Jul 30, 2008 if you are working with silverlight and data you most likely are going to leverage data binding at some point and run into some needs to format the data in the xaml. To reach this goal, you can use a dependencyproperty. And by the way, can we do this binding on the converterparameter property. Lets say i have a few datatemplates and i want to select one of them into my usercontrol based on a criteria in my viewmodel. One more features of silverlight for data biniding process is ivalueconverter.
Of course value converters can be generalized an reused. Aug 03, 2008 in the property changed event handler of the binding we must force the bindingexpression to update and change the value of the converter parameter. Looks like youre trying to bind to a converterparameter which im afraid you cant. Pass value of a field to silverlight converterparameter stack. Silverlight multibindings, how to attach multiple bindings. First of all, i wanted to recreate the imultivalueconverter from wpf in its entirety. One of the things i hear often in forums and also lately on the wpf disciples mailing list is, how come i cannot use binding in converterparameters. Ivalueconverter add the converter into the user controls resources. Convert method which is filled with any string supplied by the user in markup through the converterparameter attribute of the binding markup extension. Once ive added that code, public class datetostringconverter.
Ivalueconverter, converter, staticresource, visibility. Valueconverter in flexgrid column silverlight edition. Lets explore what im talking about using a common formatting need. Public function convert byval value as object, byval targettype as system. Luckily this can be done using value converters, which have been available for wpf since its inception as well. The convertback method lets us update the binding source. However, even though wpf supports this property bag type of binding, there is no way to do this directly in silverlight. Thats normally a very easy step, but i spend some extraordinary time with my converter becuase in my case the second parameter should be bindable. Using convertback method in an ivalueconverter silverlight wpf. Set the valueconverter after setting the column binding and everything will work fine. The silverlight interface is a simple series of control, that can be bound to a dto, so the typical pattern is to ask service for some object, then bind them to a control, let the user play with the interface and thanks to twoway binding we can simply wait for the user to press a save button or other such events to call update method from. This blog post was written with a sl2 datagrid, for sl3, please see my updated blog post in my previous blog post i described a method for solving the commonly faced problem of binding a silverlight datagrid to dynamic data, the form of which is not know at compile time. Silverlight, bitmapimage, url, ivalueconverter, cultureinfo, and convertback.
Data binding is one of my favorite features and something that i use a lot while building silverlight applications. For example, if you have an application that stores temperatures, you might use a converter to map the temperature to the image of. However, when building user interfaces with wpf silverlight, you often need to create your own value converters. Data binding using ivalueconverter in silverlight codeproject. In this example that is the isonspecial value from the product class. Binding a silverlight datagrid to dynamic data part 2. However, when building user interfaces with wpfsilverlight, you often need to create your own value converters. How to bind a parameter within a converter which implements ivalueconverter. We will support any number of input data fields and also property paths to enable binding against object graphs. Convertbackobject value, type targettype, object parameter, system. Gets or sets a parameter that can be used in the converter logic. In the convert method the main parameter you will be working with is the value parameter.
Im sticking to a really simple data definition for binding. Silverlight multibindings, how to attached multiple. When the binding which this expression represents is associated with an element, the binding source will be the possibly inherited datacontext of the target element. We make use of ivalueconverter class to provide the values from the grouped rows. The techniques explained are illustrated in the following demo. Wpf bind value to binding converterparameter michlgs blog. Wpf binding converter parameter including discussion. Is it possible to use binding with ivalueconverter to color a column based on values from two different cells. Type, byval parameter as object, byval culture as system.
If you are working with silverlight and data you most likely are going to leverage data binding at some point and run into some needs to format the data in the xaml. How to pass targettype parameter to the convert method of the ivalueconverter instance in xaml hot network questions what are typical values of the lifttodrag ratio for normal small aircraft. Moreover if you want to learn about the binding in wpf you can check my this article and. This blog post was written with a sl2 datagrid, for sl3, please see my updated blog post. First, we look at the code to define the binding for c1chart values. So, you can now declare a dependency property for each parameter you need in your converter and bind it in silverlight 4.
As you cant pass anything but a literal into the converterparameter the solution is to pass the whole object into the converter and then you can access all of its properties from within the converter so your code becomes assuming your object is called match public function convert byval value as object, byval targettype as system. The following example shows how to implement the ivalueconverter interface and use the converter when data binding to a collection of objects. Ivalueconverter in wpf data binding example, value conversion with ivalueconverter the complete wpf tutorial, wpf introduction. A common mistake is to implement custom value converters for each and every binding that requires one. I have extended this technique to add include change notification so that the datagrid can be made editable. Converterparameter to illustrate this example, here is my scenario. Sep 16, 2009 we make use of the parameter parameter of the ivalueconverter. Aug 21, 2009 data binding is one of my favorite features and something that i use a lot while building silverlight applications. Ill cover the following topics in the code samples below. Pass value of a field to silverlight converterparameter.
Ivalueconverter is used for formatting and binding data to silverlight xaml control. Dim formatstring as string trycast parameter, string if. Binding with converter using converterparameter binding. Ivalueconverter, converter, staticresource, visibility, system. Background when we are binding data to controls there will be times when the data needs to be modified. I have omitted errorvalidations in the code,as it adds extra code which obscures the relevant code that implements the idea of the solution. Net generic custom wpf silverlight value converters. Convert retrieve the format string and use it to format the value. The chart is already bound to the collection of groupedrows. A converter is a powerful concept with wpf and silverlight. Wpf binding converter parameter including discussion about.
Grid control is used to display the factual data while chart control is used to analyze that data. Binding combobox to enum in silverlight alkampfers place. We will bind c1flexgrid to a collectionviewsource and define the required groupdescriptions. Sometimes it is necessary that you have a converter interface ivalueconverter with multiple parameters. Using a valueconverter as a datatemplateselector in. For example, if you have an application that stores temperatures, you might use a converter to map the temperature to the image of a thermometer that visually represents the temperature. Silverlight multibindings, how to attach multiple bindings to. Ive addressed this issue before in a different way, and i think this is much better see imultivalueconverter with silverlight. Bindable converter, converter parameter and stringformat. Given that the visibility property is not of type bool, instead, it is of type visibility. For example, if you have a grid with two columns, valid, and duedate, and i want to color the cell for duedate if the value is less than the current date and if the valid cell contains true. Today just a quick tip on a frequently asked question. Wpf snippet setting a binding on a converter parameter.
Wpf, silverlight, winrt, universal windows platform, etc. It allows developers to achieve more with less code. Jun 23, 2010 is it possible to use binding with ivalueconverter to color a column based on values from two different cells. Dan wahlin creating a silverlight datacontext proxy to. Thats normally a very easy step, but i spend some extraordinary time with my converter becuase in. It implements ivalueconverter and allows you to map a value to a display entity. Data binding is one of the most powerful features of wpfsilverlight. Part 25 advanced binding with value converters windows phone. Gridviewcomboboxcolumn background binding support in ui. Ivalueconverter with multiple columns in ui for silverlight. This post demonstrates a technique for binding a silverlight datagrid to dynamic data, the structure of which is not know at compiletime.
May 14, 2012 download source code for working with silverlight datagrid control introduction datagrid control is a very old and well known control in the dotnet community and every presentation framework supported by microsoft so far has this component. Using multiple bindings and ivalueconverter for complex templates im going to give a simple example, but by complex i think youll see how this can be extended. My converter was updated to implement imultivalueconverter, and became the following. Luckily this can be done using value converters, which have been available for wpf since its inception a. Binding aggregate values from c1flexgrid to c1chart for. These solutions are alternatives to the ones described in the article bindingable converter parameter, and other blogs and fora. Part 25 advanced binding with value converters windows. String format this is the second substantial coding post to reach my goal of three by the end of the year. We can also use it to bind between dependency properties of two different resources. Using a valueconverter as a datatemplateselector in silverlight. For an example that shows how to implement the convert method using the parameter and language parameters, see the ivalueconverter interface. We make use of the parameter parameter of the ivalueconverter. When using converters for data binding, we usually use the convert method of an ivalueconverter and just leave the convertback method unimplemented.
Silverlight ivalueconverter for image urls silverlight wpf. Apr 11, 2016 in this article i will discuss about the ivalueconverter interface of the wpf framework which is present in the presentationframework assembly. The source code of the demo can be downloaded below. Binding with converter using converterparameter binding not working.
In this article we develop ways to overcome the limitation that converterparameter cannot be specified as dynamic binding in wpf and silverlight 5. Convertbackobject, type, object, string xaml data binding sample. Microsoft silverlight will reach end of support after october 2021. First, ill make the class public and ill require it to implement ivalueconverter. Aug 02, 2011 one more features of silverlight for data biniding process is ivalueconverter. To get this type of binding to work you can use an ivalueconverter. Using ivalueconverter to binding data in windows phone chao cac b. In this article i will discuss about the ivalueconverter interface of the wpf framework which is present in the presentationframework assembly. Data binding is one of the most powerful features of wpf silverlight. Odegaard was binding to a dictionary object and was trying to get one of the keys to show up in his textblock. Using a value converter to bind to visibility in the. Using ivalueconverter to binding data in windows phone.
Apr 17, 2009 this post demonstrates a technique for binding a silverlight datagrid to dynamic data, the structure of which is not know at compiletime. Net generic custom wpfsilverlight value converters. This can be done quite easily one would say but there are 2 main problems. One of the key binding features missing from silverlight 3 is. This blog post extends on the method previously described, adding change notification, allowing the datagrid to. The columnvalueselector is a converter class extended from ivalueconverter. Since the binding is null at the time when valueconverter is set, the converter does not get assigned to the binding object. How to work around that bindings converter, convertparameter and stringformat cannot be. This converter is used to get the column value of the current row.
In my project, ive created a class named booleantovisibilityconverter, which implements the interface ivalueconverter. Ah if i could only bind it to something in my viewmodel. In this blog, we will look at a simple plotting demonstration of the aggregate values of the grouped rows from c1flexgrid into c1chart for silverlight. A value converter allows you to perform a conversion on the data to format the data, change the. I will discuss about the syntax of using the ivalueconvertor with binding class in the xaml with code example. We would like to show you a description here but the site wont allow us. If you are working with silverlight and data you most likely are going to. At the time of this writing, silverlight did not support rendering. Ivalueconverter class is defined to return the required value from the groupedrow. Oct 02, 2015 a binding cannot be set on the converterparameter property of type binding after some googling around, it turns out that the solution is to use a multibinding converter. Binding with converter using converterparameter binding not. Bind a color property from based on the class property if the item is selected. Simply bind your image url string property of your data class to the source property of the image class using the ivalueconverter.
Ivalueconverter example and usage in wpf codeproject. Binding a silverlight datagrid to dynamic data via idictionary. It is provided as a parameter to convert and convertback method of converter whenever any update in source or target of binding takes place. Ivalueconverter for bool to visibility silverlight wpf. Silverlight data binding and value converters tim heuer. Exposes methods that allow the data to be modified as it passes through the binding engine. Using an ivalueconverter in a binding download source code for working with silverlight datagrid control introduction datagrid control is a very old and well known control in the dotnet community and every presentation framework supported by microsoft so far has this component. Use a datagridtemplatecolumn to define the optional button, and data bind the visibility property of the button to the boolean data source property, specifying the converter. Converter class must implement ivalueconverter interface. Therefore, in order to allow binding on the multibinding class, it must be a frameworkelement, this gives us the datacontext property and the setbinding method.
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