得到UIColor的总结

一种就是根据RGB可以返回需要的UIColor。这种是IOS自带的，在类库UIKit.framework中存在。

    UIColor *color = [UIColor colorWithRed:25 green:25 blue:25 alpha:1];

另一种就是，根据颜色代码，通过转换成RGB，得到UIColor。这种在实际的开发中运用得比较多，非常实用。

+ (UIColor *) colorWithHexString: (NSString *) stringToConvert
{
	NSString *cString = [[stringToConvert stringByTrimmingCharactersInSet:
						  [NSCharacterSet whitespaceAndNewlineCharacterSet]]
						 uppercaseString];
	
	// String should be 6 or 8 characters
	if ([cString length] < 6) return DEFAULT_VOID_COLOR;
	
	// strip 0X if it appears
	if ([cString hasPrefix:@"0X"]) cString = [cString substringFromIndex:2];
	
    NSRange myrange = [cString rangeOfString:@"#"];
    if (myrange.location != NSNotFound)
    {
        cString = [cString substringFromIndex:1];
    }
	if ([cString length] != 6) return DEFAULT_VOID_COLOR;
	// Separate into r, g, b substrings
	NSRange range;
	range.location = 0;
	range.length = 2;
	NSString *rString = [cString substringWithRange:range];
	
	range.location = 2;
	NSString *gString = [cString substringWithRange:range];
	
	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:1.0f];
}