Creating and/or Removing a Login Item(添加/移除登陆项)

原文地址：http://cocoatutorial.grapewave.com/2010/02/creating-andor-removing-a-login-item/

Creating and/or Removing a Login Item

(创建或者移除登陆项)

Hi all,

Today, we will look at how to programmatically add an application to the Login Items. We will also look at removing it from the Login Items.

(如何以编程的方式添加应用程序到登录项，以及移除登录项)

Pre-requirements

We are going to be using the LaunchServices/LSSharedFileList.h to modify the list of login items. This is only available in OS X 10.5 and above. To support systems less than 10.5, you would have to use Apple Events. This will not be covered in this post.

(将会使用 LaunchServices/LSSharedFileList.h来修改登录项列表，只适用于10.5及以上的系统，如果要支持10.5以前的，就需要用到Apple Events，此文不包括)

Methods

There are basically four methods we will have to use to add/remove a LoginItem. One will retrieve the list of LoginItems, the second will add a new item to that list, the third will remove an item from the list and that one is used to resolve the LoginItem with an URL.

(有四种方法来添加或者移除登录项

1：获取登录项列表

2：添加一个登录项

3：从登录列表中移除一项

4：添加一个指向URL的登录项)

The following method will retrieve the list of existing LoginItems

(1:获取登录列表)

extern LSSharedFileListRef

  LSSharedFileListCreate(

  CFAllocatorRef   inAllocator,

  CFStringRef      inListType,

  CFTypeRef        listOptions)

(参数的解释就不介绍了)

Parameters:

1. inAllocator - CFAllocatorRef used to allocate the LSSharedFileListRef . NULL means default allocator.
2. inListType - A constant indicating list type to create (in our case, it will be kLSSharedFileListSessionLoginItems or
   kLSSharedFileListGlobalLoginItems).
3. listOptions – Other options. This is generally NULL.

The second that we are going to look at will insert a new Login Item into the list, if it already does not exist. If it already exists, it will just move the item to the particular location in the list specified by the insertAfterThisItem parameter

(2:插入一个登录项，如果该项已经存在，那它将会移动insertAfterThisItem这个列表中)

extern LSSharedFileListItemRef

  LSSharedFileListInsertItemURL(

  LSSharedFileListRef       inList,

  LSSharedFileListItemRef   insertAfterThisItem,

  CFStringRef               inDisplayName,

  IconRef                   inIconRef,

  CFURLRef                  inURL,

  CFDictionaryRef           inPropertiesToSet,

  CFArrayRef                inPropertiesToClear)

Parameters:

1. inList – The list to which we want to add a new Login Item.
2. insertAfterThisItem - Item after which new item has to be inserted. To insert at the beginning of
   the list use kLSSharedFileListItemBeforeFirst or to insert at the end of the list use kLSSharedFileListItemLast.
3. inDisplayName – Display name of the new item. Can be NULL. If NULL, it will use the application’s name.
4. inIconRef – Icon of the new item. Can be NULL. If NULL, it will use the default application icon.
5. inURL – URL of the new item. This will be the full path where the .app is found(includes dummy.app).

The other two parameters are not that important at this point of time and they can be NULL.

The third method will allow the application to be removed from the list of Login Items.

(3:移除登录项从登录列表中)

extern OSStatus

  LSSharedFileListItemRemove(

  LSSharedFileListRef       inList,

  LSSharedFileListItemRef   inItem)

Parameters:

1. inList – The list from which the item will be removed.
2. inItem – The item to be removed

The last method is used to resolve the LoginItem with an URL when we are searching through the list of Login Items.

(4:根据URL获取登录项)

extern OSStatus

LSSharedFileListItemResolve(

LSSharedFileListItemRef   inItem,

UInt32                    inFlags,

CFURLRef *                outURL,

FSRef *                   outRef)

Parameters:

1. inItem – The item we are trying to resolve.
2. inFlags – This is generally NULL.
3. outURL – The URL to which we are trying to resolve the item to.
4. outRef – FSRef of original item. Can be NULL.

Implementation

For this example, I have created two methods. The first method will add your application to the login item and the second will remove the application from the list of Login Items.

(代码就不用说了吧，都能看得懂)

-(void) addAppAsLoginItem{

NSString * appPath = [[NSBundle mainBundle] bundlePath];

// This will retrieve the path for the application

// For example, /Applications/test.app

CFURLRef url = (CFURLRef)[NSURL fileURLWithPath:appPath]; 

// Create a reference to the shared file list.

        // We are adding it to the current user only.

        // If we want to add it all users, use

        // kLSSharedFileListGlobalLoginItems instead of 

        //kLSSharedFileListSessionLoginItems

LSSharedFileListRef loginItems = LSSharedFileListCreate(NULL,

                                                     kLSSharedFileListSessionLoginItems, NULL);

if (loginItems) {

//Insert an item to the list.

LSSharedFileListItemRef item = LSSharedFileListInsertItemURL(loginItems,

                                                     kLSSharedFileListItemLast, NULL, NULL,

                                                     url, NULL, NULL);

if (item){

CFRelease(item);

                }

}

CFRelease(loginItems);

}

-(void) deleteAppFromLoginItem{

NSString * appPath = [[NSBundle mainBundle] bundlePath];

// This will retrieve the path for the application

// For example, /Applications/test.app

CFURLRef url = (CFURLRef)[NSURL fileURLWithPath:appPath]; 

// Create a reference to the shared file list.

LSSharedFileListRef loginItems = LSSharedFileListCreate(NULL,

                                               kLSSharedFileListSessionLoginItems, NULL);

if (loginItems) {

UInt32 seedValue;

//Retrieve the list of Login Items and cast them to

// a NSArray so that it will be easier to iterate.

NSArray  *loginItemsArray = (NSArray *)LSSharedFileListCopySnapshot(loginItems, &seedValue);

int i = 0;

for(i ; i< [loginItemsArray count]; i++){

LSSharedFileListItemRef itemRef = (LSSharedFileListItemRef)[loginItemsArray

                                                                               objectAtIndex:i];

//Resolve the item with URL

if (LSSharedFileListItemResolve(itemRef, 0, (CFURLRef*) &url, NULL) == noErr) {

NSString * urlPath = [(NSURL*)url path];

if ([urlPath compare:appPath] == NSOrderedSame){

LSSharedFileListItemRemove(loginItems,itemRef);

}

}

}

[loginItemsArray release];

}

}

That is it. You can basically have a preference that asks the user whether he wants the app to open at login. Depending on the answer, you can invoke one of the method.

Good Luck.

(以上就搞定，你可以询问用户是否想要设置当前应用为登录项，然后根据用户的选择来定)