iOS手寫簽名生成圖片
阿新 • • 發佈:2019-01-23
最近公司業務有一個需求,使用者認證時需要手動簽名,客戶端需要將使用者的簽名生成圖片上傳給伺服器。於是利用貝賽爾曲線研究了一下手動簽名,和大家分享一下。
Demo下載地址:https://github.com/TechAlleyBoy/SignDemo
效果圖
生成的圖片,這裡製作的是透明的簽名
一:繪製操作,主要利用的是貝賽爾曲線
注意:在呼叫setNeedsDisplay方法後,會在呼叫drawRect
#pragma mark - 初始化
- (instancetype)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
self.backgroundColor = [UIColor clearColor];
[self setMultipleTouchEnabled:NO];
self.beizerPath = [UIBezierPath bezierPath];
[self.beizerPath setLineWidth:2];
}
return self;
}
#pragma mark - 繪圖操作
- (void)drawRect:(CGRect)rect{
//設定簽名的顏色
UIColor *strokeColor = [UIColor redColor];
[strokeColor setStroke];
//簽名的路徑繪製
[self.beizerPath stroke];
}
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
self.control = 0;
UITouch *touch = [touches anyObject];
points[0] = [touch locationInView:self];
CGPoint startPoint = points[0];
CGPoint endPoint = CGPointMake(startPoint.x + 1.5, startPoint.y + 2);
[self.beizerPath moveToPoint:startPoint];
[self.beizerPath addLineToPoint:endPoint];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
CGPoint touchPoint = [touch locationInView:self];
_control++;
points[_control] = touchPoint;
if (_control == 4){
points[3] = CGPointMake((points[2].x + points[4].x)/2.0, (points[2].y + points[4].y)/2.0);
//設定畫筆起始點
[self.beizerPath moveToPoint:points[0]];
//endPoint終點 controlPoint1、controlPoint2控制點
[self.beizerPath addCurveToPoint:points[3] controlPoint1:points[1] controlPoint2:points[2]];
//setNeedsDisplay會自動呼叫drawRect方法,這樣可以拿到UIGraphicsGetCurrentContext,就可以畫畫了
[self setNeedsDisplay];
points[0] = points[3];
points[1] = points[4];
_control = 1;
}
}
二:清除簽名
注意:如何需要透明度的圖片時,首先view是透明的,然後一定生成png的圖片,否則不是黑色背景就是白色背景。
#pragma mark - 清除簽名
- (void)clearSignature{
[self.beizerPath removeAllPoints];
[self setNeedsDisplay];
}
三:獲取圖片
#pragma mark - 獲取圖片
- (UIImage *)getSignatureImage {
//設定為NO,UIView是透明這裡的圖片就是透明的
UIGraphicsBeginImageContextWithOptions(self.bounds.size, NO, [UIScreen mainScreen].scale);
[self.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *signatureImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSString* docDir = [NSString stringWithFormat:@"%@/Documents/Image", NSHomeDirectory()];
[[NSFileManager defaultManager] createDirectoryAtPath:docDir withIntermediateDirectories:YES attributes:nil error:nil];
NSString *path = [NSString stringWithFormat:@"%@/Documents/Image/IMAGE.PNG", NSHomeDirectory()];
//用png是透明的
[UIImagePNGRepresentation(signatureImage) writeToFile: path atomically:YES];
return signatureImage;
}