xcode - 按下按钮后为 DrawRect 设置NeedsDisplay

Question

我在 NSView 上的自定义类中有这个，当我使用 drawMyRec IBAction 按下按钮时，我想更改 NSRect 的颜色，但这不起作用，任何人都可以帮忙吗？

#import "myView.h"

@implementation myView

- (id)initWithFrame:(NSRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        RectColor = [[NSColor blackColor] init];
    }

    return self;
}


- (IBAction)drawMyRec:(id)sender;
{
    NSLog(@"pressed");
    RectColor = [[NSColor blueColor] init];
    [self setNeedsDisplay:YES];
}


- (void)drawRect:(NSRect)dirtyRect
{
    NSRectFill(dirtyRect);
    [RectColor set];

}

@end

Answer 1

您的drawRect函数不正确。更改为:

- (void)drawRect:(NSRect)dirtyRect
{
    [RectColor set];
    NSRectFill(dirtyRect);

}