【发布时间】：2023-01-30 20:15:36
【问题描述】：
我正在制作一个简单的 WPF 程序，用户基本上只需要使用 USB 条码扫描仪扫描条码，程序就会将数据直接发送到云 ERP。现在，该程序可以运行，但用户必须在扫描后手动单击文本框，清除数据并再次扫描。我只希望用户打开软件并继续使用他的条形码阅读器进行扫描，而不必手动擦除文本框数据。我怎样才能做到这一点？
<Window x:Class="ProductionScanner.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:viewModel="clr-namespace:ProductionScanner.MVVM.ViewModel"
xmlns:local="clr-namespace:ProductionScanner"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800"
Background="#181735" >
<Window.DataContext>
<viewModel:ReceiptViewModel />
</Window.DataContext>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="25" />
<RowDefinition/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Grid Background="#0F0F2D"
Grid.ColumnSpan="2">
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBlock Text="Foods"
Foreground="White"
Grid.Column="1"
VerticalAlignment="Center"
HorizontalAlignment="Left"
/>
<TextBlock Text="Records"
Foreground="White"
Grid.Column="2"
VerticalAlignment="Center"
HorizontalAlignment="Center"
/>
</Grid>
<StackPanel FocusManager.FocusedElement="{Binding ElementName=txtIniFocus}">
<TextBox x:Name="txtIniFocus" Margin="6" Text="{Binding Barcode, UpdateSourceTrigger=PropertyChanged}" HorizontalAlignment="Center" TextWrapping="Wrap" VerticalAlignment="Top" Width="150" Grid.Row="1" TextChanged="TextBox_TextChanged">
<TextBox.InputBindings>
<KeyBinding Key="Enter" Command="{Binding ReceiptCommand}" />
</TextBox.InputBindings>
</TextBox>
</StackPanel>
</Grid>
并且，ReceiptViewModel.cs：
using ProductionScanner.Cores;
using ProductionScanner.MVVM.Model;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml.Linq;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System.Windows;
using System.Windows.Controls.Primitives;
namespace ProductionScanner.MVVM.ViewModel
{
public class ReceiptViewModel: ObservableObject
{
private string _barcode;
public string Barcode
{
get { return _barcode; }
set { _barcode = value; OnPropertyChanged(); }
}
public RelayCommand ReceiptCommand { get; set; }
public ReceiptViewModel()
{
ReceiptCommand = new RelayCommand(x =>
{
receiptInventory();
});
}
private void receiptInventory()
{
if (Barcode.Length == 12)
{
var inventoryIDFrom = Barcode.Substring(0, 6);
var kgIntFrom = Barcode.Substring(6);
var kgDecimalFrom = kgIntFrom.Substring(0,kgIntFrom.Length-4) + "." + kgIntFrom.Substring(kgIntFrom.Length - 4, 3);
ERPRestService _erpRestService = new ERPRestService();
ReceiptItems receiptItems = new ReceiptItems();
receiptItems.InventoryID = inventoryIDFrom;
receiptItems.Qty = Convert.ToDecimal(kgDecimalFrom);
receiptItems.WarehouseID = "WH001";
receiptItems.LocationID = "L001";
receiptItems.LotSerialNbr = "";
receiptItems.ExpirationDate = DateTime.Now;
try
{
var jsonObj1 = new
{
Description = new
{
value = "Receipt"
},
Hold = new
{
value = false
},
Details = new[]
{
new {
InventoryID = new
{
value = receiptItems.InventoryID
},
Qty = new
{
value = receiptItems.Qty
},
WarehouseID = new
{
value = receiptItems.WarehouseID
},
Location = new
{
value = receiptItems.LocationID
}
}
}
};
string entityAsString = JsonConvert.SerializeObject(jsonObj1);
//string parameters1 = "$expand=Details";
var receipt = _erpRestService.Put("InventoryReceipt", null, entityAsString);
string refRelease = JObject.Parse(receipt)["ReferenceNbr"]["value"].ToString();
var release = new
{
entity = new
{
ReferenceNbr = new
{
value = refRelease
}
}
};
string jsonRelease = JsonConvert.SerializeObject(release);
jsonRelease = _erpRestService.Post("InventoryReceipt", "ReleaseInventoryReceipt", jsonRelease);
MessageBox.Show("Your AR Confirm has completed.", "Confirm", MessageBoxButton.OK, MessageBoxImage.Information);
}
catch (Exception ex)
{
throw (ex);
}
finally
{
_erpRestService.Dispose();
}
}
}
}
}
【问题讨论】：
-
你不能在消息框后面做
Barcode = string.Empty吗？或者我错过了什么？ -
@RyanThomas 我以前试过，没用:(
-
您在 TextBox 和属性之间的绑定是否确实正常工作？我注意到此框上还有一个 TextChanged 事件，它的作用是什么？
-
消息框将获得焦点。你应该失去那个。改为在文本块中显示您的消息。
-
由于您有 UpdateSourceTrigger=PropertyChanged，您可以检查文本框中是否有 12 个字符，如果有则打印您的收据。失去命令。我认为如果您将焦点保留在文本框中，然后将 Barcode 设置为 string.empty 将允许您再次扫描它。一旦失去焦点，您就不会将下一个代码扫描到其中。