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当我启动我的应用程序,我不断收到这个CGContextFillEllipseInRect:无效的上下文错误。我的应用程序只是为了让这个圈子变得“可捏造”。CGContextFillEllipseInRect:无效的上下文
调试器显示我:
[Session started at 2010-05-23 18:21:25 +0800.]
2010-05-23 18:21:27.140 Erase[8045:207] I'm being redrawn.
Sun May 23 18:21:27 Sidwyn-Kohs-MacBook-Pro.local Erase[8045] <Error>: CGContextFillEllipseInRect: invalid context
2010-05-23 18:21:27.144 Erase[8045:207] New value of counter is 1
2010-05-23 18:21:27.144 Erase[8045:207] I'm being redrawn.
Sun May 23 18:21:27 Sidwyn-Kohs-MacBook-Pro.local Erase[8045] <Error>: CGContextFillEllipseInRect: invalid context
2010-05-23 18:21:27.144 Erase[8045:207] New value of counter is 2
2010-05-23 18:21:27.144 Erase[8045:207] I'm being redrawn.
Sun May 23 18:21:27 Sidwyn-Kohs-MacBook-Pro.local Erase[8045] <Error>: CGContextFillEllipseInRect: invalid context
2010-05-23 18:21:27.144 Erase[8045:207] New value of counter is 3
2010-05-23 18:21:27.145 Erase[8045:207] I'm being redrawn.
Sun May 23 18:21:27 Sidwyn-Kohs-MacBook-Pro.local Erase[8045] <Error>: CGContextFillEllipseInRect: invalid context
2010-05-23 18:21:27.145 Erase[8045:207] New value of counter is 4
2010-05-23 18:21:27.148 Erase[8045:207] I'm being redrawn.
Sun May 23 18:21:27 Sidwyn-Kohs-MacBook-Pro.local Erase[8045] <Error>: CGContextFillEllipseInRect: invalid context
2010-05-23 18:21:27.149 Erase[8045:207] New value of counter is 5
2010-05-23 18:21:27.150 Erase[8045:207] I'm being redrawn.
Sun May 23 18:21:27 Sidwyn-Kohs-MacBook-Pro.local Erase[8045] <Error>: CGContextFillEllipseInRect: invalid context
2010-05-23 18:21:27.150 Erase[8045:207] New value of counter is 6
我的执行文件是:
//
// ImageView.m
// Erase
//
#import "ImageView.h"
#import "EraseViewController.h"
@implementation ImageView
-(void)setNewRect:(CGRect)anotherRect{
newRect = anotherRect;
}
- (id)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
newRect = CGRectMake(0,0,0,0);
ref = UIGraphicsGetCurrentContext();
}
return self;
}
- (void)drawRect:(CGRect)rect {
static int counter = 0;
CGRect veryNewRect = CGRectMake(30.0, 210.0, 60.0, 60.0);
NSLog(@"I'm being redrawn.");
if (counter == 0){
CGContextFillEllipseInRect(ref, veryNewRect);
}
else{
CGContextFillEllipseInRect(ref, rect);
}
counter++;
NSLog(@"New value of counter is %d", counter);
}
- (void)setNeedsDisplay{
[super setNeedsDisplay];
[self drawRect:newRect];
}
- (void)dealloc {
[super dealloc];
}
@end
我有两个问题: 1)为什么更新计数器6倍?我删除了行[super setNeedsDisplay];
,但它变成了4次。 2)什么是无效的上下文错误?
谢谢你们。
嗨马塞洛,谢谢你的回复。 刚才你说的1)删除重写的setNeedsDisplay 2)把CGContextRef上下文放在drawRect:方法中。 但是,我仍然收到2个电话,当我启动应用程序时,会有一个适合屏幕宽度和高度的巨大椭圆形。 有什么想法? – 2010-05-23 10:33:14
巨大的椭圆是由于第二次调用('counter == 1'),然后调用第二个椭圆代码并使用框架传递的'rect'。基本上建议您绘制整个屏幕。你曾经调用过'setNeedsDisplay:'或'setNeedsDisplayInRect:'吗?这可能解释了这两个电话。 – 2010-05-23 10:58:19