objective-c 将 UIColor 保存到 NSUserDefaults 并从 NSUserDefaults 加载
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原文地址: http://stackoverflow.com/questions/1275662/
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Saving UIColor to and loading from NSUserDefaults
提问by Unreality
What's the easiest way to save a UIColorinto NSUserDefaultsand then get it back out?
将 aUIColor存入NSUserDefaults然后将其取出的最简单方法是什么？
回答by Wevah
One way of doing it might be to archive it (like with NSColor, though I haven't tested this):
一种方法可能是将其存档（例如使用 NSColor，但我尚未对此进行测试）：
NSData *colorData = [NSKeyedArchiver archivedDataWithRootObject:color];
[[NSUserDefaults standardUserDefaults] setObject:colorData forKey:@"myColor"];
And to get it back:
并取回它：
NSData *colorData = [[NSUserDefaults standardUserDefaults] objectForKey:@"myColor"];
UIColor *color = [NSKeyedUnarchiver unarchiveObjectWithData:colorData];
回答by Andrew
With the accepted answer, you'll quickly end up with a lot of NSKeyed archives & unarchives all over your code. A cleaner solution is to extend UserDefaults. This is exactly what extensions are for; UserDefaults probably doesn't know about UIColor as it is because UIKit and Foundation are different frameworks.
有了接受的答案，您很快就会在代码中得到大量 NSKeyed 存档和取消存档。一个更简洁的解决方案是扩展 UserDefaults。这正是扩展的用途；UserDefaults 可能不了解 UIColor，因为 UIKit 和 Foundation 是不同的框架。
Swift
迅速
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)
}
}
Swift 4.2
斯威夫特 4.2
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)")
}
}
}
Usage
用法
UserDefaults.standard.set(UIColor.white, forKey: "white")
let whiteColor = UserDefaults.standard.color(forKey: "white")
This can also be done in Objective-C with a category.
这也可以在带有类别的 Objective-C 中完成。
I've added the Swift file as a gist here.
我已经添加了斯威夫特文件作为依据这里。
回答by Unreality
I've got the answer by myself
我自己有答案
Save
节省
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"];
Load
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"]];
回答by lifjoy
Thanks for Erica's UIColor category. I did not really like saving 4 floats in the preferences, and just wanted a single entry.
感谢Erica 的 UIColor 类别。我真的不喜欢在首选项中保存 4 个浮点数，只想要一个条目。
So using Erica's UIColorcategory, I was able to convert the RGBcolor to/from an NSStringwhich can be saved in the preferences.
因此，使用 Erica 的UIColor类别，我能够将RGB颜色转换为NSString可以保存在首选项中的RGB颜色。
// 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];
}
回答by Jovan Stankovic
I needed to store array of UIColorobjects in User Defaults. Idea, as stated in other answers, is to convert UIColorto Data and save that data. I've made extension on UIColor:
我需要UIColor在用户默认值中存储对象数组。正如其他答案中所述，想法是转换UIColor为数据并保存该数据。我已经扩展了UIColor：
extension UIColor {
func data() -> Data {
return NSKeyedArchiver.archivedData(withRootObject: self)
}
class func color(withData data: Data) -> UIColor? {
return NSKeyedUnarchiver.unarchiveObject(with: data) as? UIColor
}
}
Usage:
用法：
fileprivate var savedColors: [UIColor]? {
get {
if let colorDataArray = UserDefaults.standard.array(forKey: Constants.savedColorsKey) as? [Data] {
return colorDataArray.map { UIColor.color(withData: 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)
}
}
)! }
}
return nil
}
set {
if let colorDataArray = newValue?.map({ let colorKey = "favoriteColor"
UserDefaults.standard.setColor(UIColor.red, forKey: colorKey)
let favoriteColor = UserDefaults.standard.color(forKey: colorKey)
print("favoriteColor is red: '\(favoriteColor == UIColor.red)'")
.data() }) {
UserDefaults.standard.set(colorDataArray, forKey: Constants.savedColorsKey)
}
}
}
回答by Mobile Dan
Swift 3, UserDefaultsExtension
Swift 3，UserDefaults扩展
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)
}
}
Example Use
示例使用
NSUserDefaults *userDefaults =[NSUserDefaults standardUserDefaults];
[userDefaults setObject:someColorObject forKey:@"myColor"];
This answer is based on a previous answer. It is updated for Swift 3.
此答案基于先前的答案。它已针对 Swift 3 进行了更新。
回答by Warif Akhand Rishi
Swift
迅速
NSUserDefaults *userDefaults =[NSUserDefaults standardUserDefaults];
UIColor *someColor = (UIColor *)[userDefaults objectForKey:@"myColor"];
回答by zpesk
Edit 2:I seem to have found the answer. Check out the article by Erica Sadun on extending UIColor.
编辑 2：我似乎找到了答案。查看 Erica Sadun 关于扩展 UIColor 的文章。
Edit:This code does not seem to work for a UIColor Object. Not sure why...
编辑：此代码似乎不适用于 UIColor 对象。不知道为什么...
Here is some code to take a look at:
下面是一些代码来看看：
Saving an object into NSUserDefaults:
将对象保存到 NSUserDefaults 中：
##代码##Reading an object from NSUserDefaults:
从 NSUserDefaults 读取对象：
##代码##