuppReport", con)
       con.Open()

       Dim dr As SqlDataReader = cmd1.ExecuteReader()

       While dr.Read()
           list.Add(dr(0))
       End While

       TextBlock12.Text = String.Join(",", list.ToArray())

i used this code i am able to fetch all the month number in this list.
Now i have to compare each item with combo box selected month number and display the records in a datagrid.
Please tell me how to do this..

解决方案

Hello

Are you looking to show selected month number in a ComboBox, but ComboBox does not support multiple selection.

Lets start from display a list of month :

<ListBox SelectionMode="Multiple" DataContext="1,3,5" >
    <ListBox.Items>
        <ListBoxItem IsSelected="{Binding 
        Mode=OneWay,
        Converter={StaticResource csvc}, ConverterParameter=1}">January</ListBoxItem>
        <ListBoxItem IsSelected="{Binding 
        Mode=OneWay,
        Converter={StaticResource csvc}, ConverterParameter=2}">Febrary</ListBoxItem>
        <ListBoxItem IsSelected="{Binding 
        Mode=OneWay,
        Converter={StaticResource csvc}, ConverterParameter=3}">March</ListBoxItem>
        <ListBoxItem IsSelected="{Binding 
        Mode=OneWay,
        Converter={StaticResource csvc}, ConverterParameter=4}">April</ListBoxItem>
        <ListBoxItem IsSelected="{Binding 
        Mode=OneWay,
        Converter={StaticResource csvc}, ConverterParameter=5}">May</ListBoxItem>
    </ListBox.Items>
</ListBox>

csvc is a Converter that convert your csv (1,3,5 in this case) and return true if Parameter is in it, it's source code like this

[ValueConversion(typeof(string), typeof(bool))]
public class CsvContainsConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return ((string)value).Split(',').Contains((string)parameter);
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

So you get a list view displaying your selected months as IsSelected, then you need to download a DropDown-like control,
you may use my DropDown -
DropDown.cs (control)
DropDown.xaml (theme)
Full library

After you reference the control, you can use the dropdown.
(xmlns:bc="http://www.quickzip.org/BaseControls"
xmlns:conv="clr-namespace:QuickZip.Converters;assembly=FileExplorer3")

<bc:DropDown DataContext="1,3,5">
  <bc:DropDown.Resources>
    <conv:CsvContainsConverter x:Key="csvc" />
  </bc:DropDown.Resources>
  <bc:DropDown.Header>
    <TextBlock Text="{Binding}" />
  </bc:DropDown.Header>
  <bc:DropDown.Content>
          ...ListBox here
  </bc:DropDown.Content>
</bc:DropDown>

The result is look like this one:
screenshot

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