大约有 41,000 项符合查询结果（耗时：0.0351秒） [XML]
What's the difference between ViewData and ViewBag?
...s advantage of the new dynamic features
in C# 4.0. ViewData requires typecasting for complex data type and
check for null values to avoid error. ViewBag doesn’t require
typecasting for complex data type.
ViewBag & ViewData Example:
public ActionResult Index()
{
ViewBag.Name = "...
new keyword in method signature
...ass.
Keep in mind that creating a "new" member is not polymorphic. If you cast the object to the base type, it will not use the derived type's member.
If you have a base class:
public class BaseClass
{
public void DoSomething() { }
}
And then the derived class:
public class DerivedType : B...
How to display gpg key details without importing it?
I have a copy of the postgresql apt repository gpg key and would like to view the details of the gpg key as it comes in the file. Is this possible without importing it into a key ring?
...
How do I obtain a Query Execution Plan in SQL Server?
...rosoft.com/sqlserver/2004/07/showplan' as sql),
CTE
as (SELECT CAST(TextData AS VARCHAR(MAX)) AS TextData,
ObjectID,
ObjectName,
EventSequence,
/*costs accumulate up the tree so the MAX should be the root*/
M...
The apk must be signed with the same certificates as the previous version
I had uploaded my app to Google Play (back when it was called Android Market) some time ago.
11 Answers
...
SQLAlchemy: how to filter date field?
...this might be obvious to some - this ONLY works because the func.date does CAST on the column which removes the time from equation => this does NOT mean range with the time! This only works when time is NOT in the column - you must CAST it to Date like this, or make the column Date, once it's Dat...
What is boxing and unboxing and what are the trade offs?
...
from C# 3.0 In a Nutshell:
Boxing is the act of casting a value
type into a reference type:
int x = 9;
object o = x; // boxing the int
unboxing is... the reverse:
// unboxing o
object o = 9;
int x = (int)o;
...
SQL NVARCHAR and VARCHAR Limits
... the length of the varchar(n) string is greater than 4,000 characters the cast will be to nvarchar(4000) and truncation will occur.
Datatypes of string literals
If you use the N prefix and the string is <= 4,000 characters long it will be typed as nvarchar(n) where n is the length of the string...
What is the difference between int, Int16, Int32 and Int64?
...ample works that way: the first literal 1, the 2, and the 3 are implicitly cast to short to fit them in the array, while the second literal 1 is left as an ordinary int. (int)1 is not considered equal to (short)1, (short)2, (short)3, thus the result is -1.
– user565869
...
Data binding to SelectedItem in a WPF Treeview
...
The cast to TreeViewItem fails for me I assume because I am using a HierarchicalDataTemplate applied from resources by datatype. But if you remove ChangeSelectedItem, then binding to a viewmodel and retrieving the item works fine...