我已根据下面提到的简短直接问题更新了我的问题： 我知道MVVM的基本知识，但我不知道它的实现。 问题： -
我认为这是因为执行不良或标准编码低。任何人都可以建议我做好实施。提前谢谢。
更新： - 我的a.xml
<Departments>
<Department>
<deptID>
1
</deptID>
<deptName>
Arts
</deptName>
<Sections>
<Section>
<sectionID>A</sectionID>
<sectionName>Political Science</sectionName>
<NoOfLecturers>5</NoOfLecturers>
</Section>
<Section>
<sectionID>B</sectionID>
<sectionName>Economics</sectionName>
<NoOfLecturers>3</NoOfLecturers>
</Section>
<Section>
<sectionID>C</sectionID>
<sectionName>Social Studies</sectionName>
<NoOfLecturers>7</NoOfLecturers>
</Section>
<Section>
<sectionID>D</sectionID>
<sectionName>History</sectionName>
<NoOfLecturers>5</NoOfLecturers>
</Section>
<Section>
<sectionID>E</sectionID>
<sectionName>Geography</sectionName>
<NoOfLecturers>2</NoOfLecturers>
</Section>
</Sections>
</Department>
<Department>
<deptID>
2
</deptID>
<deptName>
Sciences
</deptName>
<Sections>
<Section>
<sectionID>A</sectionID>
<sectionName>Physics</sectionName>
<NoOfLecturers>10</NoOfLecturers>
</Section>
<Section>
<sectionID>B</sectionID>
<sectionName>Mathematics</sectionName>
<NoOfLecturers>2</NoOfLecturers>
</Section>
<Section>
<sectionID>C</sectionID>
<sectionName>Chemistry</sectionName>
<NoOfLecturers>6</NoOfLecturers>
</Section>
<Section>
<sectionID>D</sectionID>
<sectionName>Botany</sectionName>
<NoOfLecturers>5</NoOfLecturers>
</Section>
<Section>
<sectionID>E</sectionID>
<sectionName>Zeology</sectionName>
<NoOfLecturers>4</NoOfLecturers>
</Section>
</Sections>
</Department>
<Department>
<deptID>
3
</deptID>
<deptName>
Commerce
</deptName>
<Sections>
<Section>
<sectionID>A</sectionID>
<sectionName>Accounting</sectionName>
<NoOfLecturers>3</NoOfLecturers>
</Section>
<Section>
<sectionID>B</sectionID>
<sectionName>Marketing</sectionName>
<NoOfLecturers>2</NoOfLecturers>
</Section>
<Section>
<sectionID>C</sectionID>
<sectionName>Human Resources</sectionName>
<NoOfLecturers>5</NoOfLecturers>
</Section>
<Section>
<sectionID>D</sectionID>
<sectionName>Finance</sectionName>
<NoOfLecturers>5</NoOfLecturers>
</Section>
</Sections>
</Department>
<Department>
<deptID>
4
</deptID>
<deptName>
Library
</deptName>
<Sections>
<Section>
<sectionID>A</sectionID>
<sectionName>Incharge</sectionName>
<NoOfLecturers>3</NoOfLecturers>
</Section>
<Section>
<sectionID>B</sectionID>
<sectionName>Clerk</sectionName>
<NoOfLecturers>3</NoOfLecturers>
</Section>
</Sections>
</Department>
</Departments>
我的WCFService.cs类（Service1.svc.cs）
// NOTE: You can use the "Rename" command on the "Refactor" menu to change the class name "Service1" in code, svc and config file together.
public class Service1 : IService1
{
XmlDocument doc;
string xmlPath = @"D:\WcfService1\WcfService1\Resources\a.xml";
public Dictionary<string, string> GetDeptIDName()
{
try
{
if (!File.Exists(xmlPath))
{
return null;
}
else
{
Dictionary<string, string> depIDName = new Dictionary<string, string>();
doc = new XmlDocument();
doc.Load(xmlPath);
XmlNodeList nl = doc.GetElementsByTagName("Department");
foreach (XmlNode node in nl)
{
string id = (node.FirstChild.InnerXml).Replace("\r", "").Replace("\n", "").Replace("\t", "");
string name = (node.FirstChild.NextSibling.InnerXml).Replace("\r", "").Replace("\n", "").Replace("\t", "");
depIDName.Add(id, name);
}
return depIDName;
}
}
catch (Exception)
{
return null;
}
}
public List<string> GetSectionsList(string deptName)
{
try
{
if (!File.Exists(xmlPath))
{
return null;
}
else
{
List<string> lstSectionList = new List<string>();
doc = new XmlDocument();
doc.Load(xmlPath);
XmlNodeList nl = doc.GetElementsByTagName("Department");
foreach (XmlNode node in nl)
{
string name = (node.FirstChild.NextSibling.InnerXml).Replace("\r", "").Replace("\n", "").Replace("\t", "");
if (name == deptName)
{
UpdateSectionsList(ref lstSectionList, node.LastChild);
}
}
return lstSectionList;
}
}
catch (Exception)
{
return null;
}
}
private void UpdateSectionsList(ref List<string> lstSectionList,
XmlNode xmlNode)
{
XmlNodeList nl = xmlNode.ChildNodes;
foreach (XmlNode xNode in nl)
{
foreach (XmlNode sectionNode in (XmlNodeList)xNode.ChildNodes)
{
if ("sectionID" == sectionNode.Name)
{
lstSectionList.Add(sectionNode.InnerXml);
}
}
}
}
/// <summary>
/// Get all the sections detail.
/// </summary>
/// <param name="deptName"></param>
/// <param name="sectionID"></param>
/// <returns></returns>
public CompositeType GetSectionDetail(string deptName,
string sectionID)
{
try
{
if (!File.Exists(xmlPath))
{
return null;
}
else
{
CompositeType compositeObj = new CompositeType();
doc = new XmlDocument();
doc.Load(xmlPath);
XmlNodeList nl = doc.GetElementsByTagName("Department");
foreach (XmlNode node in nl)
{
string name = (node.FirstChild.NextSibling.InnerXml).
Replace("\r", "").
Replace("\n", "").
Replace("\t", "");
if (name == deptName)
{
UpdateSectionDetail(out compositeObj,
GetSectionNodes(node.LastChild,
sectionID));
}
}
return compositeObj;
}
}
catch (Exception)
{
return null;
}
}
private void UpdateSectionDetail(out CompositeType compositeObj,
XmlNode xmlNode)
{
compositeObj =
new CompositeType();
compositeObj.SectionID =
xmlNode.FirstChild.InnerXml;
compositeObj.SectionName =
xmlNode.LastChild.PreviousSibling.InnerXml;
compositeObj.SectionLecturers =
xmlNode.LastChild.InnerXml;
}
private XmlNode GetSectionNodes(XmlNode xmlNode,
string sectionID)
{
try
{
XmlNodeList nl = xmlNode.ChildNodes;
XmlNode returnNode = xmlNode;
foreach (XmlNode xNode in nl)
foreach (XmlNode sectionNode in (XmlNodeList)xNode.ChildNodes)
if (("sectionID" == sectionNode.Name)
&&
(sectionNode.InnerXml == sectionID))
{
returnNode = xNode;
}
return returnNode;
}
catch(Exception)
{
return null;
}
}
}
IService1.cs接口
// NOTE: You can use the "Rename" command on the "Refactor" menu to change the interface name "IService1" in both code and config file together.
[ServiceContract]
public interface IService1
{
[OperationContract]
Dictionary<string, string> GetDeptIDName();
[OperationContract]
List<string> GetSectionsList(string deptName);
[OperationContract]
CompositeType GetSectionDetail(string deptName, string sectionID);
// TODO: Add your service operations here
}
// Use a data contract as illustrated in the sample below to add composite types to service operations.
[DataContract]
public class CompositeType
{
string sectionID = string.Empty, sectionName = string.Empty, NoOfLectures = string.Empty;
[DataMember]
public string SectionID
{
get
{
return sectionID;
}
set
{
sectionID = value;
}
}
[DataMember]
public string SectionName
{
get
{
return sectionName;
}
set
{
sectionName = value;
}
}
[DataMember]
public string SectionLecturers
{
get
{
return NoOfLectures;
}
set
{
NoOfLectures = value;
}
}
}
MainPage.xaml.cs类
public partial class MainPage : UserControl
{
Service1Client serviceClient = new Service1Client();
public MainPage()
{
InitializeComponent();
}
private void UserControl_Loaded(object sender, RoutedEventArgs e)
{
serviceClient.GetDeptIDNameCompleted += new EventHandler<GetDeptIDNameCompletedEventArgs>(serviceClient_GetDeptIDNameCompleted);
serviceClient.GetDeptIDNameAsync();
}
void serviceClient_GetDeptIDNameCompleted(object sender, GetDeptIDNameCompletedEventArgs e)
{
cbDeptName.ItemsSource = e.Result;
cbDeptName.SelectedItem = cbDeptName.Items[0];
}
private void cbDeptName_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
//Remove square brackets from the List box item.
string lstBoxItem = Regex.Replace(cbDeptName.SelectedValue.ToString(),
@"[\[\]\s]",
string.Empty);
//Split the list box item into two parts by considering the (,)
//to separate the DICOM ID and Patient name.
string[] strItems = (lstBoxItem).Split(Convert.ToChar(","));
serviceClient.GetSectionsListCompleted += new EventHandler<GetSectionsListCompletedEventArgs>(serviceClient_GetSectionsListCompleted);
serviceClient.GetSectionsListAsync(strItems[1]);
}
void serviceClient_GetSectionsListCompleted(object sender, GetSectionsListCompletedEventArgs e)
{
cbDeptSections.ItemsSource = e.Result;
cbDeptSections.SelectedItem = cbDeptSections.Items[0];
//serviceClient.GetSectionDetailCompleted += new EventHandler<GetSectionDetailCompletedEventArgs>(serviceClient_GetSectionDetailCompleted);
//serviceClient.GetSectionDetailAsync(strItems[1], cbDeptSections.SelectedItem.ToString());
}
private void cbDeptSections_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (null == cbDeptSections.SelectedItem)
return;
lbSectionDetail.Items.Clear();
//Remove square brackets from the List box item.
string lstBoxItem = Regex.Replace(cbDeptName.SelectedValue.ToString(),
@"[\[\]\s]",
string.Empty);
//Split the list box item into two parts by considering the (,)
//to separate the DICOM ID and Patient name.
string[] strItems = (lstBoxItem).Split(Convert.ToChar(","));
serviceClient.GetSectionDetailCompleted += new EventHandler<GetSectionDetailCompletedEventArgs>(serviceClient_GetSectionDetailCompleted);
serviceClient.GetSectionDetailAsync(strItems[1], cbDeptSections.SelectedItem.ToString());
}
void serviceClient_GetSectionDetailCompleted(object sender, GetSectionDetailCompletedEventArgs e)
{
CompositeType compositeObj = e.Result;
//lbSectionDetail.Items.Clear();
lbSectionDetail.Items.Add(compositeObj.SectionID);
lbSectionDetail.Items.Add(compositeObj.SectionName);
lbSectionDetail.Items.Add(compositeObj.SectionLecturers);
}
}
MainPage.xaml中
<StackPanel>
<StackPanel
x:Name ="LayoutRoot"
Background ="White"
Orientation ="Horizontal"
>
<ComboBox
x:Name ="cbDeptID"
MinWidth ="50"
HorizontalContentAlignment ="Center"
DisplayMemberPath ="Key"
SelectedValue ="{Binding ElementName=cbDeptName, Path=SelectedValue, Mode=TwoWay}"
/>
<ComboBox
x:Name ="cbDeptName"
MinWidth ="50"
DisplayMemberPath ="Value"
SelectionChanged ="cbDeptName_SelectionChanged"
/>
<ComboBox
x:Name ="cbDeptSections"
MinWidth ="100"
SelectionChanged ="cbDeptSections_SelectionChanged"
/>
</StackPanel>
<ListBox
x:Name ="lbSectionDetail"
ScrollViewer.HorizontalScrollBarVisibility ="Auto"
ScrollViewer.VerticalScrollBarVisibility ="Auto"
/>
clientaccesspolicy.xml
<?xml version="1.0" encoding="utf-8" ?>
<access-policy>
<cross-domain-access>
<policy>
<allow-from http-request-headers="SOAPAction">
<domain uri="*"/>
</allow-from>
<grant-to>
<resource path="/" include-subpaths="true"/>
</grant-to>
</policy>
</cross-domain-access>
</access-policy>
答案 0 :(得分：3)
我认为多次通话的罪魁祸首可能是
serviceClient.GetSectionDetailCompleted += new EventHandler<GetSectionDetailCompletedEventArgs>(serviceClient_GetSectionDetailCompleted);
在我看来，您正在多次注册完成事件，但从未注销它。您调用cbDeptName_SelectionChanged和cbDeptName_SelectionChanged的次数越多，创建的事件处理程序就越多。当您的服务返回一个响应时，它们都会被调用。
编辑：
第一次加载应用程序时调用这些方法的原因是，当绑定组合框控件时，它们会自动将所选项目更改为列表中的第一项，从而调用SelectionChanged事件。
编辑2：
为了避免对同一事件进行多次调用，您应该在Loaded事件中注册仅该事件，就像执行serviceClient.GetDeptIDNameCompleted
您的加载事件应如下所示：
private void UserControl_Loaded(object sender, RoutedEventArgs e)
{
// Put these here instead of where they are now
serviceClient.GetSectionsListCompleted += new EventHandler<GetSectionsListCompletedEventArgs>(serviceClient_GetSectionsListCompleted);
serviceClient.GetSectionDetailCompleted += new EventHandler<GetSectionDetailCompletedEventArgs>(serviceClient_GetSectionDetailCompleted);
serviceClient.GetDeptIDNameCompleted += new EventHandler<GetDeptIDNameCompletedEventArgs>(serviceClient_GetDeptIDNameCompleted);
serviceClient.GetDeptIDNameAsync();
}
不要忘记从代码中的这些行中删除这些行。