我有自定义 mapView（我将其命名为 JMMapView，它继承自 UIView），我在 UIScrollView 中创建了 UIImageView。它做一些基本的事情，如缩放、滚动、添加精确点等等。但主要问题是它加载了一个存储在 Documents 文件夹中的图像（图像在运行时下载并永久存储在文档文件夹中）并占用大量内存。例如，所有图像都是从 100kb 到 800kb，但只加载一个图像内存是从 20mb 到 40mb。我做错了什么？为什么需要这么多内存？我使用ARC，图像都是PNG，大小为2000x2000。
数据控制器.m
+(NSData*) getDataOfUrlString:(NSString*)urlString {
NSString *fullLocalUrlString = [self formLocalDocumentsUrlWithPath:urlString];
NSString *remoteUrl;
NSData *data = [NSData dataWithContentsOfFile:fullLocalUrlString];
if (!data) {
NSString *remoteUrlString = [WSController formRequestURLWithMethod:urlString];
remoteUrl = remoteUrlString;
data = [NSData dataWithContentsOfURL:[NSURL URLWithString:remoteUrlString]];
if (data) {
[self createFoldersPathForFileWithFullUrlString:fullLocalUrlString];
[data writeToFile:fullLocalUrlString atomically:YES];
} else {
WLog([NSString stringWithFormat:@"data was not even downloaded from url:%@", remoteUrlString]);
}
}
if (!data) {
DLog(@"loaded data:%@, from urlString:%@", data ? @"YES" : @"NO", fullLocalUrlString);
DLog(@"Can't download from remote url:%@\n", remoteUrl);
}
return data;
}
MapPreviewViewController.m
//In background with @autoreleasepool
NSData* data = [DataController getDataOfUrlString:abstractUrl];
UIImage *image = nil;
if (data) {
DLog(@"returning map image with path:%@", abstractUrl);
image = [UIImage imageWithData:data];
}
//On Main thread
if (image && !mapView) {
mapView = [[JMMapView alloc] initWithImage:image fitSize:fitSize];
[mapView setViewController:self];
[self.view addSubview mapView];
}
JMMapView：UIView
#define KEY_BUTTON @"buttonKey"
#define KEY_COORDINATES @"coordinatesKey"
#define KEY_OBJECT @"jmObjectKey"
@interface JMMapView () {
UIImageView *mapView;
CGSize fitSize;
NSArray *pinpoints;
NSArray *directions;
UIScrollView *scrollView;
CGPoint pinchCenter;
NSDictionary *currentPoint;
NSDictionary *openPinpoint;
UIViewController *activeViewController;
FPPopoverController *popController;
}
@end
@implementation JMMapView
#pragma mark - initialization
-(id)initWithImage:(UIImage *)image fitSize:(CGSize)newSize {
self = [self initWithFrame:CGRectMake(0, NAVIGATION_BAR_HEIGHT - 44, newSize.width, newSize.height)];
if (self) {
[self initMapViewWithImage:image fitSize:newSize];
}
return self;
}
-(void) initMapViewWithImage:(UIImage*)mapImage fitSize:(CGSize)newFitSize {
mapView = [[UIImageView alloc] initWithImage:mapImage];
[self finishInitWithFitSize:newFitSize];
}
-(void) finishInitWithFitSize:(CGSize)newFitSize {
mapView.frame = [Utilities reframe:mapView.frame toFitSize:newFitSize];
CGRect scrollFrame = CGRectMake(0, 0, newFitSize.width, newFitSize.height);
scrollView = [[UIScrollView alloc] initWithFrame:scrollFrame];
[scrollView setContentSize:newFitSize];
[mapView setCenter:CGPointMake(scrollView.frame.size.width/2, scrollView.frame.size.height/2)];
[mapView setUserInteractionEnabled:YES];
[scrollView addSubview:mapView];
[self addSubview:scrollView];
fitSize = newFitSize;
[self initZooming];
}
//gesture recognizer
...
//
#pragma mark - private methods
//pinch handling
..
//
//Add pinpoint
-(void) addPinpointToArray:(UIButton*)pin position:(JMMapPosition *)position pinpointType:(PINPOINT_TYPE)pinType object:(id)object{
NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:
pin, KEY_BUTTON,
position, KEY_COORDINATES,
object, KEY_OBJECT,
nil];
switch (pinType) {
case PINPOINT_TYPE_CHILD_OBJECT:
{
if (!pinpoints) {
pinpoints = [[NSArray alloc] initWithObjects:dict, nil];
} else {
NSMutableArray *arrayM = [NSMutableArray arrayWithArray:pinpoints];
[arrayM addObject:dict];
pinpoints = [NSArray arrayWithArray:arrayM];
}
break;
}
case PINPOINT_TYPE_DIRECTION:
{
if (!directions) {
directions = [[NSArray alloc] initWithObjects:dict, nil];
} else {
NSMutableArray *arrayM = [NSMutableArray arrayWithArray:directions];
[arrayM addObject:dict];
directions = [NSArray arrayWithArray:arrayM];
}
break;
}
case PINPOINT_TYPE_OBJECT:
currentPoint = dict;
break;
default:
break;
}
}
#pragma mark - public methods
-(void)setViewController:(UIViewController *)newController {
if (activeViewController != newController) {
activeViewController = newController;
}
}
-(void)addPinpointWithObject:(id)object mapPosition:(JMMapPosition*)position pinpointType:(PINPOINT_TYPE)pinType
{
static UIImage *greenPin = nil;
static UIImage *redPin = nil;
static UIImage *directionPin = nil;
if (greenPin == nil) {
greenPin = [UIImage imageNamed:@"pin_green"];
redPin = [UIImage imageNamed:@"pin"];
//todo direction pin
directionPin = [UIImage imageNamed:@"pin_direction"];
}
UIImage *image = nil;
switch (pinType) {
case PINPOINT_TYPE_CHILD_OBJECT:
image = greenPin;
break;
case PINPOINT_TYPE_OBJECT:
image = redPin;
break;
case PINPOINT_TYPE_DIRECTION:
image = directionPin;
default:
break;
}
CGFloat width = image.size.width;
CGFloat height = image.size.height;
UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, width, height)];
[self setButton:button positionToCoords:position];
[button setBackgroundImage:image forState:UIControlStateNormal];
[mapView addSubview:button];
if (pinType == PINPOINT_TYPE_CHILD_OBJECT) {
[button setTag:[pinpoints count]];
[button addTarget:self action:@selector(pinpointPressed:) forControlEvents:UIControlEventTouchUpInside];
} else if (pinType == PINPOINT_TYPE_DIRECTION) {
[button setTag:[directions count]];
[button addTarget:self action:@selector(directionPressed:) forControlEvents:UIControlEventTouchUpInside];
}
//add pinpoint to register
[self addPinpointToArray:button position:position pinpointType:pinType object:object];
}
-(void) destroyAllMapView {
//[self dismissPopover];
[self setViewController:nil];
for (NSDictionary *dict in pinpoints) {
@autoreleasepool {
UIButton *button = [dict objectForKey:KEY_BUTTON];
[button removeTarget:nil action:NULL forControlEvents:UIControlEventAllEvents];
//[button removeFromSuperview];
}
}
[self setNilToEveryGlobalObject];
}