C#工作笔记

没想到一个Java后端开发还要负责C#桌面程序，我感觉有点方。不过方归方，活还是要干的。简单记录下学到的一些知识点。

1.引用API函数

namespace Demo
{
class MyUtil
{
[DllImport("user32.dll", EntryPoint = "keybd_event")]
public static extern void keybd_event(
byte bVk,       //虚拟键值
byte bScan,     // 一般为0
int dwFlags,    //这里是整数类型 0 为按下，2为释放
int dwExtraInfo //这里是整数类型 一般情况下设成为0
);

public static void sendF9()
{
keybd_event((byte)Keys.F9, 0, 0, 0);
keybd_event((byte)Keys.F9, 0, 2, 0);
}
}
}

2.对象序列化，因为要对接Java的rest接口，所以需要将对象序列化转json

using System.Runtime.Serialization;

namespace Demo
{
[DataContract]
class ServiceError
{
[DataMember]
public string errCode { get; set; }

[DataMember]
public string errDesc { get; set; }
}
}

/// <summary>
/// 将对象转化为JSON字符串
/// </summary>
/// <param name="obj"></param>
/// <returns></returns>
public static string ObjectToJson(object obj)
{
DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
MemoryStream stream = new MemoryStream();
serializer.WriteObject(stream, obj);
byte[] dataBytes = new byte[stream.Length];
stream.Position = 0;
stream.Read(dataBytes, 0, (int)stream.Length);
return Encoding.UTF8.GetString(dataBytes);
}

/// <summary>
/// 将Json字符串转化成对象
/// </summary>
/// <typeparam name="T">转换的对象类型</typeparam>
/// <param name="output">json字符串</param>
/// <returns></returns>
public static T ToClass<T>(string output)
{
object result = null;
DataContractJsonSerializer outDs = new DataContractJsonSerializer(typeof(T));
using (MemoryStream outMs = new MemoryStream(Encoding.UTF8.GetBytes(output)))
{
try
{
result = outDs.ReadObject(outMs);
}
catch (SerializationException ex)
{
Console.WriteLine(ex.TargetSite + ": " + ex.Message);
Console.WriteLine(ex.StackTrace);
}
}
return (T)result;
}

3.发送POST请求

/// <summary>
/// POST请求与获取结果
/// </summary>
public static string HttpPost(string Url, string postDataStr)
{
Console.WriteLine("HttpPost: postDataStr = " + postDataStr);
string retVal = string.Empty;
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
request.Method = "POST";
request.ContentType = "application/json";
StreamWriter writer = new StreamWriter(request.GetRequestStream(), Encoding.ASCII);
writer.Write(postDataStr);
writer.Flush();

HttpWebResponse response = (HttpWebResponse)request.GetResponse();
string encoding = response.ContentEncoding;
if (encoding == null || encoding.Length < 1)
{
encoding = "UTF-8"; //默认编码
}
StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding(encoding));
retVal = reader.ReadToEnd();
}
catch (Exception ex)
{
Console.WriteLine(ex.TargetSite + ": " + ex.Message);
Console.WriteLine(ex.StackTrace);
}
Console.WriteLine("HttpPost: retVal = " + retVal);
return retVal;
}