ObjC-Memory Management: Difference between revisions

ObjC-Memory Management (view source)

1,238 bytes added , 18 February 2010

m

emailconfirmed, nsInternRO, nsInternRW, Administrators

3,356

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@@ Line 23: / Line 23: @@
 == Beispiel ==
+=== Interface (file.h) ===
+<source lang="objc">
+@interface MyClass:NSObject {
+    NSString *name;
+    int age;
+    id delegate;
+}
+@property (nonatomic, retain) id delegate;
+// Hinweis: name und age würden normalerweise auch einfacher als properties verwendet!
+-(NSString*)name;
+-(void)setNewName:(NSString*)newName;
+-(int)age;
+-(void)setAge:(int)newAge;
+@end
+</source>
+=== Implementation (file.m) ===
+<source lang="objc">
+#import "file.h"
+@implementation MyClass
+@synthesize delegate;
+-(id)init {
+    self = [super init];
+    if(self) {
+        [self setName:@"Barnie"];
+        [self setAge:30];
+    }
+}
+-(NSString*)name { return name; }
+-(void)setName:(NSString*)newName {
+    if(newName != name) {
+        [name release];
+        [newName retain];
+        name = newName;
+    }
+}
+-(int)age { return age; }
+-(void)setAge:(int)newAge { age = newAge; }
+-(void)dealloc {
+    [delegate release]; // retain-property!
+    [self setName:nil]; // release wird im Setter gesendet!
+    // age braucht keinen release weil int ist kein Objekt!
+}
+@end
+</source>
+Fragen:
+* was ist ein Accessor?
+* was passiert im dealloc bei: <tt>name = nil;</tt>?
+* wo ist der Unterschied:
+** [self setName:nil];
+** self.name = nil;
+** name = nil;
 == Regeln ==