客觀c內存泄漏

Question

這裏有兩個方法返回我的自定義四元對象的字典。他們將字符串，浮點數和BOOL數組放入Chemical對象中，然後從數組中構建字典。我對整個內存管理遊戲已經足夠新穎了，以至於當我擁有某些東西以及何時發佈它時，我並不總是很確定。我正在製作各種各樣的字符串。

事情是這樣的：靜態分析認爲沒有問題與第一種方法，- (id)generateChlorineDictionary但是他說，有一個在第二個，- (id)generateCYADictionary泄漏。它表示它從NSMutableArray *cyaGranulesArray...開始，然後進入NSDictionary *cyaDictionary...，最後到return cyaDictionary聲明。

以下是兩種方法;對不起，他們太久了！

---

編輯：更名從generateChlorineDictionary到newChlorineDictionary
刪除釋放返回

- (id)newChlorineDictionary { 
// Sets up the array for the Bleach key 
    NSMutableArray *bleachArray = [[NSMutableArray alloc] init]; 
    NSArray *bleachConcentrationArray = [[NSArray alloc] initWithObjects:@"6%", @"10%", @"12%", nil]; 
    float bleachConstantArray[] = {0.0021400, 0.0012840, 0.0010700}; 
    for (int i=0; i<3; i++) { 
     Chemical *bleachChemical = [[Chemical alloc] initWithChemical:@"Bleach" 
               andConcentration:[bleachConcentrationArray objectAtIndex:i] 
                andConstant:bleachConstantArray[i] 
                andIsLiquid:YES]; 
     [bleachArray addObject:bleachChemical]; 
     NSLog(@"bleachChemical: chemName = %@, chemConcentration = %@, chemConstant = %1.6f, chemIsLiquid = %d", bleachChemical.chemName, bleachChemical.chemConcentration, bleachChemical.chemConstant, bleachChemical.chemIsLiquid); 
     [bleachChemical release]; 
    } 
    bleachConcentrationArray = nil; 
// Sets up the array for the Trichlor key 
    NSMutableArray *trichlorArray = [[NSMutableArray alloc] init]; 
    Chemical *trichlorChemical = [[Chemical alloc] initWithChemical:@"Trichlor" 
              andConcentration:@"90%" 
               andConstant:0.0001480 
               andIsLiquid:NO]; 
    [trichlorArray addObject:trichlorChemical]; 
    NSLog(@"trichlorChemical: chemName = %@, chemConcentration = %@, chemConstant = %1.6f, chemIsLiquid = %d", trichlorChemical.chemName, trichlorChemical.chemConcentration, trichlorChemical.chemConstant, trichlorChemical.chemIsLiquid); 
    [trichlorChemical release]; 
// Sets up the array for the Dichlor key 
    NSMutableArray *dichlorArray = [[NSMutableArray alloc] init]; 
    NSArray *dichlorConcentrationArray = [[NSArray alloc] initWithObjects:@"56%", @"62%", nil]; 
    float dichlorConstantArray[] = {0.0002400, 0.0002168}; 
    for (int i=0; i<2; i++) { 
     Chemical *dichlorChemical = [[Chemical alloc] initWithChemical:@"Dichlor" 
               andConcentration:[dichlorConcentrationArray objectAtIndex:i] 
                andConstant:dichlorConstantArray[i] 
                andIsLiquid:NO]; 
     [dichlorArray addObject:dichlorChemical]; 
     NSLog(@"dichlorChemical: chemName = %@, chemConcentration = %@, chemConstant = %1.6f, chemIsLiquid = %d", dichlorChemical.chemName, dichlorChemical.chemConcentration, dichlorChemical.chemConstant, dichlorChemical.chemIsLiquid); 
     [dichlorChemical release]; 
    } 
    dichlorConcentrationArray = nil; 
// Sets up the array for the Cal Hypo key 
    NSMutableArray *calHypoArray = [[NSMutableArray alloc] init]; 
    NSArray *calHypoConcentrationArray = [[NSArray alloc] initWithObjects:@"48%", @"53%", @"65", @"73", nil]; 
    float calHypoConstantArray[] = {0.0002817, 0.0002551, 0.0002080, 0.0001852}; 
    for (int i=0; i<2; i++) { 
     Chemical *calHypoChemical = [[Chemical alloc] initWithChemical:@"Cal Hypo" 
               andConcentration:[calHypoConcentrationArray objectAtIndex:i] 
                andConstant:calHypoConstantArray[i] 
                andIsLiquid:NO]; 
     [calHypoArray addObject:calHypoChemical]; 
     NSLog(@"calHypoChemical: chemName = %@, chemConcentration = %@, chemConstant = %1.6f, chemIsLiquid = %d", calHypoChemical.chemName, calHypoChemical.chemConcentration, calHypoChemical.chemConstant, calHypoChemical.chemIsLiquid); 
     [calHypoChemical release]; 
    } 
    calHypoConcentrationArray = nil; 
// Sets up the array for the Li Hypo key  
    NSMutableArray *liHypoArray = [[NSMutableArray alloc] init]; 
    Chemical *liHypoChemical = [[Chemical alloc] initWithChemical:@"Li Hypo" 
              andConcentration:@"90%" 
               andConstant:0.0003800 
               andIsLiquid:NO]; 
    [liHypoArray addObject:liHypoChemical]; 
    NSLog(@"liHypoChemical: chemName = %@, chemConcentration = %@, chemConstant = %1.6f, chemIsLiquid = %d", liHypoChemical.chemName, liHypoChemical.chemConcentration, liHypoChemical.chemConstant, liHypoChemical.chemIsLiquid); 
    [liHypoChemical release]; 
// The array of keys for the chlorine chemicals 
    NSArray *chlorineKeys = [[NSArray alloc] initWithObjects:@"Bleach", @"Trichlor", @"Dichlor", @"Cal Hypo", @"Li Hypo", nil]; 
// The array of values for the chlorine chemicals 
    NSArray *chlorineValues = [[NSArray alloc] initWithObjects:bleachArray, trichlorArray, dichlorArray, calHypoArray, liHypoArray, nil]; 
    [bleachArray release]; 
    [trichlorArray release]; 
    [dichlorArray release]; 
    [calHypoArray release]; 
    [liHypoArray release]; 
// The dictionary to hold the arrays of chlorine chemical objects 
    NSDictionary *chlorineDictionary = [[NSDictionary alloc] initWithObjects:chlorineValues forKeys:chlorineKeys]; 
    [chlorineValues release]; 
    [chlorineKeys release]; 
    return chlorineDictionary; 
} 

---

編輯之後發生：從generateCYADictionary到newCYADictionary
更名刪除釋放所發生返回後

- (id)newCYADictionary { 
    // Sets up the array for the CYA Granules key 
    NSMutableArray *cyaGranulesArray = [[NSMutableArray alloc] init]; 
    Chemical *cyaGranulesChemical = [[Chemical alloc] initWithChemical:@"CYA Granules" 
                andConcentration:@"" 
                 andConstant:0.0001330 
                 andIsLiquid:NO]; 
    [cyaGranulesArray addObject:cyaGranulesChemical]; 
    NSLog(@"cyaGranulesChemical: chemName = %@, chemConcentration = %@, chemConstant = %1.6f, chemIsLiquid = %d", cyaGranulesChemical.chemName, cyaGranulesChemical.chemConcentration, cyaGranulesChemical.chemConstant, cyaGranulesChemical.chemIsLiquid); 
    [cyaGranulesChemical release]; 
    // Sets up the array for the Liquid Stabilizer key 
    NSMutableArray *liquidStabilizerArray = [[NSMutableArray alloc] init]; 
    Chemical *liquidStabilizerChemical = [[Chemical alloc] initWithChemical:@"Liquid Stabilizer" 
               andConcentration:@"" 
                 andConstant:0.0003460 
                 andIsLiquid:YES]; 
    [liquidStabilizerArray addObject:liquidStabilizerChemical]; 
    NSLog(@"liquidStabilizerChemical: chemName = %@, chemConcentration = %@, chemConstant = %1.6f, chemIsLiquid = %d", liquidStabilizerChemical.chemName, liquidStabilizerChemical.chemConcentration, liquidStabilizerChemical.chemConstant, liquidStabilizerChemical.chemIsLiquid); 
    [liquidStabilizerChemical release]; 
    // The array of keys for the CYA chemicals 
    NSArray *cyaKeys = [[NSArray alloc] initWithObjects:@"CYA Granules", @"Liquid Stabilizer", nil]; 
    // The array of values for the CYA chemicals 
    NSArray *cyaValues = [[NSArray alloc] initWithObjects:cyaGranulesArray, liquidStabilizerArray, nil]; 
    [cyaGranulesArray release]; 
    [liquidStabilizerArray release]; 
    // The dictionary to hold the arrays of CYA chemical objects 
    NSDictionary *cyaDictionary = [[NSDictionary alloc] initWithObjects:cyaValues forKeys:cyaKeys]; 
    [cyaKeys release]; 
    [cyaValues release]; 
    return cyaDictionary; 
} 

Answer 1

更換

return cyaDictionary; 
[cyaDictionary release]; 

隨着

return [cyaDictionary autorelease]; 

或者，你可以更換

NSDictionary *chlorineDictionary = [[NSDictionary alloc] initWithObjects:chlorineValues forKeys:chlorineKeys]; 

隨着

NSDictionary *chlorineDictionary = [NSDictionary dictionaryWithObjects:chlorineValues forKeys:chlorineKeys]; 

而不是添加autorelease。

在你原來實行的[cyaDictionary release];永遠不會執行（因爲它是return後）。

您可以在此方法之外使用此字典，但不應將其釋放。

您可能還想返回一個保留的對象（沒有autorelease）並將其釋放到方法外部。在這種情況下，你應該用「新」或「黃金」 ......

EDIT（重要）啓動方法名稱：
你應該只使用我的建議之一。

• 使用autorelease在return線
• 使用dictionaryWith...
• 添加「新」或「黃金」前綴的方法名和釋放這種方法外返回的對象。

如果您將alloc init替換爲dictionaryWith...，則會得到一個自動釋放對象。然後，如果你在外部方法中釋放它，那麼你有一個嚴重的問題（對象將在當前線程的runloop之後嘗試釋放它自己，並且可能會導致應用程序崩潰，因爲對象已經被你釋放）。

EDIT（由於一個評論）
如果你想創建一個將返回字典的屬性：

// MyClass.h file 
@interface MyClass : NSObject { 

    .. 

    NSDictionary *_dict1; 

    .. 

} 

@property (nonatomic, retain) NSDictionary *dict1; 

.. 

@end 

// MyClass.m file 

@implementation MyClass 

@synthesize dict1 = _dict1; 

.. 

- (NSDictionary *)dict1 { 
    if (_dict1 == nil) { 
     NSDictionary *dict1Temp = [NSDictionary new]; 

     // Your implementation goes here... 

     self.dict1 = dict1Temp; 
     [dict1Temp release]; 
    } 
} 

.. 

- (void)dealloc { 
    [_dict1 release]; 
    [suoer dealloc]; 
} 

@end