前段时间有个朋友让帮忙写一个手写签名的功能，自己利用业余时间做了一下也算复习了下基础知识，现在整理出来写到简书上；
关于手写签名，我先是找了下别人的博客，有一个写的就很好，我把地址贴出来，大家可以参考一下
IOS：手写签名的实现实现了手势绘制字体，添加文字水印，图片剪切、图片压缩
主要是我的需求比较简单，看着人家写的这么详细 不忍心抄写，所以决定自己写，先上效果图：
我的思路是，在控制器中添加一个自定义的签名的View：signatureView，再设置一个重签的按钮用来清除重写，一个确认的按钮，将签名保存下来；
页面比较简单，为了少写一些成员变量，我把布局也写在了ViewDidLoad中
1、页面布局的代码如下：
1.1 页面布局
self.view.backgroundColor = [UIColor grayColor];
self.signatureView = [[signatureView alloc]initWithFrame:CGRectMake(10, 70, self.view.width - 20, (self.view.width - 20)*0.4)];
self.signatureView.backgroundColor = [UIColor whiteColor];
self.signatureView.color = [UIColor blackColor];
self.signatureView.lineWidth = 2;
[self.view addSubview:self.signatureView];
UIButton *reSignBtn = [UIButton buttonWithType:UIButtonTypeCustom];
[reSignBtn setTitle:@"重签" forState:UIControlStateNormal];
[reSignBtn setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
[reSignBtn setFrame:CGRectMake(20, CGRectGetMaxY(self.signatureView.frame)+10, (self.view.width - 20*3)*0.5, 40)];
reSignBtn.layer.cornerRadius = 5.0;
reSignBtn.clipsToBounds = YES;
reSignBtn.layer.borderWidth = 1.0;
reSignBtn.titleLabel.font = [UIFont systemFontOfSize:17];
[reSignBtn addTarget:self action:@selector(clear:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:reSignBtn];
UIButton *confirmBtn = [UIButton buttonWithType:UIButtonTypeCustom];
[confirmBtn setTitle:@"确认" forState:UIControlStateNormal];
[confirmBtn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
confirmBtn.titleLabel.font = [UIFont systemFontOfSize:17.0];
confirmBtn.backgroundColor = [UIColor greenColor];
confirmBtn.frame = CGRectMake(CGRectGetMaxX(reSignBtn.frame)+20, reSignBtn.y, reSignBtn.width, reSignBtn.height);
confirmBtn.layer.cornerRadius = 5.0;
confirmBtn.clipsToBounds = YES;
[confirmBtn addTarget:self action:@selector(confirmBtnClick:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:confirmBtn];
1.2 两个按钮的方法：
// 清除按钮方法
-(void)clear:(UIButton *)btn{
[self.signatureView clearScreen];
}
// 确定按钮方法
-(void)confirmBtnClick:(UIButton *)btn {
NSLog(@"确定保存");
// 开启位图上下文
UIGraphicsBeginImageContextWithOptions(_signatureView.bounds.size, NO, 0);
// 获取当前位图上下文
CGContextRef ctx = UIGraphicsGetCurrentContext();
// 截屏内容到上下文
[_signatureView.layer renderInContext:ctx];
// 获取图片
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
// 关闭上下文
UIGraphicsEndImageContext();
// 这里拿到签名后的图片，可以保存到相册
// 保存到手机相册
UIImageWriteToSavedPhotosAlbum(img, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
// 我这里是通过block传值给上一个页面
if (self.signBlock) {
self.signBlock(img);
}
[self.navigationController popViewControllerAnimated:YES];
}
如果保存到相册，回调方法：
// 保存相册成功之后的回调方法
- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
if (error) {
NSLog(@"保存成功");
// [MBProgressHUD showError:@"保存失败"];
}else{
// 保存成功
NSLog(@"保存失败");
//[MBProgressHUD showSuccess:@"保存成功"];
}
}```
###2. signatureView
首先重写initWithFrame: 设置默认的lineWidth 和color，我们把lineWidth和color设置成属性，暴露到.h头文件中，方便控制器中修改；
-(instancetype)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]){
_lineWidth = 1;
_color = [UIColor blackColor];
}
return self;
}
我们在touchesBegan: 和touchesMoved: 中创建和绘制UIBezierPath 路径
-
(CGPoint)pointWithTouches:(NSSet *)touches
{
// 获取touch对象
UITouch *touch = [touches anyObject];
// 获取当前触摸点
return [touch locationInView:self];
}
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{CGPoint curP = [self pointWithTouches:touches];
// 创建路径
DrawPath *path = [DrawPath pathWitchColor:_color lineWidth:_lineWidth];
[path moveToPoint:curP];
_path = path;[self.paths addObject:path];
}
-(void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
CGPoint curP = [self pointWithTouches:touches];
[_path addLineToPoint:curP];
[self setNeedsDisplay];
}
上面的DrawPath 是继承自UIBezierPath 的子类，为了给UIBezierPath拓展color属性
-
(instancetype)pathWitchColor:(UIColor *)color lineWidth:(CGFloat)lineWidth
{
DrawPath *path = [[self alloc] init];
path.color = color;
path.lineWidth = lineWidth;return path;
}
绘制完成后调用 [self setNeedsDisplay] 系统会调用 drawRect:方法完成绘制
-(void)drawRect:(CGRect)rect{
if (self.paths.count == 0) {
return;
}
for (DrawPath *path in self.paths) {
[path.color set];
[path stroke];
}
}
另外的清屏操作和懒加载代码如下：
// 清屏
-
(void)clearScreen
{
// 清空所有的路径
[self.paths removeAllObjects];[self setNeedsDisplay];
}
// 懒加载
-(NSMutableArray *)paths{
if (!_path) {
_paths = [NSMutableArray array];}
return _paths;
}
如此我们就用绘图的方法 简单实现了手写签名功能；