As title, the following cases:
When the data in the List is tb_SensorRecordModel) type (class, reference data, can modify the values in the List;
When the data in the List is Int (a value of type integer data), can not modify the values in the List; Problem is how to change?

 
The namespace ConsoleApp9 
{
Public class tb_SensorRecordModel 
{
Public int ID {get; set; } 
Public decimal Value1 {get; set; } 
} 
Class Program 
{
The static void Main (string [] args) 
{
Console. WriteLine (" -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- tb_SensorRecordModelList -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- "); 
ListTb_SensorRecordModelList. Add (new tb_SensorRecordModel {ID=1, Value1=1}); 
Tb_SensorRecordModelList. Add (new tb_SensorRecordModel {ID=2, Value1=67}); 
Tb_SensorRecordModelList. Add (new tb_SensorRecordModel {ID=3, Value1=3}); 

//change the list of values of an element 
Tb_SensorRecordModel model1=tb_SensorRecordModelList. Where (=c & gt; C.I D==2). FirstOrDefault (); 
Console. WriteLine (" model1 original values for "+ model1. Value1); 
Model1. Value1 + +; 

Console. WriteLine (" model1 values increase after 1 for "+ model1. Value1); 

Tb_SensorRecordModel model2=tb_SensorRecordModelList. Where (=c & gt; C.I D==2). FirstOrDefault (); 
Console. WriteLine (" after step 1, tb_SensorRecordModelList value instead of "+ model2. Value1); 


Console. WriteLine (" -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- tb_SensorRecordModelList -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- "); 
List IntList=new List () {65, 66, 67, 68, 69}; 
Int findInt=67; 
Int IntTest1=IntList. Where (x=& gt; X.equals (findInt)). The First (); 
Console. WriteLine (" IntTest original values for "+ IntTest1); 
IntTest1 + +; 
Console. WriteLine (" IntTest values increase 1 for "+ IntTest1); 

Int IntTest2=IntList. Where (x=& gt; X.equals (findInt)). The First (); 
Console. WriteLine (" after step 1, ntTestList value instead of "+ IntTest2); 

Console.Read(); 
} 
} 
} 

CodePudding user response:

Can't, can only use a class package

CodePudding user response:

Can modify the values in the List, however,
To modify the List,
Rather than to modify an element of copy ,

 static void Main (string [] args) 
{
List IntList=new List () {65, 66, 67, 68, 69}; 
Int findInt=67; 
Var index=IntList. FindIndex (x=& gt; X==findInt);//find the location of the target under the IntList, 
Console. WriteLine (" IntTest original values for "+ IntList [index]); 
IntList [index] + +; 
Console. WriteLine (" IntTest values increase after 1 for "+ IntList [index]); 

Console.Read(); 
} 

CodePudding user response:

This is a typical value types and reference types you don't understand,

 int IntTest1=IntList. Where (x=& gt; X.equals (findInt)). The First (); 
Console. WriteLine (" IntTest original values for "+ IntTest1); 
IntTest1 + +; 

Change

 IntList. Where (x=& gt; X.equals (findInt)). The First () + +;