ios绘制方法

- (void)drawRect:(CGRect)rect
{
//画矩形
CGContextRef context = UIGraphicsGetCurrentContext();

CGContextSetLineWidth(context, 5.0);

CGContextSetStrokeColorWithColor(context, [[UIColor blueColor] CGColor]);
//以此为起点
CGContextMoveToPoint(context, rect.origin.x, rect.origin.y);
//画四条线，以上一个点为起点，设置线终点
CGContextAddLineToPoint(context, rect.size.width, rect.origin.y);
CGContextAddLineToPoint(context, rect.size.width, rect.size.height);
CGContextAddLineToPoint(context, rect.origin.x, rect.size.height);
CGContextAddLineToPoint(context, rect.origin.x, rect.origin.y);

CGContextStrokePath(context);

}

- (void)drawRect:(CGRect)rect
{
//画文字
UIFont *font = [UIFont systemFontOfSize:8];
//在指定x，y点位置画文字，宽度为18
NSString* str = @"在指定x，y点位置画文字，宽度为18";
[str drawAtPoint:CGPointMake(20, 20) withAttributes:@{NSFontAttributeName: font,NSForegroundColorAttributeName:[UIColor redColor]}];

}

-(void)animationImageView
{
UIImageView* animationImageView = [[UIImageView alloc] initWithFrame:self.view.frame];
animationImageView.animationImages = @[[UIImage imageNamed:@"loading-1.png"],[UIImage imageNamed:@"loading-2.png"],[UIImage imageNamed:@"loading-3.png"],[UIImage imageNamed:@"loading-4.png"]];

// imageFrames 是一个图片数组   animationImageView是一个imageview
//    [UIView setAnimationDelegate:self];
animationImageView.animationDuration = 0.75f;
animationImageView.animationRepeatCount = 0;
[animationImageView startAnimating];
[self.view addSubview:animationImageView];
}