readonly

问题 I found a topic on MSDN that talks that yes, this is possible. I did a test that seems to break this statement: using System; namespace Test { class Program { static void Main(string[] args) { Foo f = new Foo("1"); Console.WriteLine(f.Bar); // prints 1 f.Test("2"); Console.WriteLine(f.Bar);// successfully prints 2 } } class Foo { public Foo(string b) { this.Bar = b; } public string Bar { get; private set; } public void Test(string b) { // this would be impossible for readonly field! // next

问题 I found a topic on MSDN that talks that yes, this is possible. I did a test that seems to break this statement: using System; namespace Test { class Program { static void Main(string[] args) { Foo f = new Foo("1"); Console.WriteLine(f.Bar); // prints 1 f.Test("2"); Console.WriteLine(f.Bar);// successfully prints 2 } } class Foo { public Foo(string b) { this.Bar = b; } public string Bar { get; private set; } public void Test(string b) { // this would be impossible for readonly field! // next

问题 There are many questions about this subject , but none (except one but still a short one) are dealing with the following scenario. From C# 4 book: Marc also wrote : if you change the value of a const, you need to rebuild all the clients Question : 1) Why is that? Are both static readonly and const — static ? 2) Where actually the values are saved ? 3) How does making a field static readonly actually solve this problem "behind the scene" ? 回答1: no, a const is a const, not a static - it is a

问题 I am developing ASP.NET application and I have problem with the EF 4.0 model. The EF model detects the newly added and deleted data, but not the modified data from the database. Here is an example of the problem what I have. A- Database: Script to generate the "Employees" database table CREATE TABLE [dbo].[Employees] ( [id] [int] IDENTITY(1, 1) NOT NULL, [name] [nvarchar](50) NULL, CONSTRAINT [PK_Employees] PRIMARY KEY CLUSTERED ( [id] ASC ) WITH ( PAD_INDEX = OFF, STATISTICS_NORECOMPUTE =

问题 We have a UI for an entity that either has an instrument or an issuer, but never both. You can select one of each from a popup search dialog and assign it to the entity. The user can see the number and name of each of the two next to the "Search..." button. Both of these must be non-editable, that is we the the respective <p:inputText ... readonly="true" ... /> to grey out the inputs. The requirement we have now is that not only a validation message is supposed to be shown when either none or

问题 We have a UI for an entity that either has an instrument or an issuer, but never both. You can select one of each from a popup search dialog and assign it to the entity. The user can see the number and name of each of the two next to the "Search..." button. Both of these must be non-editable, that is we the the respective <p:inputText ... readonly="true" ... /> to grey out the inputs. The requirement we have now is that not only a validation message is supposed to be shown when either none or

问题 I've faced with situation when I need to have EF readonly property in case of 'optimistic update'(you do not load current state of your domain object from database to check what properties are really changed. You just set your object as Modified and update it to database. You avoid redundant select and merge operations in this case). You can't write something like this : DataContext.Entry(entity).Property(propertyName).IsModified = false; , because setting of 'false' value is not supported

问题 What's the suggested "best practice" way to use Knockout's "attr" data binding with standalone attributes like "readonly" and "disabled" ? These attributes are special in that they are generally enabled by setting the attribute value to the attribute name (although many browsers work fine if you simply include the attribute names without any values in the HTML): <input type="text" readonly="readonly" disabled="disabled" value="foo" /> However, if you don't want these attributes to be applied,

问题 Update 2011-Jan-06: Believe it or not, I went ahead and incorporated this interface into an open source library I've started, Tao.NET. I wrote a blog post explaining this library's IArray<T> interface, which not only addresses the issues I originally raised in this question (a year ago?!) but also provides a covariant indexed interface , something that's sorely lacking (in my opinion) in the BCL. Question (in short): I asked why .NET has IList<T> , which implements ICollection<T> and

问题 I have the need to show some of my WPF Datagrid rows as read only or not depending on a property on my bound model. How can this be done? 回答1: I had the same problem. Using information provided in jsmith's answer and on Nigel Spencer's blog, I've come up with a solution that doesn't require changing WPF DataGrid source code, subclassing or adding code to view's codebehind . As you can see, my solution is very MVVM Friendly. It uses Expression Blend Attached Behavior mechanism so you'll need