I have a LookUpEdit control and I need set property value to NullText with reflection, but I'm getting the TargetException:
private static void SetObjectProperty(string propiedad, string valor, object obj)
{
if (obj.GetType() == typeof(LookUpEdit))
{
string[] vv = propiedad.Split('.');
string prop = vv[0];
string propType = vv[1];
var p = obj.GetType().GetProperty(prop, BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly);
PropertyInfo propertyInfo = p.PropertyType.GetProperty(propType);
if (propertyInfo != null)
{
propertyInfo.SetValue(obj, valor, null);
}
}
}
I only get the exception with LookUpEdit control.
"propiedad" is a string contains "Properties.NullText" so this is why I'm doing a split
You should apply operations with nested properties to corresponding nested objects:
static void SetObjectProperty(object obj, string propertyPath, object value) {
if(obj != null && obj.GetType() == typeof(LookUpEdit)) {
string[] parts = propertyPath.Split('.');
var rootInfo = typeof(LookUpEdit).GetProperty(parts[0],
BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly);
object root = rootInfo.GetValue(obj); // obtaining a root
var nestedInfo = rootInfo.PropertyType.GetProperty(parts[1]);
if(nestedInfo != null)
nestedInfo.SetValue(root, value, null); // using root object
}
}
PS. Why you're using this ugly way of modifying object properties?
I'm looking to do something like this:
string currPanel = "Panel";
currPanel += ".Visible"
Now at this point I have a string variable with the name of a property that only accepts Boolean values. Can I some how do something like this:
<data type> currPanel = true;
so the actual property Panel1.Visible accepts it without any errors?
Supporting both properties and fields, but only instance ones:
public static void SetValue(object obj, string name, object value)
{
string[] parts = name.Split('.');
if (parts.Length == 0)
{
throw new ArgumentException("name");
}
PropertyInfo property = null;
FieldInfo field = null;
object current = obj;
for (int i = 0; i < parts.Length; i++)
{
if (current == null)
{
throw new ArgumentNullException("obj");
}
string part = parts[i];
Type type = current.GetType();
property = type.GetProperty(part, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
if (property != null)
{
field = null;
if (i + 1 != parts.Length)
{
current = property.GetValue(current);
}
continue;
}
field = type.GetField(part, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
if (field != null)
{
property = null;
if (i + 1 != parts.Length)
{
current = field.GetValue(current);
}
continue;
}
throw new ArgumentException("name");
}
if (current == null)
{
throw new ArgumentNullException("obj");
}
if (property != null)
{
property.SetValue(current, value);
}
else if (field != null)
{
field.SetValue(current, value);
}
}
example of use:
public class Panel
{
public bool Visible { get; set; }
}
public class MyTest
{
public Panel Panel1 = new Panel();
public void Do()
{
string currPanel = "Panel1";
currPanel += ".Visible";
SetValue(this, currPanel, true);
}
}
and
var mytest = new MyTest();
mytest.Do();
Note that I'm not supporting indexers (like Panel1[5].Something). Supporting int indexers would be feasible (but another 30 lines of code). Supporting not-int indexers (like ["Hello"]) or multi-key indexers (like [1, 2]) would be quite hard.
From what I can see here is that you are using WPF. Things like this you accomplish with converters
http://www.codeproject.com/Tips/285358/All-purpose-Boolean-to-Visibility-Converter
With MVVM and WPF you never need to do this
I am facing a problem about PropertyInfo .My code is here
Type type = typeof(T);
PropertyInfo propertyInfo = type.GetProperty(filterDescriptor.Member);
if (propertyInfo != null && propertyInfo.PropertyType.FullName.ToLower() == "system.string")
{
isMemberStringType = true;
filterDescriptor.Value = filterDescriptor.Value ?? string.Empty;
}
Problem is propertyInfo getting NULL if filterDescriptor.Member contains value like
abc.key
abc.Name
But when it contains Just Key and Name ,It works,it get system.string and execute if .How do i over come this.Help.
MSDN documentation makes it very clear:
Parameters
name
Type: System.String
The string containing the name of the public property to get.
No class can contain property with dot (.) in name.
What you are trying to achieve (I think) is to check child property (e.g. your class has property named abc and class of that property has its own property named key).
To do so, you have to use recursion.
public bool HasPropertyInPath(
Type checkedType,
string propertyPath,
Type propertyType)
{
int dotIndex = propertyPath.IndexOf('.');
if (dotIndex != -1)
{
PropertyInfo topPropertyInfo
= checkedType.GetProperty(propertyPath.Substring(0, dotIndex));
if (topPropertyInfo == null)
{
return false;
}
return HasPropertyInPath(
topPropertyInfo.PropertyType,
propertyPath.Substring(dotIndex + 1),
propertyType);
}
PropertyInfo propertyInfo = checkedType.GetProperty(propertyPath);
return (propertyInfo != null && propertyInfo.PropertyType == propertyType);
}
Then you can use it like this:
if (HasPropertyInPath(typeof(T), filterDescriptor.Member, typeof(string))
{
isMemberStringType = true;
filterDescriptor.Value = filterDescriptor.Value ?? string.Empty;
}
Above code is not tested but should check children properties.
This is not possible with simple call of GetProperty because it works only for the current object level. What you want to do is to traverse nested properties. And you should to remember about treating collections differently (because you want to see their elements properties, not the properties of the collection itself):
static System.Reflection.PropertyInfo GetProperty(Type type, string propertyPath)
{
System.Reflection.PropertyInfo result = null;
string[] pathSteps = propertyPath.Split('.');
Type currentType = type;
for (int i = 0; i < pathSteps.Length; ++i)
{
string currentPathStep = pathSteps[i];
result = currentType.GetProperty(currentPathStep);
if (result.PropertyType.IsArray)
{
currentType = result.PropertyType.GetElementType();
}
else
{
currentType = result.PropertyType;
}
}
return result;
}
and then you can 'query' objects with 'paths':
PropertyInfo pi = GetProperty(c1.GetType(), "ArrayField1.Char");
PropertyInfo pi2 = GetProperty(c2.GetType(), "Color");
See more for reference in this answer.
i have used the following code to change the current value for the current field value as
FieldInfo connectionStringField = GetType().BaseType.GetField("_sqlConnectionString", BindingFlags.Instance | BindingFlags.NonPublic);
connectionStringField.SetValue(this, connectionString);
but my query is to get current value of connectionstringfied...
i tried the below code as
getvalue(obj ss);
waiting for your valuable esponses
it throws me null values
If connectionStringField has found the field (i.e. it is in the base type and is called "_sqlConnectionString", then it should just be:
string connectionString = (string)connectionStringField.GetValue(this);
?
However, using reflection to talk to non-public fields is... unusual.
public static string GetPropertyValue<T>(this T obj, string parameterName)
{
PropertyInfo[] property = null;
Type typ = obj.GetType();
if (listPropertyInfo.ContainsKey(typ.Name))
{
property = listPropertyInfo[typ.Name];
}
else
{
property = typ.GetProperties();
listPropertyInfo.TryAdd(typ.Name, property);
}
return property.First(p => p.Name == parameterName).GetValue(obj, null).ToString();
}
listPropertyInfo is a cache to avoid reflection performance issue
public static void SetPropertyValue<T>(this T obj, string parameterName, object value)
{
PropertyInfo[] property = null;
Type typ = obj.GetType();
if (listPropertyInfo.ContainsKey(typ.Name))
{
property = listPropertyInfo[typ.Name];
}
else
{
property = typ.GetProperties();
listPropertyInfo.TryAdd(typ.Name, property);
}
if (value == DBNull.Value)
{
value = null;
}
property.First(p => p.Name == parameterName).SetValue(obj,value, null);
}
I used the same trick for setters
From the world of PHP I have decided to give C# a go. I've had a search but can't seem to find the answer of how to do the equivalent to this.
$object = new Object();
$vars = get_class_vars(get_class($object));
foreach($vars as $var)
{
doSomething($object->$var);
}
I basically have a List of an object. The object could be one of three different types and will have a set of public properties. I want to be able to get a list of the properties for the object, loop over them and then write them out to a file.
I'm thinking this has something to do with c# reflection but it's all new to me.
Any help would be greatly appreciated.
This should do it:
Type myType = myObject.GetType();
IList<PropertyInfo> props = new List<PropertyInfo>(myType.GetProperties());
foreach (PropertyInfo prop in props)
{
object propValue = prop.GetValue(myObject, null);
// Do something with propValue
}
void Test(){
var obj = new{a="aaa", b="bbb"};
var val_a = obj.GetValObjDy("a"); //="aaa"
var val_b = obj.GetValObjDy("b"); //="bbb"
}
//create in a static class
static public object GetValObjDy(this object obj, string propertyName)
{
return obj.GetType().GetProperty(propertyName).GetValue(obj, null);
}
Yes, Reflection would be the way to go. First, you would get the Type that represents the type (at runtime) of the instance in the list. You can do this by calling the GetType method on Object. Because it is on the Object class, it's callable by every object in .NET, as all types derive from Object (well, technically, not everything, but that's not important here).
Once you have the Type instance, you can call the GetProperties method to get the PropertyInfo instances which represent the run-time informationa about the properties on the Type.
Note, you can use the overloads of GetProperties to help classify which properties you retrieve.
From there, you would just write the information out to a file.
Your code above, translated, would be:
// The instance, it can be of any type.
object o = <some object>;
// Get the type.
Type type = o.GetType();
// Get all public instance properties.
// Use the override if you want to classify
// which properties to return.
foreach (PropertyInfo info in type.GetProperties())
{
// Do something with the property info.
DoSomething(info);
}
Note that if you want method information or field information, you would have to call the one of the overloads of the GetMethods or GetFields methods respectively.
Also note, it's one thing to list out the members to a file, but you shouldn't use this information to drive logic based on property sets.
Assuming you have control over the implementations of the types, you should derive from a common base class or implement a common interface and make the calls on those (you can use the as or is operator to help determine which base class/interface you are working with at runtime).
However, if you don't control these type definitions and have to drive logic based on pattern matching, then that's fine.
well, in C# it's similar.
Here's one of the simplest examples (only for public properties):
var someObject = new { .../*properties*/... };
var propertyInfos = someObject.GetType().GetProperties();
foreach (PropertyInfo pInfo in propertyInfos)
{
string propertyName = pInfo.Name; //gets the name of the property
doSomething(pInfo.GetValue(someObject,null));
}
One line solution using Linq...
var obj = new {Property1 = 1, Property2 = 2};
var property1 = obj.GetType().GetProperties().First(o => o.Name == "Property1").GetValue(obj , null);
To get specific property value from property name
public class Bike{
public string Name {get;set;}
}
Bike b = new Bike {Name = "MyBike"};
to access property value of Name from string name of property
public object GetPropertyValue(string propertyName)
{
//returns value of property Name
return this.GetType().GetProperty(propertyName).GetValue(this, null);
}
You can use GetType - GetProperties - Linq Foreach:
obj.GetType().GetProperties().ToList().ForEach(p =>{
//p is each PropertyInfo
DoSomething(p);
});
Here's something I use to transform an IEnumerable<T> into a DataTable that contains columns representing T's properties, with one row for each item in the IEnumerable:
public static DataTable ToDataTable<T>(IEnumerable<T> items)
{
var table = CreateDataTableForPropertiesOfType<T>();
PropertyInfo[] piT = typeof(T).GetProperties();
foreach (var item in items)
{
var dr = table.NewRow();
for (int property = 0; property < table.Columns.Count; property++)
{
if (piT[property].CanRead)
{
var value = piT[property].GetValue(item, null);
if (piT[property].PropertyType.IsGenericType)
{
if (value == null)
{
dr[property] = DBNull.Value;
}
else
{
dr[property] = piT[property].GetValue(item, null);
}
}
else
{
dr[property] = piT[property].GetValue(item, null);
}
}
}
table.Rows.Add(dr);
}
return table;
}
public static DataTable CreateDataTableForPropertiesOfType<T>()
{
DataTable dt = new DataTable();
PropertyInfo[] piT = typeof(T).GetProperties();
foreach (PropertyInfo pi in piT)
{
Type propertyType = null;
if (pi.PropertyType.IsGenericType)
{
propertyType = pi.PropertyType.GetGenericArguments()[0];
}
else
{
propertyType = pi.PropertyType;
}
DataColumn dc = new DataColumn(pi.Name, propertyType);
if (pi.CanRead)
{
dt.Columns.Add(dc);
}
}
return dt;
}
This is "somewhat" overcomplicated, but it's actually quite good for seeing what the outcome is, as you can give it a List<T> of, for example:
public class Car
{
string Make { get; set; }
int YearOfManufacture {get; set; }
}
And you'll be returned a DataTable with the structure:
Make (string)
YearOfManufacture (int)
With one row per item in your List<Car>
This example trims all the string properties of an object.
public static void TrimModelProperties(Type type, object obj)
{
var propertyInfoArray = type.GetProperties(
BindingFlags.Public |
BindingFlags.Instance);
foreach (var propertyInfo in propertyInfoArray)
{
var propValue = propertyInfo.GetValue(obj, null);
if (propValue == null)
continue;
if (propValue.GetType().Name == "String")
propertyInfo.SetValue(
obj,
((string)propValue).Trim(),
null);
}
}
I haven't found this to work on, say Application objects. I have however had success with
var serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
string rval = serializer.Serialize(myAppObj);
You can try this:
string[] arr = ((IEnumerable)obj).Cast<object>()
.Select(x => x.ToString())
.ToArray();
Once every array implements IEnumerable interface
public Dictionary<string, string> ToDictionary(object obj)
{
Dictionary<string, string> dictionary = new Dictionary<string, string>();
Type objectType = obj.GetType();
IList<PropertyInfo> props = new List<PropertyInfo>(objectType.GetProperties());
foreach (PropertyInfo prop in props)
{
object propValue = prop.GetValue(obj, null);
dictionary.Add(prop.Name, propValue.ToString());
}
return dictionary;
}
/// get set value field in object to object new (two object field like )
public static void SetValueObjectToObject (object sourceObj , object resultObj)
{
IList<PropertyInfo> props = new List<PropertyInfo>(sourceObj.GetType().GetProperties());
foreach (PropertyInfo prop in props)
{
try
{
//get value in sourceObj
object propValue = prop.GetValue(sourceObj, null);
//set value in resultObj
PropertyInfo propResult = resultObj.GetType().GetProperty(prop.Name, BindingFlags.Public | BindingFlags.Instance);
if (propResult != null && propResult.CanWrite)
{
propResult.SetValue(resultObj, propValue, null);
}
}
catch (Exception ex)
{
// do something with Ex
}
}
}