开发日常

设置导航栏返回键

let navigationitom = UIBarButtonItem(image: UIImage(named: "main_navi_left"), style: .plain, target: self, action: #selector(didClickBackButton))
self.navigationItem.leftBarButtonItem = navigationitom

暗黑模式的判断

UIUserInterfaceStyle userInterfaceStyle = [UITraitCollection currentTraitCollection].userInterfaceStyle;
if(userInterfaceStyle == UIUserInterfaceStyleLight){

}else{

}

- (void) traitCollectionDidChange:(UITraitCollection *)previousTraitCollection
{
    [super traitCollectionDidChange:previousTraitCollection];
    UIUserInterfaceStyle userInterfaceStyle = previousTraitCollection.userInterfaceStyle;
    if(userInterfaceStyle == UIUserInterfaceStyleLight){

    }else{

    }
}

屏蔽暗黑模式
plist文件设置

<key>UIUserInterfaceStyle</key>
    <string>Light</string>

把字符串“#ff00ff00”转换为UIColor对象，前面两位代表透明度，后面分别代表RGB颜色

func colorFromHexString(_ hexString: String) -> UIColor? {
    // 去掉字符串中的空格和换行符
    let trimmedString = hexString.trimmingCharacters(in: .whitespacesAndNewlines)
    
    // 判断字符串是否以 # 符号开头
    guard trimmedString.hasPrefix("#") else {
        return nil
    }
    
    // 截取字符串中的透明度、红、绿、蓝四种颜色的数值
    let startIndex = trimmedString.index(trimmedString.startIndex, offsetBy: 1)
    let endIndex = trimmedString.index(startIndex, offsetBy: 2)
    let alphaIndex = trimmedString.index(startIndex, offsetBy: 2)
    let redIndex = trimmedString.index(alphaIndex, offsetBy: 2)
    let greenIndex = trimmedString.index(redIndex, offsetBy: 2)
    let blueIndex = trimmedString.index(greenIndex, offsetBy: 2)
    
    let alphaHex = String(trimmedString[startIndex..<endIndex])
    let redHex = String(trimmedString[alphaIndex..<redIndex])
    let greenHex = String(trimmedString[redIndex..<greenIndex])
    let blueHex = String(trimmedString[greenIndex..<blueIndex])
    
    // 将十六进制数值转换为 UIColor 对象
    if let alpha = UInt8(alphaHex, radix: 16),
       let red = UInt8(redHex, radix: 16),
       let green = UInt8(greenHex, radix: 16),
       let blue = UInt8(blueHex, radix: 16) {
        return UIColor(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: CGFloat(alpha) / 255.0)
    }
    
    return nil
}

oc代码

+ (UIColor *)colorFromHexString:(NSString *)hexString {
    // 去掉字符串中的空格和换行符
    NSString *trimmedString = [hexString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
    
    // 判断字符串是否以 # 符号开头
    if (![trimmedString hasPrefix:@"#"]) {
        return nil;
    }
    
    // 截取字符串中的透明度、红、绿、蓝四种颜色的数值
    NSRange alphaRange = NSMakeRange(1, 2);
    NSRange redRange = NSMakeRange(3, 2);
    NSRange greenRange = NSMakeRange(5, 2);
    NSRange blueRange = NSMakeRange(7, 2);
    
    NSString *alphaHex = [trimmedString substringWithRange:alphaRange];
    NSString *redHex = [trimmedString substringWithRange:redRange];
    NSString *greenHex = [trimmedString substringWithRange:greenRange];
    NSString *blueHex = [trimmedString substringWithRange:blueRange];
    
    // 将十六进制数值转换为 UIColor 对象
    unsigned int alpha, red, green, blue;
    NSScanner *scanner = [NSScanner scannerWithString:alphaHex];
    [scanner scanHexInt:&alpha];
    scanner = [NSScanner scannerWithString:redHex];
    [scanner scanHexInt:&red];
    scanner = [NSScanner scannerWithString:greenHex];
    [scanner scanHexInt:&green];
    scanner = [NSScanner scannerWithString:blueHex];
    [scanner scanHexInt:&blue];
    
    return [UIColor colorWithRed:(CGFloat)red / 255.0 green:(CGFloat)green / 255.0 blue:(CGFloat)blue / 255.0 alpha:(CGFloat)alpha / 255.0];
}