以编程方式注册自定义ASP.NET ExpressionBuilder
是否可以在应用程序启动期间以编程方式注册自定义的以编程方式注册自定义ASP.NET ExpressionBuilder,asp.net,webforms,web-config,expressionbuilder,Asp.net,Webforms,Web Config,Expressionbuilder,是否可以在应用程序启动期间以编程方式注册自定义的ExpressionBuilder类 等价的web.config声明显然是: <system.web> <compilation> <expressionBuilders> <add expressionPrefix="MyPrefix" type="MyNamespace.MyExpressionBuilder"> </expressionB
ExpressionBuilder
类
等价的web.config
声明显然是:
<system.web>
<compilation>
<expressionBuilders>
<add expressionPrefix="MyPrefix" type="MyNamespace.MyExpressionBuilder">
</expressionBuilders>
</compilation>
</system.web>
如何在自定义HTTP模块Init()
、应用程序启动或BeginRequest
期间动态注册此文件,而不修改web.config
?我找到了
其中包括以下示例
class UsingExpressionBuildCollection {
static void Main(string[] args)
{
try
{
// Set the path of the config file.
string configPath = "";
// Get the Web application configuration object.
Configuration config =
WebConfigurationManager.OpenWebConfiguration(configPath);
// Get the section related object.
CompilationSection configSection =
(CompilationSection)config.GetSection("system.web/compilation");
// Display title and info.
Console.WriteLine("ASP.NET Configuration Info");
Console.WriteLine();
// Display Config details.
Console.WriteLine("File Path: {0}",
config.FilePath);
Console.WriteLine("Section Path: {0}",
configSection.SectionInformation.Name);
// Create a new ExpressionBuilder reference.
ExpressionBuilder myExpressionBuilder =
new ExpressionBuilder("myCustomExpression", "MyCustomExpressionBuilder");
// Add an ExpressionBuilder to the configuration.
configSection.ExpressionBuilders.Add(myExpressionBuilder);
// Add an ExpressionBuilder to the configuration.
ExpressionBuilder myExpressionBuilder2 =
new ExpressionBuilder("myCustomExpression2", "MyCustomExpressionBuilder2");
configSection.ExpressionBuilders.Add(myExpressionBuilder2);
// Display the ExpressionBuilder count.
Console.WriteLine("ExpressionBuilder Count: {0}",
configSection.ExpressionBuilders.Count);
// Display the ExpressionBuildersCollection details.
int i = 1;
int j = 1;
foreach (ExpressionBuilder expressionBuilder in configSection.ExpressionBuilders)
{
Console.WriteLine();
Console.WriteLine("ExpressionBuilder {0} Details:", i);
Console.WriteLine("Type: {0}", expressionBuilder.ElementInformation.Type);
Console.WriteLine("Source: {0}", expressionBuilder.ElementInformation.Source);
Console.WriteLine("LineNumber: {0}", expressionBuilder.ElementInformation.LineNumber);
Console.WriteLine("Properties Count: {0}", expressionBuilder.ElementInformation.Properties.Count);
j = 1;
foreach (PropertyInformation propertyItem in expressionBuilder.ElementInformation.Properties)
{
Console.WriteLine("Property {0} Name: {1}", j, propertyItem.Name);
Console.WriteLine("Property {0} Value: {1}", j, propertyItem.Value);
++j;
}
++i;
}
// Remove an ExpressionBuilder.
configSection.ExpressionBuilders.RemoveAt
(configSection.ExpressionBuilders.Count-1);
// Remove an ExpressionBuilder.
configSection.ExpressionBuilders.Remove("myCustomExpression");
// Update if not locked.
if (!configSection.SectionInformation.IsLocked)
{
config.Save();
Console.WriteLine("** Configuration updated.");
}
else
{
Console.WriteLine("** Could not update, section is locked.");
}
}
catch (Exception e)
{
// Unknown error.
Console.WriteLine(e.ToString());
}
// Display and wait.
Console.ReadLine();
}
}
}
重要的是
Configuration config =
WebConfigurationManager.OpenWebConfiguration(configPath);
// Get the section related object.
CompilationSection configSection =
(CompilationSection)config.GetSection("system.web/compilation");
//...
// Create a new ExpressionBuilder reference.
var myExpressionBuilder = new ExpressionBuilder(
expressionPrefix: "MyPrefix",
theType: "MyNamespace.MyExpressionBuilder"
);
// Add an ExpressionBuilder to the configuration.
configSection.ExpressionBuilders.Add(myExpressionBuilder);
//...
// Update if not locked.
if (!configSection.SectionInformation.IsLocked) {
config.Save();
}
上述内容与此配置示例相当
<system.web>
<compilation>
<expressionBuilders>
<add expressionPrefix="MyPrefix" type="MyNamespace.MyExpressionBuilder">
</expressionBuilders>
</compilation>
</system.web>
我还没有找到任何其他的可扩展性点,除了到目前为止所展示的能够注入定制构建程序programmaticaly的扩展点之外
同样考虑到System.Web的封闭源代码特性,我怀疑将来任何时候都会有。正确,但是,我担心config.Save()
实际上会试图写回物理Web.config文件并进行更新,因为这不是我想要的。是这样做的吗?@qJake yes save可用于更新或创建新的配置文件。@qJake在查看.net引用源之后,页面解析器似乎直接从配置中通过内部命令加载表达式生成器。我找不到任何其他的扩展点,除了到目前为止已经显示的可以注入构建器的扩展点。谢谢你的信息。我们必须评估是否要以编程方式或通过其他方式实际更新web.config,但最好了解API的工作原理。谢谢