在很多时候,写程序的时候需要很多的通知,事件 之类的东西,那么需要怎样应用呢?

简单举个例子,你写了一个类
class Work
{

      public void Start()
     {
           //....
     }
     public void Stop
     {
     }
}

那么如果这个类需要一些事件,例如,开始工作,停止工作
OnStart
OnStop
这些事件通知,那么可以用事件,和委托

加上
class Work
{
     public delegate void OnStartDelegate(object sender);
     public delegate void OnStopDelegate(object sender);

    public event OnStartDelegate OnStart;
    public event OnStopDelegate OnStop;

      public void Start()
     {
           //....
           if(OnStart!=null)
             OnStart(this);
     }
     public void Stop
     {

           if(OnStop!=null)
             OnStop(this);
     }
}

此时可以用

Work w=new Work();

w.OnStart += new OnStartDelegate(w_OnStart);

w.OnStop+= new OnStartDelegate(w_OnStop);

private void w_OnStart(object sender)

{

           //..........开始的时候处理

}

private void w_OnStop(object sender)

{

           //..........停止的时候处理

}

How to run BT3 Final within Windows, without rebooting, with persistent changes

As previously promised on another thread, here is the tutorial on how to get BT3 (Final or Beta) to work under Windows without rebooting, with persistent changes on the same FAT32 (or NTFS) "folder" using your HD or USB key.
1. Go to this site and follow ALL the instructions exactly as mentioned there. This will get you used to running Pen Drive Linux (PDL)
on your machine while on Windows. After you are familiar with this and got everything working (including Persistent changes),
then and only then proceed to Step #2.
http://www.pendrivelinux.com/2007/09...pendrivelinux/
EDIT: IMPORTANT:
-->
Once you boot into PDL with its GNOME, fire up a terminal (it should be under Accessories; root password is pendrivelinux), and type the following:
# cd /
# mkdir changes
# poweroff
Note: Don't save many changes, just test if the persistent changes work by changing the background for example, rebooting, and checking if its the same. Also make sure the changes directory you just created under / survived the reboot.
<--
2. Create a folder and name it BT3_within_windows. Place the following inside it from the previous PDL installation:
- The qemu folder and all its contents
- The LaunchPDL file
- the casper-rw.img file
and this from the BT3 image you downloaded:
- bt3-final.iso file (or bt3final_usb.iso if you want). Keep ONLY one .iso image at a time in the BT3_within_windows folder.
3. Rename the LaunchPDL file to LaunchBT3Final (or whatever you want)
4. Open LaunchBT3Final with notepad and make sure that the last line is as follow:
.\qemu\qemu -L .\qemu -kernel-kqemu -std-vga -localtime -soundhw all -m 512 -cdrom *.iso -hda casper-rw.img -boot d
5. Now you can place the BT3_within_windows folder on your current hard drive or on a USB key. For USB keys, you can actually put the BT3_within_windows folder anywhere, that is, you don't have to put it under the root partition of the USB key.
6. Double click on the LaunchBT3Final file. If running on another system, install qemu as it will ask you to do. If you don't have admin privileges, its OK, just hit cancel and proceed. It will still run, but slower.
7. If everything is OK, you should see a window popped out with the BT3 Final menu!!
8. Select the line "BT3 Graphics mode with Persistent Changes" and hit the Tab key. Make the following changes to the line:
- changes=/dev/hda1 (yes, its hda1 and NOT sda1, because, as far as BT3 is concerned, the "Drive", which in reality is the BT3 folder, is the first drive on this "virtual computer", therefore we will go with /dev/hda1.
- and for autoexec=xconf;kdm --> change that to: autoexec=kdm
9. Thats it! hit Enter and you be good to go. It should boot right into BT3 Final. On my computer, its very very fast, and persistent changes DO work.
10. THIS STEP IS OPTIONAL, but recommended OK, now we need to make some changes permanent to the iso image to avoid doing step 8 everytime we want to boot BT3 using this method.
These instructions were done using MagicISO in Windows:
a. Double click on the bt3final_usb.iso image, which would open MagicISO and you will find the boot and bt3 folders in the right panel.
b. Open the boot folder, then the isolinux folder. You should see 3 files there. Right click on isolinux.cfg and Extract it to your desktop.
c. Now, still under Magic ISO, right click on the same file (isolinux.cfg) and delete it.
d. On your desktop, open isolinux.cfg with Notepad or Wordpad. Look for the LABEL pchanges section and make the sure the last line of that section is exactly as follow:
APPEND vga=0x317 initrd=/boot/initrd.gz ramdisk_size=6666 root=/dev/ram0 rw changes=/dev/hda1 autoexec=kdm
Note: You can also cut and paste this section in place of the first section there, so that you can have it as the first line when you boot it from your HD or USB key:
PROMPT 0
TIMEOUT 40
DEFAULT /boot/vesamenu.c32
LABEL pchanges
MENU LABEL BT3 Graphics mode with Persistent Changes
KERNEL /boot/vmlinuz
APPEND vga=0x317 initrd=/boot/initrd.gz ramdisk_size=6666 root=/dev/ram0 rw changes=/dev/hda1 autoexec=kdm
... other sections ...
Note: you can also take out any section you dont want in order to make the boot menu simpler or with fewer entries..
Note: as long as we are using this method, its always going to be /dev/hda1.
Ok, now save the file and exit it.
e. Next, drag back the isolinux.cfg file to where it was in MagicISO. Then Select File and Save. Your iso image is now saved with the new changes.
f. Now simply move the new iso file to the BT3_within_windows folder and make sure that its the only iso there. After launching LaunchBT3Final, You should see your changes reflected on the BT3 boot menu.
Thats it! Feel free to ask any questions.
Enjoy!!
At this point, I do not believe you could mount any other HDs of your system using this method. Unless someone can prove otherwise.
Also, make sure you have enough RAM available.