Iphone 内存泄漏-从包含自定义对象的类方法返回NSMutableArray
我正在使用DBManager类从SQlite数据库重新运行数据。该类包含通过从数据库获取来返回MutableArray的方法。像贝娄一样Iphone 内存泄漏-从包含自定义对象的类方法返回NSMutableArray,iphone,ipad,memory-management,memory-leaks,Iphone,Ipad,Memory Management,Memory Leaks,我正在使用DBManager类从SQlite数据库重新运行数据。该类包含通过从数据库获取来返回MutableArray的方法。像贝娄一样 + (NSMutableArray *) getSaleForYear : (NSString *) year { if ([DBManager openDBConnection]) { NSMutableArray * sales = [[NSMutableArray alloc] initWithCapacity:1];
+ (NSMutableArray *) getSaleForYear : (NSString *) year {
if ([DBManager openDBConnection]) {
NSMutableArray * sales = [[NSMutableArray alloc] initWithCapacity:1];
const char *q = "SELECT sales, quarter FROM sale where year like ? order by quarter";
sqlite3_stmt *selectstmt;
if (sqlite3_prepare_v2(database, q, -1, &selectstmt, NULL) == SQLITE_OK) {
if(sqlite3_bind_text(selectstmt, 1, [year UTF8String] , -1, SQLITE_TRANSIENT) != SQLITE_OK){
NSLog(@"bind error : %@", [NSString stringWithUTF8String: sqlite3_errmsg(database)]);
return nil;
}
while(sqlite3_step(selectstmt) == SQLITE_ROW) {
float sale = sqlite3_column_double(selectstmt, 0);
//NSString * quarter = [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectstmt, 1)];
NSString * quarter = [[NSString alloc] initWithUTF8String:(char *)sqlite3_column_text(selectstmt, 1)];
ChartData * b1 = [[ChartData alloc] initwithdata:quarter y:sale];
[sales addObject:b1];
[b1 release];
[quarter release];
}
}
sqlite3_finalize(selectstmt);
[DBManager closeDBConnection];
return [sales autorelease];
}else {
return nil;
}
}
我像这样调用这个方法
- (IBAction) getData {
NSLog(@"getdata");
if (arr != nil) {
for (ChartData * cd in arr) {
[cd release];
}
arr = nil;
[arr release];
}
arr = [[DBManager getSaleForYear:@"2010-11"] copy];
NSLog(@"count %d ", [arr count]);
}
这种方法为函数的迭代调用创建内存泄漏。
请说明泄漏原因和解决方法。您可能应该颠倒这些代码行:
arr = nil;
[arr release];
这样:
[arr release];
arr = nil;
arr=nil
,该[arr release]
无效- (IBAction)getData {
NSLog(@"getdata");
[arr release];
arr = [[DBManager getSaleForYear:@"2010-11"] copy];
NSLog(@"count %d ", [arr count]);
}
第二点应该是“你不能循环…”。当外部数组被释放时,每个对象都将从数组中移除,并将获得另一个释放调用。但它已经手动发布了。->内存例外,我添加的那个循环只是为了测试它是否能解决我的问题。因为我无法看到仅为
[arr release]