在将UIColor
保存到NSUserDefaults
中并检索出来的过程中,最简单的方法是什么?
在将UIColor
保存到NSUserDefaults
中并检索出来的过程中,最简单的方法是什么?
可能有一种方法是将其归档(就像使用NSColor一样,尽管我还没有测试过):
NSData *colorData = [NSKeyedArchiver archivedDataWithRootObject:color];
[[NSUserDefaults standardUserDefaults] setObject:colorData forKey:@"myColor"];
并且要取回它:
NSData *colorData = [[NSUserDefaults standardUserDefaults] objectForKey:@"myColor"];
UIColor *color = [NSKeyedUnarchiver unarchiveObjectWithData:colorData];
NSData *colorData = [NSKeyedArchiver archivedDataWithRootObject:_mySprite.color]; [[NSUserDefaults standardUserDefaults] setObject:colorData forKey:@"spriteColor"];
- Jasonvar colorData:NSData = NSKeyedArchiver.archivedDataWithRootObject(color); defaults.setObject(colorData, forKey: "BackgroundColor");
- FredL使用被认可的答案,你的代码中将很快出现许多NSKeyed存档和解档。更清晰的解决方案是扩展UserDefaults。这正是扩展的用途; UserDefaults可能不知道UIColor,因为UIKit和Foundation是不同的框架。
extension UserDefaults {
func color(forKey key: String) -> UIColor? {
var color: UIColor?
if let colorData = data(forKey: key) {
color = NSKeyedUnarchiver.unarchiveObject(with: colorData) as? UIColor
}
return color
}
func set(_ value: UIColor?, forKey key: String) {
var colorData: Data?
if let color = value {
colorData = NSKeyedArchiver.archivedData(withRootObject: color)
}
set(colorData, forKey: key)
}
}
extension UserDefaults {
func color(forKey key: String) -> UIColor? {
guard let colorData = data(forKey: key) else { return nil }
do {
return try NSKeyedUnarchiver.unarchivedObject(ofClass: UIColor.self, from: colorData)
} catch let error {
print("color error \(error.localizedDescription)")
return nil
}
}
func set(_ value: UIColor?, forKey key: String) {
guard let color = value else { return }
do {
let data = try NSKeyedArchiver.archivedData(withRootObject: color, requiringSecureCoding: false)
set(data, forKey: key)
} catch let error {
print("error color key data not saved \(error.localizedDescription)")
}
}
}
UserDefaults.standard.set(UIColor.white, forKey: "white")
let whiteColor = UserDefaults.standard.color(forKey: "white")
使用 Objective-C 的类别也可以实现此操作。
我已将 Swift 文件添加到 此处 作为要点。
const CGFloat *components = CGColorGetComponents(pColor.CGColor);
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
[prefs setFloat:components[0] forKey:@"cr"];
[prefs setFloat:components[1] forKey:@"cg"];
[prefs setFloat:components[2] forKey:@"cb"];
[prefs setFloat:components[3] forKey:@"ca"];
加载
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
UIColor* tColor = [UIColor colorWithRed:[prefs floatForKey:@"cr"] green:[prefs floatForKey:@"cg"] blue:[prefs floatForKey:@"cb"] alpha:[prefs floatForKey:@"ca"]];
UIColor
类别,我可以将RGB颜色转换为/从可以保存在首选项中的NSString
。// Save a color
NSString *theColorStr = [self.artistColor stringFromColor];
[[NSUserDefaults standardUserDefaults] setObject:theColorStr forKey:@"myColor"];
// Read a color
NSString *theColorStr = [[NSUserDefaults standardUserDefaults] objectForKey:@"myColor"];
if ([theColorStr length] > 0) {
self.myColor = [UIColor colorWithString:theColorStr];
} else {
self.myColor = [UIColor colorWithRed:88.0/255.0 green:151.0/255.0 blue:237.0/255.0 alpha:1.0];
}
[NSUserDefaults registerDefaults:]
来设置默认值(这样在读取值时就可以避免 if/else)。 - benzadoUserDefaults
扩展extension UserDefaults {
internal func color(forKey key: String) -> UIColor? {
guard let colorData = data(forKey: key) else {
return nil
}
return NSKeyedUnarchiver.unarchiveObject(with: colorData) as? UIColor
}
internal func setColor(_ color: UIColor?, forKey key: String) {
let colorData: Data?
if let color = color {
colorData = NSKeyedArchiver.archivedData(withRootObject: color)
}
else {
colorData = nil
}
set(colorData, forKey: key)
}
}
let colorKey = "favoriteColor"
UserDefaults.standard.setColor(UIColor.red, forKey: colorKey)
let favoriteColor = UserDefaults.standard.color(forKey: colorKey)
print("favoriteColor is red: '\(favoriteColor == UIColor.red)'")
这个答案基于之前的回答,并针对Swift 3进行了更新。
我需要在用户默认设置中存储UIColor
对象的数组。正如其他答案所述,想法是将UIColor
转换为数据并保存该数据。我对UIColor
进行了扩展:
extension UIColor {
func data() -> Data {
return NSKeyedArchiver.archivedData(withRootObject: self)
}
class func color(withData data: Data) -> UIColor? {
return NSKeyedUnarchiver.unarchiveObject(with: data) as? UIColor
}
}
使用方法:
fileprivate var savedColors: [UIColor]? {
get {
if let colorDataArray = UserDefaults.standard.array(forKey: Constants.savedColorsKey) as? [Data] {
return colorDataArray.map { UIColor.color(withData: $0)! }
}
return nil
}
set {
if let colorDataArray = newValue?.map({ $0.data() }) {
UserDefaults.standard.set(colorDataArray, forKey: Constants.savedColorsKey)
}
}
}
private let colorPickerKey = "ColorPickerKey"
var selectedColor: UIColor? {
get {
guard let colorData = UserDefaults.standard.object(forKey: colorPickerKey) as? Data,
let color = NSKeyedUnarchiver.unarchiveObject(with: colorData) as? UIColor else { return nil }
return color
} set {
guard let newValue = newValue else {
UserDefaults.standard.removeObject(forKey: colorPickerKey)
return
}
let colorData = NSKeyedArchiver.archivedData(withRootObject: newValue)
UserDefaults.standard.set(colorData, forKey: colorPickerKey)
}
}
编辑2:我似乎已经找到了答案。请查看Erica Sadun关于扩展UIColor的文章。
编辑:这段代码似乎不能用于UIColor对象。不确定为什么...
以下是一些要查看的代码:
将对象保存到NSUserDefaults中:
NSUserDefaults *userDefaults =[NSUserDefaults standardUserDefaults];
[userDefaults setObject:someColorObject forKey:@"myColor"];
从NSUserDefaults读取对象:
NSUserDefaults *userDefaults =[NSUserDefaults standardUserDefaults];
UIColor *someColor = (UIColor *)[userDefaults objectForKey:@"myColor"];