iphone - CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext)

Question

到目前为止我已经有一幅画了。我有不同颜色的按钮，但我不知道如何更改它们的颜色。我有所有的 RGB 颜色代码，但是如何使用 IBAction 实现它，它会更改 CGContextSetRGBStrokeColor UIGraphicsGetCurrentContext()

.h:

@interface GameScreen : UIViewController {

    BOOL mouseSwiped;
    float lineWidth;
    CGPoint lastPoint;
    IBOutlet UIImageView *drawImage;
}
@end

.m:

#import "GameScreen.h"
#import "DoodlePicViewController.h"
#import "Settings.h"

@implementation GameScreen

@synthesize theimageView,choosePhoto, takePhoto;

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    mouseSwiped = NO;
    UITouch *touch = [touches anyObject];
    lineWidth = thickness.value;

    lastPoint = [touch locationInView:self.view];
    lastPoint.y -= 20;

}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    mouseSwiped = YES;

    UITouch *touch = [touches anyObject];   
    CGPoint currentPoint = [touch locationInView:self.view];
    currentPoint.y -= 20;


    UIGraphicsBeginImageContext(self.view.frame.size);
    [drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
    CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
    CGContextSetLineWidth(UIGraphicsGetCurrentContext(), lineWidth);
    CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(),1.0, 1.0, 1.0, 1.0);
    CGContextBeginPath(UIGraphicsGetCurrentContext());
    CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
    CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y);
    CGContextStrokePath(UIGraphicsGetCurrentContext());
    drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    lastPoint = currentPoint;



}



- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {

    UITouch *touch = [touches anyObject];


    if(!mouseSwiped) {
        UIGraphicsBeginImageContext(self.view.frame.size);
        [drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
        CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
        CGContextSetLineWidth(UIGraphicsGetCurrentContext(), lineWidth);
        CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 1.0, 0.0, 0.0, 1.0);
        CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
        CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
        CGContextStrokePath(UIGraphicsGetCurrentContext());
        CGContextFlush(UIGraphicsGetCurrentContext());
        drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
    }
}


@end

我真的很想弄清楚，但我被困住了☹

Answer 1

我认为你可以使用 slider ，因为它的值是从0到1。你可以获取3个 slider 的值，然后将它们传递给CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(),1.0, 1.0, 1.0, 1.0) ，没有IB你也可以做到。我不认为IB是一件好事。