看了(ji¨£n)下官æ–ÒŽ(gu¨©)–‡æ¡£çš„关于object c 的内å˜ç®¡ç?æ€È»“ä¸?
在iphoneä¸object c ä¸çš„内嘽Ž¡ç†æ˜¯é€šè¿‡è®¡æ•°å™¨æ¥½Ž¡ç†çš?æ¯ä¸ªå¯¹è±¡å†…部都有一个计数器.æ–°å¾ä¸€ä¸ªå¯¹è±?或者这个对象被其他对象引用,多会(x¨¬)使计数器åŠ?.Retain å¢žåŠ è®¡æ•°å™¨å€?/span>release å‡å°‘计数器å€?当计数器ä¸?时对象就dealloc自己.
在object cä¸ä½ 生æˆçš„ä¸€ä¸ªå¯¹è±¡é‚£ä¹ˆä½ ž®±æœ‰è´£ä“Q去释攑֮ƒåQŒå†…å˜ç®¡ç†çš„一般规则：(x¨¬)
-
You own any object you create by allocating memory for it or copying it.
Related methods:alloc,allocWithZone:,copy,copyWithZone:,mutableCopy,mutableCopyWithZone:
-
If you are not the creator of an
object, but want to ensure it stays in memory for you to use, you can
express an ownership interest in it.
Related method:retain
-
If you own an object, either by
creating it or expressing an ownership interest, you are responsible for
releasing it when you no longer need it.
Related methods:release,autorelease
-
Conversely, if you are not the creator of an object and have not expressed an ownership interest, you mustnotrelease it.
You own any object you create by allocating memory for it or copying it.
Related methods:alloc,allocWithZone:,copy,copyWithZone:,mutableCopy,mutableCopyWithZone:
If you are not the creator of an object, but want to ensure it stays in memory for you to use, you can express an ownership interest in it.
Related method:retain
If you own an object, either by creating it or expressing an ownership interest, you are responsible for releasing it when you no longer need it.
Related methods:release,autorelease
Conversely, if you are not the creator of an object and have not expressed an ownership interest, you mustnotrelease it.
考虑下题q™ä¸ªä¾‹ååQ?/div>
Thingamajig *thingamajig = [[Thingamajig alloc] init];
NSArray *sprockets = [thingamajig sprockets];
[thingamajig release];
thingamajig 需è¦releaseåQŒå› 为很昄¡„¶˜q™é‡Œæˆ‘们æ˜?span style="font-family: 'Courier New';">thingamajigçš„owner。（½W¬ä¸€æ¡è§„则）(j¨ª)
那么sprocketsä¸ÞZ»€ä¹ˆä¸éœ€è¦?span style="font-family: 'Courier New';">releaseå‘¢ã€?br />
首先我们ä¸æ˜¯sprocketsçš?creater.åQˆç¬¬ä¸€æ¡è§„则）(j¨ª),我们也没有expressing an ownership intereståQŒå› 为我们没æœ?/span>
retain它，åQˆç¬¬äºŒæ¡è§„则åQ?所以我们ä¸è´Ÿè´£release它ã€?/span>
具体æ¥çœ‹thingamajigçš?span style="font-family: 'Courier New';">sprocketsæ–ÒŽ(gu¨©)³•çš„实玎ͼš(x¨¬)
retain它，åQˆç¬¬äºŒæ¡è§„则åQ?所以我们ä¸è´Ÿè´£release它ã€?/span>
具体æ¥çœ‹thingamajigçš?span style="font-family: 'Courier New';">sprocketsæ–ÒŽ(gu¨©)³•çš„实玎ͼš(x¨¬)
(NSArray *)sprockets {
NSArray *array;
array = [[NSArray alloc] initWithObjects:mainSprocket,auxiliarySprocket, nil];
return [array autorelease];
}
array = [[NSArray alloc] initWithObjects:mainSprocket,auxiliarySprocket, nil];
return [array autorelease];
}
å¯è§åˆ†é…的内å˜åœ¨æ–ÒŽ(gu¨©)³•é‡Œå°±å·²ç»ç”?span style="font-family: 'Courier New';">autorelease释放äº?ji¨£n)，åªä¸˜q‡æ˜¯½EåŽé‡Šæ”¾ã€‚å‚è§autorelease poolã€?/span>
˜q™é‡Œæœ‰ä¸ªå¾ˆé‡è¦çš„原则åQ?/strong>
Becausethe classcreates the new object,itis responsible for disposing of the new object.
˜q™ä¸ªå¯¹è±¡åœ¨å“ªé‡Œç”Ÿæˆçš„åQŒå°±åº”该在哪里释放ã€?/strong>
æ‰€ä»¥ä½ çœ‹åˆ°å¾ˆå¤š¾cÀLœ‰ä»¥è‡ªå·Þq±»åäØ“(f¨´)æ–ÒŽ(gu¨©)³•çš„æž„é€ å‡½æ•ŽÍ¼Œä½ 调用的时候就ä¸éœ€è¦release.å› äØ“(f¨´)åœ¨è¿™ä¸ªæž„é€ å‡½æ•îC¸å·²ç»å?/span>
˜q?/span>autoreleaseäº?ji¨£n)ã€?/span>
ä½ æ²¡æœ‰alloc˜q™ä¸ªå¯¹è±¡ž®×ƒ¸è´Ÿè´£releaseå®?/span>
现在æ¥çœ‹è§„则2åQŒæœ‰äº›æ—¶å€™æˆ‘们在自己的类里è¦å¼•ç”¨å…¶ä»–的对象，如把˜q™ä¸ªå…¶ä»–的对象å˜æˆè‡ªå·Þqš„æˆå‘˜å˜é‡ã€?/div>
那么ž®±æœ‰ä¸€ä¸ªé—®é¢˜ï¼Œ˜q™ä¸ªè¢«å¼•ç”¨çš„对象是å¦è¢«releaseä¸è¢«ä½ 控åˆÓž¼Œä¸€æ—¦å®ƒè¢«releaseåQŒä½ 自己的程åºå°±ä¼?x¨¬)出问é¢?/div>
˜q™æ—¶å€™æˆ‘们就需è¦retain˜q™ä¸ªå¯¹è±¡ã€‚表½CÞZ½ ˜q™ä¸ª¾cÖM¹Ÿæ‹¥æœ‰˜q™ä¸ªå¯¹è±¡åQŒåªæœ‰ä½ 自己的类releaseåŽï¼Œè¢«å¼•ç”¨çš„对象æ‰æœ‰å¯èƒ½è¢«release
一般的set æ–ÒŽ(gu¨©)³•åQ?/div>
@interface Counter : NSObject {
NSNumber *count;
}
}
- (void)setCount:(NSNumber *)newCount {
[newCount retain];
[count release];
count = newCount;
[count release];
count = newCount;
}
在setä¸æˆ‘ä»¬å¯¹ä¼ è¿›æ¥çš„对象˜q›è¡Œäº?ji¨£n)retain. ä¸ÞZ»€ä¹ˆè¦å…?span style="font-family: 'Courier New';">retainå?span style="font-family: 'Courier New';">releaseåQŒå› 为如æž?span style="font-family: 'Courier New';">newCountå’?span style="font-family: 'Courier New';">count是åŒä¸€ä¸ªå¯¹è±?/div>
å…ˆreleaseçš„è¯ä¼?x¨¬)导致这个对象delloc.
‹‚‹å‰‘ž®ç§‹ 2010-12-30 15:47 å‘表评论
]]>
Ö÷Õ¾Ö©Öë³ØÄ£°å£º
È«ÖÝÏØ|
¶î¶û¹ÅÄÉÊÐ|
¼ÃÄÏÊÐ|
è÷äüÏØ|
ƽÀÖÏØ|
ãÉÐÐÇø|
Ö¾µ¤ÏØ|
ÅìºþÏØ|
ºÚɽÏØ|
ÕżҸÛÊÐ|
ÀÉϪÏØ|
´¾°²ÏØ|
·ïɽÏØ|
ÇúÎÖÏØ|
ÓÀºÍÏØ|
»á¶«ÏØ|
°¢ºÏÆæÏØ|
ÎäÄþÏØ|
ͨ»¯ÊÐ|
´óÒ¦ÏØ|
ÁèÔÆÏØ|
ÏåÔ«ÏØ|
ÐÂÉÛÏØ|
¿ª·âÊÐ|
ÂÞ¶¨ÊÐ|
ÇåË®ÏØ|
µÂ°²ÏØ|
´ó¹ØÏØ|
¹ÌÔÊÐ|
Ö¾µ¤ÏØ|
ÇåÔ|
ÖÛÇúÏØ|
ÉÏ˼ÏØ|
ÓÀ´¨ÊÐ|
¸»´¨|
Ñ®ÒØÏØ|
¹ãÄÏÏØ|
ÙÙÖÝÊÐ|
ÒǤÏØ|
Õ´»¯ÏØ|
µ¤Õ¯ÏØ|