Xamarin/C#中的Android FileObserver示例？

Question

我需要在Xamarin c#(Android)中创建文件观察器的指导

某种可行的例子会很精彩!

我试图将java转换为C#,但由于我在C#环境中缺乏经验,它在编译时会抛出太多错误..并且在C#和java中获取写入引用代码会让人感到恼火.

那么请!可能有人在那里指出我某种可行的方法

这是文件观察者https://gist.github.com/shirou/659180的java示例

Answer 1

创建一个继承自的类Android.OS.FileObserver,您只需要实现OnEvent()一个(+)构造函数.你看到它之后它是一个非常简单的模式... ;-)

笔记:

• 在路径上观察,如果需要按文件过滤,请在OnEvent中进行
• 不要让你的FileObserver对象得到GC,否则你的OnEvents会神奇地停止: - /
• 记得调用StartWatching()以接收OnEvent调用

FileObserver类:

using System;
using Android.OS;
using Android.Util;

namespace MyFileObserver
{
    public class MyPathObserver : Android.OS.FileObserver
    {
        static FileObserverEvents _Events = (FileObserverEvents.AllEvents);
        const string tag = "StackoverFlow";

        public MyPathObserver (String rootPath) : base(rootPath, _Events)
        {
            Log.Info(tag, String.Format("Watching : {0}", rootPath)); 
        }

        public MyPathObserver (String rootPath, FileObserverEvents events) : base(rootPath, events)
        {
            Log.Info(tag, String.Format("Watching : {0} : {1}", rootPath, events)); 
        }

        public override void OnEvent(FileObserverEvents e, String path)
        {
            Log.Info(tag, String.Format("{0}:{1}",path, e)); 
        }
    }
}

用法示例:

var pathToWatch = System.Environment.GetFolderPath (System.Environment.SpecialFolder.Personal);
// Do not let myFileObserver get GC'd, stash it's ref in an activty, or ...
myFileObserver = new MyPathObserver (pathToWatch);
myFileObserver.StartWatching (); // and StopWatching () when you are done...
var document = Path.Combine(pathToWatch, "StackOverFlow.txt");
button.Click += delegate {
    if (File.Exists (document)) {
        button.Text = "Delete File";
        File.Delete (document);
    } else {
        button.Text = "Create File";
        File.WriteAllText (document, "Foobar");
    }
};

adb logcat输出(单击测试按钮时):

I/StackoverFlow( 3596): StackOverFlow.txt:Create
I/StackoverFlow( 3596): StackOverFlow.txt:Open
I/StackoverFlow( 3596): StackOverFlow.txt:Modify
I/StackoverFlow( 3596): StackOverFlow.txt:CloseWrite
I/StackoverFlow( 3596): StackOverFlow.txt:Delete
I/StackoverFlow( 3596): StackOverFlow.txt:Create
I/StackoverFlow( 3596): StackOverFlow.txt:Open
I/StackoverFlow( 3596): StackOverFlow.txt:Modify
I/StackoverFlow( 3596): StackOverFlow.txt:CloseWrite
I/StackoverFlow( 3596): StackOverFlow.txt:Delete
I/StackoverFlow( 3596): StackOverFlow.txt:Create
I/StackoverFlow( 3596): StackOverFlow.txt:Open
I/StackoverFlow( 3596): StackOverFlow.txt:Modify
I/StackoverFlow( 3596): StackOverFlow.txt:CloseWrite