c#进程之间对象传递方法
作者:楚人无衣
1. 起源
KV项目下载底层重构升级决定采用独立进程进行Media下载处理,以能做到模块复用之目的,因此涉及到了独立进程间的数据传递问题。
目前进程间数据传递,多用WM_COPYDATA、共享dll、内存映射、Remoting等方式。相对来说,WM_COPYDATA方式更为简便,网上更到处是其使用方法。
而且Marshal这个静态类,其内置多种方法,可以很方便实现字符串、结构体等数据在不同进程间传递。
那么,对象呢?如何传递?
2、序列化
想到了,Newtonsoft.Json.dll这个神器。相对于内建的XmlSerializer这个东西,我更喜欢用Json。
那么,如此处理吧,我们来建个Demo解决方案,里面有HostApp、ClildApp两个项目,以做数据传递。
3、ChildApp项目
先说这个,我没有抽取共用的数据单独出来,而做为Demo,直接写入此项目中,HostApp引用此项目,就可引用其中public出来的数据类型。
数据结构部分代码:
[StructLayout(LayoutKind.Sequential)] public struct COPYDATASTRUCT { public IntPtr dwData; public int cbData; [MarshalAs(UnmanagedType.LPStr)] public string lpData; } [Serializable] public class Person { private string name; private int age; private List<Person> children; public Person(string name, int age) { this.name = name; this.age = age; this.children = new List<Person>(); } public string Name { get { return this.name; } set { this.name = value; } } public int Age { get { return this.age; } set { this.age = value; } } public List<Person> Children { get { return this.children; } } public void AddChildren() { this.children.Add(new Person("liuxm", 9)); this.children.Add(new Person("liuhm", 7)); } public override string ToString() { string info = string.Format("姓名:{0},年龄:{1}", this.name, this.age); if (this.children.Count != 0) { info += (this.children.Count == 1) ? "\r\n孩子:" : "\r\n孩子们:"; foreach (var child in this.children) info += "\r\n" + child.ToString(); } return info; } }
窗体代码:
public partial class ChildForm : Form { public const int WM_COPYDATA = 0x004A; private IntPtr hostHandle = IntPtr.Zero; Person person = new Person("liujw", 1999); [DllImport("User32.dll", EntryPoint = "SendMessage")] private static extern int SendMessage( IntPtr hWnd, // handle to destination window int Msg, // message int wParam, // first message parameter ref COPYDATASTRUCT lParam // second message parameter ); public ChildForm(string[] args) { InitializeComponent(); if (args.Length != 0) this.hostHandle = (IntPtr)int.Parse(args[0]); } private void btnSubmit_Click(object sender, EventArgs e) { this.person.Name = txtName.Text; int age; this.person.Age = int.TryParse(txtAge.Text, out age) ? age : 0; this.person.AddChildren(); if (this.hostHandle != IntPtr.Zero) { string data = GetPersionStr(); COPYDATASTRUCT cds = new COPYDATASTRUCT(); cds.dwData = (IntPtr)901; cds.cbData = data.Length + 1; cds.lpData = data; SendMessage(this.hostHandle, WM_COPYDATA, 0, ref cds); } } private string GetPersionStr() { return JsonConvert.SerializeObject(this.person); } }
这样在窗体按钮btnSubmit_Click事件中,完成了数据向HostApp的字符串形式传递。
如何获取宿主程序的窗口句柄呢?改造下ChildApp的Program.cs过程即可:
/// <summary> /// 应用程序的主入口点。 /// </summary> [STAThread] static void Main(string[] args) { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); Application.Run(new ChildForm(args)); }
3、HostApp项目
我们权且称之为宿主项目吧,其窗体代码为:
public partial class MainForm : Form { public const int WM_COPYDATA = 0x004A; public MainForm() { InitializeComponent(); } protected override void WndProc(ref Message m) { base.WndProc(ref m); switch (m.Msg) { case WM_COPYDATA: COPYDATASTRUCT copyData = new COPYDATASTRUCT(); Type type = copyData.GetType(); copyData = (COPYDATASTRUCT)m.GetLParam(type); string data = copyData.lpData; RestorePerson(data); break; } } private void RestorePerson(string data) { var person = JsonConvert.DeserializeObject<Person>(data); if (person != null) txtInfo.Text = person.ToString(); } private void btnSubmit_Click(object sender, EventArgs e) { RunChildProcess(); } private void RunChildProcess() { string appPath = Path.GetDirectoryName(Application.ExecutablePath); string childPath = Path.Combine(appPath, "ChildApp.exe"); Process.Start(childPath, this.Handle.ToString()); } }
它的作用就是接收子进程传递回来的字串,用JsonConvert反序列化为Person对象。
是不是很简单呢?
其实就是用了WM_COPYDATA的字符串传递功能,加上Json的序列化、反序列化,而实现c#不同进程间的对象传递
4、效果图:
5、2017-03-24追加:
今天又发现用Json序列化较为复杂的字串时,出现转义错误,导致反序列化失败。于时改用二进制序列化,转其为base64字串进行传递,问题解决。
代码如下:
public static class SerializeHelper { /// <summary> /// 序列obj对象为base64字串 /// </summary> /// <param name="obj"></param> /// <returns></returns> public static string Serialize(object obj) { if (obj == null) return string.Empty; try { var formatter = new BinaryFormatter(); var stream = new MemoryStream(); formatter.Serialize(stream, obj); stream.Position = 0; byte[] buffer = new byte[stream.Length]; stream.Read(buffer, 0, buffer.Length); stream.Close(); return Convert.ToBase64String(buffer); } catch (Exception ex) { throw new Exception(string.Format("序列化{0}失败,原因:{1}", obj, ex.Message)); } } /// <summary> /// 反序列化字符串到对象 /// </summary> /// <param name="str">要转换为对象的字符串</param> /// <returns>反序列化出来的对象</returns> public static T Deserialize<T>(string str) { var obj = default(T); if (string.IsNullOrEmpty(str)) return obj; try { var formatter = new BinaryFormatter(); byte[] buffer = Convert.FromBase64String(str); MemoryStream stream = new MemoryStream(buffer); obj = (T)formatter.Deserialize(stream); stream.Close(); } catch (Exception ex) { throw new Exception(string.Format("序列化{0}失败,原因:{1}", obj, ex.Message)); } return obj; } }
以上就是本文的全部内容,希望本文的内容对大家的学习或者工作能带来一定的帮助,同时也希望多多支持脚本之家!