NSString內存泄漏

Question

我在從NSManagedObject構建電子郵件字符串的方法中遇到內存泄漏。 該字符串是使用NSString便捷方法創建的，因此應自動釋放。 我想念什么？ 下面的代碼...儀器正在標記buildString在該方法底部附近的最終出現（請參見代碼中的注釋）：

    -(void)buildEmailMessage {

    //check for presence of lat and lon data
    BOOL hasStartLatLon = NO;
    BOOL hasEndLanLon = NO;
    NSString *startLat;
    NSString *startLong;
    NSString *endLat;
    NSString *endLong;
    NSString *mapURL;
    NSString *finalMapURL;

    if( [managedObject valueForKey:@"startLat"] > 0 ){
        hasStartLatLon = YES;
        startLat = [self formatLatLon:[managedObject valueForKey:@"startLat"]];
        startLong= [self formatLatLon:[managedObject valueForKey:@"startLong"]];
    }

    if( [managedObject valueForKey:@"endLat"] > 0 ) {
        hasEndLanLon = YES;
        endLat = [self formatLatLon:[managedObject valueForKey:@"endLat"]];
        endLong= [self formatLatLon:[managedObject valueForKey:@"endLong"]];
    }

    // Build strings from managedObject
    // Start with the trip info already validated
    NSString *tripName = [managedObject valueForKey:@"tripName"];
    NSString *intro = [NSString stringWithString:@"
Please contact the approriate authorities and provide them with the enclosed information if our party does not return withing 12 hours of the return date shown below. Thanks.
"]; id vStartDate = [managedObject valueForKey:@"startDate"]; NSString *startDate = [NSString stringWithFormat:@"
Start Date: %@", [vStartDate managedObjectValueDisplay]]; id vEndDate = [managedObject valueForKey:@"endDate"]; NSString *endDate = [NSString stringWithFormat:@"
End Date: %@
", [vEndDate managedObjectValueDisplay]];

    NSString *startFrom = [NSString stringWithFormat:@"
Departing from:
%@", [managedObject valueForKey:@"startFrom"]]; if( hasStartLatLon ){ startFrom = [startFrom stringByAppendingString:@"
"]; startFrom = [startFrom stringByAppendingString:[self getLatLon:@"start"]]; } startFrom = [startFrom stringByAppendingString:@"
"];

    NSString *endAt = [NSString stringWithFormat:@"
Returning to:
%@", [managedObject valueForKey:@"endAt"]]; if( hasStartLatLon ){ endAt = [endAt stringByAppendingString:@"
"]; endAt = [endAt stringByAppendingString:[self getLatLon:@"end"]]; } endAt = [startFrom stringByAppendingString:@"
"];

    // Add a link to Google Maps if there is geodata
    if (hasStartLatLon || hasEndLanLon) {

        if (hasStartLatLon) {
            mapURL = [NSString stringWithFormat:@"http://maps.google.com/?q=%@,%@+(%@)&ll=%@,%@&z=14&t=p", startLat, startLong, [managedObject valueForKey:@"startFrom"], startLat, startLong];
        } else {
            mapURL = [NSString stringWithFormat:@"http://maps.google.com/?q=%@,%@+(%@)&ll=%@,%@&z=14&t=p", endLat, endLong, [managedObject valueForKey:@"endAt"], endLat, endLong];
        }

        NSString* escapedUrlString =[mapURL stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
        NSLog(@"escaped  map url = %@", escapedUrlString);
        finalMapURL = [NSString stringWithFormat:@"Link to Google Map:
%@", escapedUrlString];
    }

    NSString *routeInfo = [NSString stringWithFormat:@"
Route Information:
%@ 
", [managedObject valueForKey:@"routeInfo"]];

    // Check for vehicle info
    BOOL hasVehicleMakeAndModel = NO;
    BOOL hasVehicleLicenseNumber = NO;
    BOOL hasVehicleState = NO;

    NSString *vehicleMakeAndModel = [managedObject valueForKey:@"vehicleMakeAndModel"];
    NSString *vehicleLicenseNumber = [managedObject valueForKey:@"vehicleLicenseNumber"];
    NSString *vehicleState = [managedObject valueForKey:@"vehicleState"];

    if ( vehicleMakeAndModel.length > 0 ) {
        hasVehicleMakeAndModel = YES;
    }

    if ( vehicleLicenseNumber.length > 0 ) {
        hasVehicleLicenseNumber = YES;
    }

    if ( vehicleState.length > 0 ) {
        hasVehicleState = YES;
    }

    //Build the vehicle string
    NSString *vehicleString;

    if (hasVehicleMakeAndModel || hasVehicleLicenseNumber || hasVehicleState) {
        vehicleString = [NSString stringWithString:@"
Vehicle Information:
"]; } if (hasVehicleMakeAndModel) { vehicleString = [vehicleString stringByAppendingString:@"Make/Model: "]; vehicleString = [vehicleString stringByAppendingString:vehicleMakeAndModel]; vehicleString = [vehicleString stringByAppendingString:@"
"]; } if (hasVehicleLicenseNumber) { vehicleString = [vehicleString stringByAppendingString:@"License #: "]; vehicleString = [vehicleString stringByAppendingString:vehicleLicenseNumber]; vehicleString = [vehicleString stringByAppendingString:@"
"]; } if (hasVehicleState) { vehicleString = [vehicleString stringByAppendingString:@"State: "]; vehicleString = [vehicleString stringByAppendingString:vehicleState]; } // Get the NSSet of party members from the managedObject // and build the party members/emergency contact info NSSet *membersSet = [managedObject valueForKey:@"members"]; NSString *membersString; if ( [membersSet count] > 0) { membersString = @"
Party Members:
";

        NSArray *membersArray = [NSArray arrayByOrderingSet:membersSet byKey:@"lastName" ascending:YES];

        for (NSManagedObject *oneObject in membersArray) {

            BOOL hasFirstName = NO;
            BOOL hasLastName = NO;
            BOOL hasAge = NO;
            BOOL hasContactName = NO;
            BOOL hasContactNumber = NO;

            NSString *memberFirstName = [oneObject valueForKey:@"firstName"];
            NSString *memberLastName = [oneObject valueForKey:@"lastName"];

            NSNumber *memberAgeNum = [oneObject valueForKey:@"age"];
            NSString *memberAgeString;
            if (memberAgeNum > 0) {
                memberAgeString = [NSString stringWithFormat:@"%d", [memberAgeNum intValue]];
            } else {
                memberAgeString = [NSString stringWithString:@""];
            }

            NSString *contactName = [oneObject valueForKey:@"contactName"];
            NSString *contactNumber = [oneObject valueForKey:@"contactNumber"];

            if ( [memberFirstName length] > 0) {
                hasFirstName = YES;
            }

            if ( [memberLastName length] > 0) {
                hasLastName = YES;
            }

            if ( [memberAgeString length] > 0) {
                hasAge = YES;
            }

            if ( [contactName length] > 0) {
                hasContactName = YES;
            }

            if ( [contactNumber length] > 0) {
                hasContactNumber = YES;
            }

            NSString *oneMemberString = [NSString stringWithString:@"
"]; if (hasFirstName) { oneMemberString = [oneMemberString stringByAppendingFormat:@"%@ ", memberFirstName]; } if (hasLastName) { oneMemberString = [oneMemberString stringByAppendingString:memberLastName]; } if (hasAge) { oneMemberString = [oneMemberString stringByAppendingFormat:@", %@", memberAgeString]; } if (hasContactName) { oneMemberString = [oneMemberString stringByAppendingFormat:@"
Emergency Contact:
%@", contactName]; } if (hasContactNumber) { oneMemberString = [oneMemberString stringByAppendingFormat:@"
Phone: %@

", contactNumber];
            }

            membersString = [membersString stringByAppendingString:oneMemberString];
        }
    }


    NSString *buildString = [NSString stringWithFormat:@"
Trip Plan for:
%@
", tripName];
    buildString = [buildString stringByAppendingString: intro];
    buildString = [buildString stringByAppendingString: startDate];
    buildString = [buildString stringByAppendingString: endDate];
    buildString = [buildString stringByAppendingString: startFrom];
    buildString = [buildString stringByAppendingString: endAt];
    if (hasStartLatLon || hasEndLanLon) buildString = [buildString stringByAppendingString: finalMapURL];
    buildString = [buildString stringByAppendingString: routeInfo];
    // Append the vehicle string if any vehicle data is present
    if (hasVehicleMakeAndModel || hasVehicleLicenseNumber || hasVehicleState) {
        buildString = [buildString stringByAppendingString: vehicleString];
    }
    // Append the members string if any members data is present

        // **MEMORY LEAK** flagged on the line enclosed by the if statement below
    if ( [membersSet count] > 0)  {
        buildString = [buildString stringByAppendingString: membersString];
    }

    self.myEmailString = [NSString stringWithString:buildString];

}

-(NSString *)formatLatLon:(NSNumber *)value {
    NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
    [formatter setNumberStyle:NSNumberFormatterDecimalStyle];
    [formatter setPositiveFormat:@"##0.00000"];

    NSString *returnString = [formatter stringFromNumber:value];
    [formatter release];
    return returnString;
}

Answer 1

您如何myEmailString @property定義的？ 用copy還是retain ？ （您應該將copy與NSString對象一起使用。）如果是這樣，並且您沒有在dealloc執行[myEmailString release] ，則可能是泄漏。