I tried something like this:
[NonSerialized]
private string _DecodeText;
public string DecodeText { get { return _DecodeText; } set { _DecodeText = value; } }
But it does not work. "DecodeText" is still in the serialized file. How can i prevent the property from serializing?
I Suspect you're using the XmlSerializer? If so use the [XmlIgnore] attribute instead.
This should be applied to the property instead of the backing field as the XmlSerializer serializes public fields and properties (whereas the BinaryFormatter uses refelction to get at the private fields - hence the marking of the private field with NonSerialized when using a BinaryFormatter).
I was able to use the following and not have the property serialized (.NET 4.0):
private string _DecodeText;
[System.Xml.Serialization.XmlIgnore]
public string DecodeText { get { return _DecodeText; } set { _DecodeText = value; } }
Updated Answer
The [NonSerialized] atttibute is on the variable not the property, but it cannot be on the attribute. So it is not going to help.
One way to prevent the property being serialized is to add a method
public bool ShouldSerializeDecodeText() {
return false;
}
and this (for the XmlSerializer at least) will prevent the property being serialized.
If you don't want to add lots of methods to the class just for serialization you might try inheriting from it and adding the methods to the derived class.
hth,
Alan.
I built on top of #John's answer and modified ef.tt template
to include [System.Xml.Serialization.XmlIgnore]
Here is the code
foreach (var navigationProperty in navigationProperties)
{
if (navigationProperty.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.Many)
{
#>
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
[System.Xml.Serialization.XmlIgnore]
<#
}
#>
<#=codeStringGenerator.NavigationProperty(navigationProperty)#>
<#
}
I think this code that will be help you all. With properties you declared and you want it to be serialized only. Then you should add a method return type as boolean and name method is ShouldSerialize as prefix with [NameProperty]. A scratch code as below and link reference to Newtonsoft for you:
public class DisplayFieldSetting
{
public bool ShouldSerializeHidden()
{
return false;
}
public bool ShouldSerializeKeepOriginialColumnName()
{
return false;
}
public string Hidden { get; set; }
public string KeepOriginialColumnName{ get; set; }
}
Related
I need to mark some properties as passwords so that they could be automatically screened. I found a standard attribute for that:
[PasswordPropertyText]
public string ThePassword { get; set; }
Following method checks if the attribute is there:
private static bool _isPassword(PropertyInfo p)
{
PasswordPropertyTextAttribute passProp = (PasswordPropertyTextAttribute)p.GetCustomAttribute(typeof(PasswordPropertyTextAttribute));
return (passProp != null); // Additional condition should go here
}
Now I would like to have my own logic here:
[PasswordPropertyText] should result in true.
[PasswordPropertyText(true)] should result in true.
[PasswordPropertyText(false)] should result in false.
but the default value of PasswordPropertyTextAttribute.Password is false when the argument is omitted.
Is there any way to get the raw attribute value?
Since attribute constructor information are stored as metadata as well you can get the required information by calling the GetCustomAttributesData method. Have a look at this simple example:
class Program
{
[PasswordPropertyText]
public string Password1 { get; set; }
[PasswordPropertyText(true)]
public string Password2 { get; set; }
[PasswordPropertyText(false)]
public string Password3 { get; set; }
static void Main(string[] args)
{
var props = typeof(Program).GetProperties();
foreach(var prop in props)
{
var attributeData = prop.GetCustomAttributesData().First(x => x.AttributeType == typeof(PasswordPropertyTextAttribute));
Console.WriteLine($"{prop.Name}: {(attributeData.ConstructorArguments.Cast<CustomAttributeTypedArgument?>().FirstOrDefault()?.Value ?? true)}");
}
Console.ReadLine();
}
}
Output:
Password1: True
Password2: True
Password3: False
What you're describing cannot be done using reflection.
Reflection is not looking at the code as it was written: it is looking at the model that results from that code. Since the default constructor for PasswordPropertyTextAttribute passes a false value to another constructor, the model that it produces is indistinguishable from using [PasswordPropertyText(false)].
If you want different behavior from the built-in attribute, I'd recommend creating your own attribute that has the behavior you're looking for instead.
In my application I have a custom attribute calles ResourceTargetAttribute which looks like:
[AttributeUsage(AttributeTargets.Property)]
private class ResourceTargetAttribute : Attribute
{
public ResourceTargetAttribute(string resourceKey)
{
ResourceKey = resourceKey;
}
public string ResourceKey { get; private set; }
}
The usage looks like:
[ResourceTarget("FileNotFoundErrorText")
public string FileNotFoundErrorText { get; private set; }
The constructor of the class where the FileNotFoundErrorText-Property is defined resolves this attribute. This just works fine.
Now I was thinking about to extend the attribute to have a parameterless constructor and if this is called the name of the Property the attribute is on will automatically be used for the ResourceKey.
Therefore I've introduced a new constructor which just looks like:
public ResourceTargetAttribute()
{
}
And the usage then should look like:
[ResourceTarget()]
public string FileNotFoundErrorText { get; private set; }
And here I want to have name of the FileNotFoundErrorText-Property automatically be passed to the ResourceTarget-Attribute.
Is there a possibility to do this?
The CallerMemberNameAttribute might help you:
public ResourceTargetAttribute([CallerMemberName] string propertyName = null)
{
ResourceKey = propertyName;
}
Usage:
[ResourceTarget]
public string FileNotFoundErrorText { get; private set; }
If you get the attribute, the
attr.ResourceKey
property should contain FileNotFoundErrorText as value.
Otherwise I just would go the way passing the name as string as attributes are metadata applied to the members of a type, the type itself, method parameters or the assembly so you must have the original member itself to access its meta data.
The easiest way would be to utilize nameof-operator:
[ResourceTarget(nameof(FileNotFoundErrorText)]
public string FileNotFoundErrorText { get; private set; }
Another approach would be to modify the code that actual examines / searches for these marker-attributes. use reflection to get the actual Property-Name on which the attribute was applied.
Maybe if you provide the mentioned "constructor-code" I could further assist.
I've refactored code like this:
public string CamelCASE { get; set; }
to:
public string CamelCase {get; set; }
only do discover that the input XML contains the former casing (let's call it a shouting camel). I have no control over how the XML document is produced. Nor do I burn of desire to retract my changes.
I'd like to map the loud camel property to a softly speaking one.
I've tried XmlElement and XmlMapping but to no greater success. A googling gave me only hits on how to map stuff to attributes, along lines of this post. However, I need only something like <LoudCAMEL> to be deserialized to a property public string QuietCamel.
Is there a smooth way to do so?
Edit
After adding the attribute as follows:
using System.Collections.Generic;
using System.Xml;
public class Beep : SuperBeep
{
private readonly BeepType _a;
public Beep() { _a = BeepType.SomeSome; }
public Beep(BeepType input) { _a = input; }
~Beep() { }
public override void Dispose() { }
public BeepType Aaa { get { return _a; } }
[XmlElement("CamelCASE")]
public bool CamelCase { get; set; }
}
I can see the red, wavy highlight telling me Cannot access constructor 'XmlElement' here due its protection level. When I compile, though, I get the IDE crying out loud that 'System.Xml.XmlElement' is not an attribute class.
Frankly, I'm a bit confused by the suggestion to use attributes (this is targeting .NET 2.0), since I was under the impression that attributing wasn't available to .NET prior to version 3.5. Am I mistaken?
[XmlElement("CamelCASE")]
public string CamelCase { get; set; }
should be all you need, if you are keeping the shouty name in the xml. If you want to use the quieter name in new xml, but allow the old name to still work, it gets more complicated. You could use:
public string CamelCase { get; set; }
[XmlElement("CamelCASE"), Browsable(false)]
[EditorBrowsable(EditorBrowsableState.Never)]
public string CamelCaseLegacy {
get { return CamelCase; }
set { CamelCase = value; }
}
[Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]
public bool ShouldSerializeCamelCaseLegacy() { return false; }
When serializing, the CamelCase property will serialize to <CamelCase>, and the CamelCaseLegacy element will be ignored due to the ShouldSerialize* method. However, when deserializing, the CamelCaseLegacy property will be used whenever <CamelCASE> is seen. We then map this value back to the CamelCase property.
You are referring to the wrong namespace.
Remove
using System.Xml;
and add
using System.Xml.Serialization;
I have one class which was serialized before. We have the xml output from it.
When we open the project we deserialize the xml to get the preserved objects.
Now i have added new bool property to class and since it is a new property, old xmls don't have this attribute. My deserialization works fine but assigns false to bool property, I want it to set true if its not there in XML. How can i achieve this ? I tried like this
public bool? _flag;
[XmlElement("Flag")]
public bool? flag
{
get
{
if (null != _flag)
{
return _flag;
}
return true;
}
set { _flag= value; }
}
You just need to add your default constructor and set it there. Here is an example:
public MyObject()
{
Flag = true;
}
EDIT
I'm not sure what's going on in your code, but this works perfectly fine:
public class MyObject
{
public MyObject()
{
Flag = true;
}
public bool Flag { get; set; }
public string Name { get; set; }
}
First, I didn't have the bool property there and serialized it to a file.. then for step 2, I added that bool property and the constructor.. then deserialized it from disk and it showed true, which is what I expected.
Please review your code, as I expect something else is going on. If you need help, post the full class here.
Suppose i have one customer class and i will serialize the class to xml. After serialization we will get xml data but i need some property of customer class to be serialized on demand based on few condition. Is it possible?
I have no concept how to do it. Can anyone help me with this?
You can add one or more ShouldSerializeXXXXXX() methods, where XXXXXX is the name of each property you want to serialize based on a condition.
E.g.:
public class Customer
{
[DefaultValue(null)]
public string SomeInfo { get; set; }
[DefaultValue(null)]
public string SomeOtherInfo { get; set; }
#region Serialization conditions
// should SomeInfo be serialized?
public bool ShouldSerializeSomeInfo()
{
return SomeInfo != null; // serialize if not null
}
// should SomeOtherInfo be serialized?
public bool ShouldSerializeSomeOtherInfo()
{
return SomeOtherInfo != null; // serialize if not null
}
#endregion
}
You can use XmlAttributeOverrides and overide the XmlIgnore attribute for your property.
(there is an example in the XmlIgnore msdn page)