小编Jim*_*988的帖子

是否可以像这样做一个OR语句？

WHERE pR.projectRelationId = '$id[ 0 ]' OR '$id[ 1 ]' OR '$id[ 2 ]'
AND pR.type = 'yada' AND

或者您是否必须继续重新进行比较:

        WHERE 
            pR.projectRelationId = '$id[ 0 ]' OR 
            pR.projectRelationId = '$id[ 1 ]' OR 
            pR.projectRelationId = '$id[ 2 ]'
            AND
            pR.type = 'yada' AND

我有一个功能:

public void Callback()
{
    // Does some stuff
}

我想将它传递给另一个函数,然后将其传递给另一个函数,然后执行函数...到目前为止我有这个:

public void StartApp() // entry point
{
    StartMyAwesomeAsyncPostRequest( Callback );
}

public void StartMyAwesomeAsyncPostRequest( Delegate callback )
{
    // Work out some stuff and start a post request
    TheActualAsyncPostRequest( callback );
}

public void TheActualAsyncPostRequest( Delegate callback )
{
    // Do some jazz then run the delegated function
    callback();
}

我看了几个其他的例子,但是来自PHP和javascript背景,我正在努力解释,你能不能给我一个特定于我的请求的例子或解释？提前致谢!

我创建了一个post请求类,我可以重用它来向外部api发出POST请求并返回它们发送给我的对象(JSON):

class PostRequest
    {
        private Action<DataUpdateState> Callback;

        public PostRequest(string urlPath, string data, Action<DataUpdateState> callback)
        {
            Callback = callback;

            // form the URI
            UriBuilder fullUri = new UriBuilder(urlPath);
            fullUri.Query = data;

            // initialize a new WebRequest
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(fullUri.Uri);
            request.Method = "POST";

            // set up the state object for the async request
            DataUpdateState dataState = new DataUpdateState();
            dataState.AsyncRequest = request;

            // start the asynchronous request
            request.BeginGetResponse(new AsyncCallback(HandleResponse),
                dataState);
        }

        private void HandleResponse(IAsyncResult asyncResult)
        {
            // get the state information
            DataUpdateState …

因为对API的Post请求需要在Windows Phone上异步运行,所以我很难创建一个易于使用的精简库来与API进行交互.

问题是使用库的人总是需要提供回调函数.

我们来看看一些伪代码:

PostRequest类帮助我处理POST请求:

class PostRequest
{
    private Action<MemoryStream> Callback;

    public PostRequest(string urlPath, string data, Action<MemoryStream> callback)
    {
        Callback = callback;

        // Form the URI
        UriBuilder fullUri = new UriBuilder(urlPath);

        if (!string.IsNullOrEmpty(data))
            fullUri.Query = data;

        // Initialize a new WebRequest
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(fullUri.Uri);
        request.Method = "POST";

        // Set up the state object for the async request
        DataUpdateState dataState = new DataUpdateState();
        dataState.AsyncRequest = request;

        // Start the asynchronous request
        request.BeginGetResponse(new AsyncCallback(HandleResponse),
            dataState);
    }

    private void HandleResponse(IAsyncResult asyncResult)
    { …

以下代码是非法的(Visual Studio 2012 Windows Phone(创建Windows Phone direct3d应用程序))

a non-value type cannot have any public data members 'posX'

头

ref class Placement sealed
{
public:
    Placement(
        float rotX, 
        float rotY, 
        float rotZ, 
        float posX, 
        float posY, 
        float posZ
    );
    float rotX, rotY, rotZ, posX, posY, posZ;
};

CPP

Placement::Placement(
        float rotX, 
        float rotY, 
        float rotZ, 
        float posX, 
        float posY, 
        float posZ
    )
    :   posX( posX ),
        posY( posY ),
        posZ( posZ )
{
    this->rotX = static_cast<float>(rotX);
    this->rotY = static_cast<float>(rotY);
    this->rotZ = …

我有一个小行星类:

class Asteroid
{
public:
    Asteroid();

    float GetMovementSpeed();
    float GetRotationSpeed();

    Placement^ GetCurrentOrientation();
    void UpdateOrientation( Placement^ placement );

    float GetPosX();
    float GetPosY();
    float GetPosZ();

    float GetRotX();
    float GetRotY();
    float GetRotZ();
private:
    float movementSpeed;
    float rotationSpeed;

    Placement^ placement;

    //float x;
    //float y;
    //float z;

    //float rotX;
    //float rotY;
    //float rotZ;
};

我已经设置了以下向量并用小行星填充它:) ...

vector<Asteroid*> asteroids;

asteroids.push_back( new Asteroid() );
asteroids.push_back( new Asteroid() );
asteroids.push_back( new Asteroid() );

for(std::vector<Asteroid*>::iterator asteroid = asteroids.begin(); asteroid != asteroids.end(); ++asteroid) 
{
    asteroid-> //Can't access the methods of …

例如,如果我希望我的类属性可以这样命名为笑:

class Product
{
   [Key]
   int ProductID {get;set;}

   [Required]
   string TitleTOTHEMAX {get;set;}
}

我的Sql表有2列"ProductID"和"Title",我怎么告诉类的属性将自己映射到"Title"列,考虑到"TitleTOTHEMAX"列不存在:)

我有以下三个标题:

IBaseStates.h

class IBaseStates
{
public:
    enum STATE;

    virtual void Update( STATE state ) = 0;
};

PlayerStates.h

#pragma once

#include "IBaseStates.h"
#include "Player.h"

class PlayerStates : public IBaseStates, public Player
{
public:
    enum STATE {
        FLYING,
        FALLING
    };

    int textureAmount;

    PlayerStates();
    ~PlayerStates( );

    void Update( STATE state );
};

Player.h

#pragma once

#include "StructVertex.h"
#include "SquareVertices.h"
#include "WICTextureLoader.h"

using namespace Microsoft::WRL;
using namespace DirectX;
//using namespace DirectX;

class Player : public SquareVertices
{
public:
    Player( ComPtr<ID3D11Device1> d3dDevice );
    ~Player(); …

如果我有:

var greeter: Greeter = new Sausage();

并且Greeter类和Sausage类都具有相同的功能和属性,变量greeter将很高兴地填满Sausage... ...我怎么能阻止它？

例如,以下代码编译正常:(

class Greeter {
    greeting: string;
    constructor(message: string) {
        this.greeting = message;
    }
    greet() {
        return "Hello, " + this.greeting;
    }
}

class Sausage {
    size: number;
    name: string;
    greeting: string;

    constructor() {
        this.size = this.SausageLogic(); 
    }

    private SausageLogic(): number {
        return this.size * 3;
    }
    greet() {
        return "Hello, ";
    }
}

var greeter: Greeter = new Sausage();

有什么区别:

public List<MyType> Something{ get; set; } = new List<MyType>();

和

public List<MyType> Something{ 
    get{
        return new List<MyType>();
    }
    //set...
}

上下文:
我不确定我在代码中看到的行为.构造函数null上有一个服务,但在未来的方法调用中,我假设的是类的相同实例.