创建一个分类Category： 支持十六进制Hex颜色设置。
新建 -> Objective-c File 选择 Category
只需输入为分类起的名字Hex，会自动生成分类名字的格式 UIColor+Hex
//.h文件
#define RGBA_COLOR(R, G, B, A) [UIColor colorWithRed:((R) / 255.0f) green:((G) / 255.0f) blue:((B) / 255.0f) alpha:A]
#define RGB_COLOR(R, G, B) [UIColor colorWithRed:((R) / 255.0f) green:((G) / 255.0f) blue:((B) / 255.0f) alpha:1.0f]
+ (UIColor *)colorWithHexString:(NSString *)color;
//从十六进制字符串获取颜色，
//color:支持@“#123456”、 @“0X123456”、 @“123456”三种格式
+ (UIColor *)colorWithHexString:(NSString *)color alpha:(CGFloat)alpha;
+ (UIColor *)colorFromHexRGB:(NSString *)inColorString;
+ (UIImage *)imageWithColor:(UIColor *)color ;
//.m 文件
+ (UIColor *)colorWithHexString:(NSString *)color alpha:(CGFloat)alpha
{
//删除字符串中的空格
NSString *cString = [[color stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
// String should be 6 or 8 characters
if ([cString length] < 6){
return [UIColor clearColor];
}
// strip 0X if it appears
//如果是0x开头的，那么截取字符串，字符串从索引为2的位置开始，一直到末尾
if ([cString hasPrefix:@"0X"]){
cString = [cString substringFromIndex:2];
}
//如果是#开头的，那么截取字符串，字符串从索引为1的位置开始，一直到末尾
if ([cString hasPrefix:@"#"]){
cString = [cString substringFromIndex:1];
}
if ([cString length] != 6){
return [UIColor clearColor];
}
// Separate into r, g, b substrings
NSRange range;
range.location = 0;
range.length = 2;
//r
NSString *rString = [cString substringWithRange:range];
//g
range.location = 2;
NSString *gString = [cString substringWithRange:range];
//b
range.location = 4;
NSString *bString = [cString substringWithRange:range];
// Scan values
unsigned int r, g, b;
[[NSScanner scannerWithString:rString] scanHexInt:&r];
[[NSScanner scannerWithString:gString] scanHexInt:&g];
[[NSScanner scannerWithString:bString] scanHexInt:&b];
return [UIColor colorWithRed:((float)r / 255.0f) green:((float)g / 255.0f) blue:((float)b / 255.0f) alpha:alpha];
}
//默认alpha值为1
+ (UIColor *)colorWithHexString:(NSString *)color
{
return [self colorWithHexString:color alpha:1.0f];
}
/*!
* method 通过16进制计算颜色
* abstract
* discussion
* param 16机制
* result 颜色对象
*/
+ (UIColor *)colorFromHexRGB:(NSString *)inColorString
{
UIColor *result = nil;
unsigned int colorCode = 0;
unsigned char redByte, greenByte, blueByte;
if (nil != inColorString)
{
NSScanner *scanner = [NSScanner scannerWithString:inColorString];
(void) [scanner scanHexInt:&colorCode]; // ignore error
}
redByte = (unsigned char) (colorCode >> 16);
greenByte = (unsigned char) (colorCode >> 8);
blueByte = (unsigned char) (colorCode); // masks off high bits
result = [UIColor
colorWithRed: (float)redByte / 0xff
green: (float)greenByte/ 0xff
blue: (float)blueByte / 0xff
alpha:1.0];
return result;
}
//UIColor转换成一张UIImage
+ (UIImage *)imageWithColor:(UIColor *)color {
CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f); //宽高 1.0只要有值就够了
UIGraphicsBeginImageContext(rect.size); //在这个范围内开启一段上下文
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [color CGColor]);//在这段上下文中获取到颜色UIColor
CGContextFillRect(context, rect);//用这个颜色填充这个上下文
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();//从这段上下文中获取Image属性,,,结束
UIGraphicsEndImageContext();
return image;
}
如何使用：
//直接在其他文件中：
UIColor *myColor = [UIColor 方法名];
