1 -(void)setValue:(CGFloat)value{
 2 
 3     _value = value;
 4 
 5     // 刷新界面， 向view发消息：setNeedDisplay， 系统会去调用drawRect方法进行界面的重新显示。
 6 
 7     [self setNeedsDisplay];
 8 
 9 }
10 
11 // M_PI    π
12 
13 // M_PI_2  π/2
14 
15 // M_PI_4  π/4
16 
17 // M_2_PI  π/5
18 
19 // M_1_PI  π/10
20 
21 // Only override drawRect: if you perform custom drawing.
22 
23 // An empty implementation adversely affects performance during animation.
24 
25 - (void)drawRect:(CGRect)rect
26 
27 {
28 
29     // Drawing code
30 
31     [super drawRect:rect];
32 
33     CGContextRef context = UIGraphicsGetCurrentContext();
34 
35     CGContextSaveGState(context);
36 
37    
38 
39     UIBezierPath *path = [UIBezierPath bezierPath];
40 
41     CGFloat width = self.bounds.size.width;
42 
43     CGFloat height = self.bounds.size.height;
44 
45     CGFloat minVal = width > height ? height : width;
46 
47     CGFloat radius = minVal / 2 - 10;
48 
49     [path addArcWithCenter:CGPointMake(width / 2, height / 2) radius:radius startAngle:M_PI_2 * 3 endAngle:M_PI_2 * 3 + M_PI * 2 * self.value clockwise:YES];
50 
51     [path moveToPoint:CGPointMake(width / 2, 0)];
52 
53     [path addLineToPoint:CGPointMake(width / 2, height)];
54 
55     [path moveToPoint:CGPointMake(0, height / 2)];
56 
57     [path addLineToPoint:CGPointMake(width, height / 2)];
58 
59     path.lineWidth = 1;
60 
61     path.lineCapStyle = kCGLineJoinRound;
62 
63     [[UIColor blackColor] setStroke];
64 
65     [path stroke];
66 
67    
68 
69     CGContextRestoreGState(context);
70 
71 }

 1 - (void)drawRect:(CGRect)rect
 2 
 3 {
 4 
 5     // Drawing code
 6 
 7     [super drawRect:rect];
 8 
 9     CGContextRef context = UIGraphicsGetCurrentContext();
10 
11     CGContextSaveGState(context);
12 
13    
14 
15     UIBezierPath *path = [UIBezierPath bezierPath];
16 
17     // 起点
18 
19     [path moveToPoint:CGPointMake(60, 20)];
20 
21     // addCurveToPoint终点 controlPoint1控制点1  controlPoint2控制点2
22 
23     [path addCurveToPoint:CGPointMake(20, 120) controlPoint1:CGPointMake(20, 20) controlPoint2:CGPointMake(60, 120)];
24 
25     // 起点是20, 120 终点60, 220 控制点1:60, 120 控制点2：20, 220
26 
27     [path addCurveToPoint:CGPointMake(60, 220) controlPoint1:CGPointMake(60, 120) controlPoint2:CGPointMake(20, 220)];
28 
29     [[UIColor redColor] setStroke];
30 
31     path.lineWidth = 3;
32 
33     [path stroke];
34 
35 
36     CGContextRestoreGState(context);
37 
38 }

 1 - (void)drawRect:(CGRect)rect
 2 
 3 {
 4 
 5     // Drawing code
 6 
 7     [super drawRect:rect];
 8 
 9     CGContextRef context = UIGraphicsGetCurrentContext();
10 
11     CGContextSaveGState(context);
12 
13     NSString *str1 = @"hello world...";
14 
15     NSDictionary *attributes = @{NSFontAttributeName: [UIFont systemFontOfSize:30],NSForegroundColorAttributeName:[UIColor redColor]};
16 
17     // 使用坐标绘制字符串，不好的地方是如果字符串超过屏幕宽度就看不到了
18 
19     [str1 drawAtPoint:CGPointMake(10, 20) withAttributes:attributes];
20 
21     NSString *str2 = @"hello world...hello world...hello world...hello world...";
22 
23     // 使用rect绘制字符串，可以解决上面的问题，不过宽度和高度是写死的，如果高度写死那么如果字符串超出这个高度就也看不见了
24 
25     [str2 drawInRect:CGRectMake(10, 50, 300, 100) withAttributes:attributes];
26 
27     NSString *str3 = @"内容未知。。。内容未知。。。内容未知。。。内容未知。。。内容未知。。。";
28 
29     // 使用有弹性的rect绘制字符串，解决以上问题，高度是系统根据字符串计算的，options要使用LineFragmentOrigin
30 
31     CGRect size = [str3 boundingRectWithSize:CGSizeMake(200, 600) options:NSStringDrawingUsesLineFragmentOrigin attributes:attributes context:nil];
32 
33     size.origin.x = 10;
34 
35     size.origin.y = 200;
36 
37     // NSLog(@"%lf,%lf",size.size.width,size.size.height);
38 
39     [str3 drawInRect:size withAttributes:attributes];
40 
41     CGContextRestoreGState(context);
42 
43 }

 1 - (void)viewDidLoad
 2 
 3 {
 4 
 5     [super viewDidLoad];
 6 
 7     UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
 8 
 9     UIImage *image = [UIImage imageNamed:@"ToolViewEmotion"];
10 
11     UIImage *imageHL = [UIImage imageNamed:@"ToolViewEmotionHL"];
12 
13     [button setImage:image forState:UIControlStateNormal];
14 
15     [button setImage:imageHL forState:UIControlStateHighlighted];
16 
17     button.frame = CGRectMake(30, 100, 35, 35);
18 
19     [self.view addSubview:button];
20 
21 }

 1 - (void)viewDidLoad
 2 
 3 {
 4 
 5     [super viewDidLoad];
 6 
 7     UIImage *image = [UIImage imageNamed:@"navigation_bar.png"];
 8 
 9     // 通过9切片技术切image
10 
11     UIImage *resizableImage = [image resizableImageWithCapInsets:UIEdgeInsetsMake(10, 10, 10, 10) resizingMode:UIImageResizingModeStretch];
12 
13     // 给navigationBar贴图
14 
15     [self.navigationController.navigationBar setBackgroundImage:resizableImage forBarMetrics:UIBarMetricsDefault];
16 
17 }

 1 - (void)viewDidLoad
 2 
 3 {
 4 
 5     [super viewDidLoad];
 6 
 7     UIImage *image = [UIImage imageNamed:@"delete_btn.png"];
 8 
 9     // 9切片技术
10 
11     UIImage *resizingImage =  [image resizableImageWithCapInsets:UIEdgeInsetsMake(11, 11, 11, 11) resizingMode:UIImageResizingModeStretch];// 拉伸
12 
13     [self.button setBackgroundImage:resizingImage forState:UIControlStateNormal];
14 
15 }