1橘沥、方案1
1.1魁袜、架構(gòu)
方案1.png
1.2养渴、實(shí)現(xiàn)
（1）設(shè)計(jì)一套皮膚文件配置協(xié)議
| ID | Value |
|---|---|
| com.xyz.color.title | 0x f f9b6a |
| com.xyz.color.background | 0xf1f2f3 |
| com.xyz.image.button.normal | back_n.png |
| com.xyz.image.button.selected | back_s.png |
| …… | …… |
（2）擴(kuò)展基類（NSObject + Theme），緩存對(duì)象和方法
// NSObject + Theme
- (NSMutableArray<ActionBloc> *)action {
NSMutableArray<ActionBloc> *action = objc_getAssociatedObject(self, @selector(action));
if (!action) {
// 不存在难咕，則創(chuàng)建關(guān)聯(lián)
action = [[NSMutableArray alloc] init];
objc_setAssociatedObject(self, @selector(action), action, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
return action;
}
// UIButton + Theme
- (void)them_setImageName:(NSString *)name forState:(UIControlState)state {
SetImage tmpBlock = ^(){
UIImage *image = [[ThemEngine sharedInstance] imageForThemeId:name];
[self setImage:image forState:state];
};
// 執(zhí)行
tmpBlock();
// 緩存方法
[self.action addObject:[tmpBlock copy]];
}
（3）應(yīng)用層初始化UI組件传蹈，例如UIButton
UIButton *firstBtn = [[UIButton alloc]initWithFrame:CGRectMake(100, 100, 120, 75)];
[firstBtn them_setImageName:@"normalImage" forState:UIControlStateNormal];
[[ThemEngine sharedInstance].themUI addObject:firstBtn]; // 緩存對(duì)象
[self.view addSubview:firstBtn];
（4）遍歷緩存對(duì)象和方法，實(shí)現(xiàn)換膚
- (void)changeThem {
for (int i = 0; i< self.themUI.count; i++) {
NSObject *obj = (NSObject *)[self.themUI objectAtIndex:i];
[obj.action enumerateObjectsUsingBlock:^(ActionBloc block, NSUInteger idx, BOOL *stop) {
block();
}];
}
}
2步藕、方案2
2.1、架構(gòu)
方案2.png
2.2挑格、實(shí)現(xiàn)
（1）設(shè)計(jì)一套皮膚文件配置協(xié)議
| ID | Value |
|---|---|
| com.xyz.color.title | 0x f f9b6a |
| com.xyz.color.background | 0xf1f2f3 |
| com.xyz.image.button.normal | back_n.png |
| com.xyz.image.button.selected | back_s.png |
| …… | …… |
（2）擴(kuò)展基類（NSObject+Theme）咙冗，緩存方法名和參數(shù)
- (void)cacheParams:(NSArray *)params forSelector:(SEL)sel
{
NSMutableDictionary *cachedParams = [self.cachedMethods objectForKey:NSStringFromSelector(sel)];
if (!cachedParams)
{
cachedParams = [[NSMutableDictionary alloc] init];
[self.cachedMethods setObject:cachedParams forKey:NSStringFromSelector(sel)];
}
/*
cachedMethods，當(dāng)前類緩存的方法和參數(shù)列表
{
selname : // 其中某個(gè)方法的參數(shù)列表
{
hash : <<[p1, p2, p3]>>,
hash : <<[p1, p2]>>
}
}
*/
NSString *hashKey = [self hashKeyForParams:params];
[cachedParams setObject:params forKey:hashKey];
}
（3）擴(kuò)展UIKit（UIButton+Theme等）漂彤，新增換膚方法
- (void)setImageWithIdentifier:(NSString *)identifier forState:(UIControlState)state
{
// 1雾消、注冊(cè)通知
[self registerThemeChangeNotification];
// 2、執(zhí)行原始方法
UIImage *image = [ThemeManager sharedManager].themeInfos[identifier];
[self setImage:image forState:state];
// 3挫望、緩存方法及參數(shù)
[self cacheParams:@[identifier.imageType, @(state)] forSelector:@selector(setImage:forState:)];
}
（4）ThemeManager發(fā)送換膚通知立润，遍歷執(zhí)行緩存的換膚方法
- (void)performAllCachedSelector
{
for (NSString *selName in [self.cachedMethods allKeys])
{
for (NSArray *params in [self.cachedMethods[selName] allValues])
{
[self performSelector:NSSelectorFromString(selName) params:params];
}
}
}
3、方案3
3.1媳板、架構(gòu)
方案3.png
3.2桑腮、實(shí)現(xiàn)
（1）設(shè)計(jì)一套皮膚文件配置協(xié)議
| ID | Value |
|---|---|
| com.xyz.color.title | 0x f f9b6a |
| com.xyz.color.background | 0xf1f2f3 |
| com.xyz.image.button.normal | back_n.png |
| com.xyz.image.button.selected | back_s.png |
| …… | …… |
（2）設(shè)計(jì)一套方法映射管理協(xié)議
| Class | Selector | MapID |
|---|---|---|
| UIButton | setImage:forState:（normal） | kThemeButtonNormalImage |
| UIButton | setImage:forState:（highlighted） | kThemeButtonHighlightedImage |
| UIButton | setImage:forState:（selected） | kThemeButtonSelectedImage |
| …… | …… | …… |
（3）擴(kuò)展UIView（UIView+Theme），添加換膚方法蛉幸，保存對(duì)應(yīng)關(guān)系《MapID — SkinID》
- (void)setThemeMap:(NSDictionary *)themeMap
{
// 1破讨、保存對(duì)應(yīng)關(guān)系
objc_setAssociatedObject(self, &kUIView_ThemeMap, themeMap, OBJC_ASSOCIATION_COPY_NONATOMIC);
if (themeMap) {
// 2丛晦、注冊(cè)通知
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(themeChanged) name:kThemeDidChangeNotification object:nil];
// 3、執(zhí)行換膚方法
[self themeChanged];
}
else {
[[NSNotificationCenter defaultCenter] removeObserver:self name:kThemeDidChangeNotification object:nil];
}
}
（4）應(yīng)用層初始化UI組件提陶，例如UIButton
- (void)viewDidLoad {
[super viewDidLoad];
UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.themeMap =
@{kThemeButtonNormalImage : @"com.ac.image.button.normal",
kThemeButtonSelectedImage : @“com.ac.image.button.selected"};
[self.view addSubview:btn];
}
（5）ThemeManager發(fā)送換膚通知烫沙，執(zhí)行換膚方法
- (void)themeChanged
{
NSDictionary *map = self.themeMap;
if ([self isKindOfClass:[UIButton class]]) {
UIButton *obj = (UIButton *)self;
if (map[kThemeButtonNormalImage]) {
NSString *skinId = map[kThemeButtonNormalImage];
UIImage *image = [ThemeManager sharedInstance].themeConfig[skinId];
[obj setImage:image forState:UIControlStateNormal];
}
if (map[kThemeButtonSelectedImage]) {
NSString *skinId = map[kThemeButtonSelectedImage];
UIImage *image = [ThemeManager sharedInstance].themeConfig[skinId];
[obj setImage:image forState:UIControlStateSelected];
}
}
TODO: 遍歷執(zhí)行其他UIKit控件的方法，例如UILabel
}
4隙笆、方案對(duì)比
4.1锌蓄、分析
從架構(gòu)層面來看，這3種方案的實(shí)現(xiàn)思路基本一致撑柔，具備相同的優(yōu)點(diǎn)：
（1）利用通知或Block機(jī)制瘸爽，解耦模塊；
（2）皮膚文件利用ID特性乏冀，方便維護(hù)擴(kuò)展蝶糯；
（3）利用Category特性，對(duì)現(xiàn)有代碼改動(dòng)較辛韭佟昼捍；
唯一的區(qū)別在于方法緩存器的設(shè)計(jì)和實(shí)現(xiàn)，這直接影響到換膚框架對(duì)App內(nèi)存的消耗肢扯，可通過Demo分析這3種方案的內(nèi)存占用妒茬。
4.2、案例
// 方案1
UIButton *testBtn = [[UIButton alloc] initWithFrame:CGRectMake(100, 100, 120, 75)];
[testBtn them_setImageName:@"normalImage" forState:UIControlStateNormal];
[[ThemEngine sharedInstance].themUI addObject:testBtn]; // 緩存對(duì)象
[self.view addSubview:testBtn];
// 方案2
UIButton *testBtn = [[UIButton alloc] initWithFrame:CGRectMake(100, 100, 120, 75)];
[testBtn setImageWithIdentifier:@"normalImage" forState:UIControlStateNormal];
[self.view addSubview:testBtn];
// 方案3
UIButton *testBtn = [[UIButton alloc] initWithFrame:CGRectMake(100, 100, 120, 75)];
testBtn.themeMap =
@{kThemeButtonNormalImage : @"normalImage"};
[self.view addSubview:testBtn];
實(shí)驗(yàn)結(jié)果：
|方案1 |方案2 |方案3
---------|------|--------|------
內(nèi)存消耗 |752 bytes |472 bytes |372 bytes
4.3蔚晨、對(duì)方案3的改進(jìn)：提高API的易用性
// 方案3
testBtn.themeMap =
@{kThemeButtonNormalImage : @"normalImage"};
// 方案3改進(jìn)
[testBtn setImageWithThemeId:@"normalImage" forState:UIControlStateNormal];
5乍钻、參考資料
（1）https://github.com/JyHu/EasyTheme
（2）https://github.com/jiecao-fm/SwiftTheme
（3）https://github.com/yanjunz/ThemeManager
如果讀者有更好的方案，歡迎留言铭腕，一起討論银择。
