项目中经常会用到颜色转换，有的是通过十六进制转成数字转颜色，想简单的点直接通过字符串转一下，简单扩展了一下分类UIColor，代码如下:
+(UIColor *)colorWithHex:(NSString *)hexColor{
return [self colorWithHex:hexColor alpha:1.0f];
}
//Http://www.cnblogs.com/xiaofeixiang iOS技术交流:228407086
+(UIColor *)colorWithHex:(NSString *)hexColor alpha:(float)alpha{
//删除空格
NSString *colorStr = [[hexColor stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
// String should be 6 or 8 characters
if ([colorStr length] < 6||[colorStr length]>7)
{
return [UIColor clearColor];
}
//
if ([colorStr hasPrefix:@"#"])
{
colorStr = [colorStr substringFromIndex:1];
}
NSRange range;
range.location = 0;
range.length = 2;
//red
NSString *redString = [colorStr substringWithRange:range];
//green
range.location = 2;
NSString *greenString = [colorStr substringWithRange:range];
//blue
range.location = 4;
NSString *blueString= [colorStr substringWithRange:range];
// Scan values
unsigned int red, green, blue;
[[NSScanner scannerWithString:redString] scanHexInt:&red];
[[NSScanner scannerWithString:greenString] scanHexInt:&green];
[[NSScanner scannerWithString:blueString] scanHexInt:&blue];
return [UIColor colorWithRed:((float)red/ 255.0f) green:((float)green/ 255.0f) blue:((float)blue/ 255.0f) alpha:alpha];
}