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）

最近要实现一个手写签名功能，要求是，在一定区域绘制文字签名，签名完成后，添加新的水印，并且将图片仅保留签字区域剪切，并且宽度不能大于128，经多方努力，终于完成了，现在上代码，总结一下：

首先，新建单视图项目，然后新建一个继承view的类signatureView，绘制功能和图片的处理就是在该类实现的，该类代码如下：

.h文件

#import <UIKit/UIKit.h>

@protocol GetSignatureImageDele <NSObject>

-(void)getSignatureImg:(UIImage*)image;

@end

@interface signatureView :
UIView

{

CGFloat min;

CGFloat max;

CGRect origRect;

CGFloat origionX;

CGFloat totalWidth;

BOOL isSure;

}

//签名完成后的水印文字

@property (strong,nonatomic)
NSString *showMessage;

@property(nonatomic,assign)id<GetSignatureImageDele> delegate;

- (void)clear;

- (void)sure;

@end

.m文件

#import "signatureView.h"

#import <QuartzCore/QuartzCore.h>

#define StrWidth 150

#define StrHeight 20

staticCGPoint midpoint(CGPoint p0,CGPoint
p1) {
return (CGPoint) {
(p0.x + p1.x) /2.0,
(p0.y + p1.y) /2.0
};
}

@interface
signatureView () {

UIBezierPath *path;
CGPoint previousPoint;
}

@end

@implementation signatureView
- (void)commonInit {

path = [UIBezierPathbezierPath];

[pathsetLineWidth:2];

max =
0;
min =
0;

// Capture touches

UIPanGestureRecognizer *pan = [[UIPanGestureRecognizeralloc]
initWithTarget:selfaction:@selector(pan:)];

pan.maximumNumberOfTouches = pan.minimumNumberOfTouches =1;

[selfaddGestureRecognizer:pan];

}

-(void)clearPan
{

path = [UIBezierPathbezierPath];

[pathsetLineWidth:3];

[selfsetNeedsDisplay];
}

- (id)initWithCoder:(NSCoder *)aDecoder
{
if (self = [superinitWithCoder:aDecoder])
[selfcommonInit];

return
self;
}
- (id)initWithFrame:(CGRect)frame
{
if (self = [superinitWithFrame:frame])
[selfcommonInit];

return
self;
}

void ProviderReleaseData (void *info,const
void *data,size_t size)
{
free((void*)data);
}

- (UIImage*) imageBlackToTransparent:(UIImage*) image
{

//
分配内存
const
int imageWidth = image.size.width;
const
int imageHeight = image.size.height;
size_t bytesPerRow = imageWidth *
4;
uint32_t* rgbImageBuf = (uint32_t*)malloc(bytesPerRow * imageHeight);

//
创建context

CGColorSpaceRef colorSpace =CGColorSpaceCreateDeviceRGB();
CGContextRef context =
CGBitmapContextCreate(rgbImageBuf, imageWidth, imageHeight,
8, bytesPerRow, colorSpace,
kCGBitmapByteOrder32Little |
kCGImageAlphaNoneSkipLast);

CGContextDrawImage(context,
CGRectMake(0,
0, imageWidth, imageHeight), image.CGImage);

//
遍历像素
int pixelNum = imageWidth * imageHeight;
uint32_t* pCurPtr = rgbImageBuf;
for (int i =0; i < pixelNum; i++, pCurPtr++)
{

// if ((*pCurPtr & 0xFFFFFF00) == 0) //将黑色变成透明
if (*pCurPtr ==
0xffffff)
{
uint8_t* ptr = (uint8_t*)pCurPtr;
ptr[0] =0;
}

//改成下面的代码，会将图片转成灰度

/*uint8_t* ptr = (uint8_t*)pCurPtr;

// gray = red * 0.11 + green * 0.59 + blue * 0.30

uint8_t gray = ptr[3] * 0.11 + ptr[2] * 0.59 + ptr[1] * 0.30;

ptr[3] = gray;

ptr[2] = gray;

ptr[1] = gray;*/
}

//
将内存转成image
CGDataProviderRef dataProvider =
CGDataProviderCreateWithData(NULL, rgbImageBuf, bytesPerRow * imageHeight,ProviderReleaseData);
CGImageRef imageRef =
CGImageCreate(imageWidth, imageHeight,
8,32, bytesPerRow, colorSpace,
kCGImageAlphaLast |
kCGBitmapByteOrder32Little, dataProvider,
NULL,
true,kCGRenderingIntentDefault);

CGDataProviderRelease(dataProvider);

UIImage* resultUIImage = [UIImageimageWithCGImage:imageRef];

//
释放
CGImageRelease(imageRef);

CGContextRelease(context);

CGColorSpaceRelease(colorSpace);

// free(rgbImageBuf)
创建dataProvider时已提供释放函数，这里不用free

return resultUIImage;
}

-(void)handelSingleTap:(UITapGestureRecognizer*)tap
{

return [selfimageRepresentation];
}
-(void) imageRepresentation {

if(UIGraphicsBeginImageContextWithOptions !=NULL)
{

UIGraphicsBeginImageContextWithOptions(self.bounds.size,NO,
[UIScreenmainScreen].scale);
}else {

UIGraphicsBeginImageContext(self.bounds.size);

}

[self.layerrenderInContext:UIGraphicsGetCurrentContext()];

UIImage *image =UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

image = [selfimageBlackToTransparent:image];

NSLog(@"width:%f,height:%f",image.size.width,image.size.height);

UIImage *img = [selfcutImage:image];

[self.delegategetSignatureImg:[selfscaleToSize:img]];
}

//压缩图片,最长边为128
- (UIImage *)scaleToSize:(UIImage *)img {
CGRect rect ;
CGFloat imageWidth = img.size.width;

//判断图片宽度
if(imageWidth >=
128)
{
rect =CGRectMake(0,0,
128, self.frame.size.height);
}
else
{
rect =CGRectMake(0,0, img.size.width,self.frame.size.height);

}
CGSize size = rect.size;

UIGraphicsBeginImageContext(size);
[imgdrawInRect:rect];

UIImage* scaledImage =UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

UIImageWriteToSavedPhotosAlbum(scaledImage,nil,
nil,
nil);

[selfsetNeedsDisplay];
return scaledImage;
}

//只截取签名部分图片
- (UIImage *)cutImage:(UIImage *)image
{
CGRect rect ;

//签名事件没有发生
if(min ==
0&&max ==
0)
{
rect =CGRectMake(0,0,
0, 0);
}

else//签名发生
{
rect =CGRectMake(min-3,0,
max-min+6,self.frame.size.height);
}

CGImageRef imageRef =CGImageCreateWithImageInRect([image
CGImage], rect);
UIImage * img = [UIImageimageWithCGImage:imageRef];

UIImage *lastImage = [selfaddText:img
text:self.showMessage];

[selfsetNeedsDisplay];
return lastImage;
}

//签名完成，给签名照添加新的水印
- (UIImage *) addText:(UIImage *)img text:(NSString *)mark {
int w = img.size.width;
int h = img.size.height;

//根据截取图片大小改变文字大小
CGFloat size =
20;
UIFont *textFont = [UIFontsystemFontOfSize:size];
CGSize sizeOfTxt = [mark
sizeWithFont:textFont
constrainedToSize:CGSizeMake(128,30)];

if(w<sizeOfTxt.width)
{

while (sizeOfTxt.width>w) {
size --;
textFont = [UIFontsystemFontOfSize:size];

sizeOfTxt = [marksizeWithFont:textFont
constrainedToSize:CGSizeMake(128,30)];
}

}
else
{

size =45;
textFont = [UIFontsystemFontOfSize:size];
sizeOfTxt = [marksizeWithFont:textFont
constrainedToSize:CGSizeMake(self.frame.size.width,30)];
while (sizeOfTxt.width>w) {
size ++;
textFont = [UIFontsystemFontOfSize:size];
sizeOfTxt = [marksizeWithFont:textFont
constrainedToSize:CGSizeMake(self.frame.size.width,30)];
}

}

UIGraphicsBeginImageContext(img.size);
[[UIColorredColor]
set];
[imgdrawInRect:CGRectMake(0,0, w,
h)];
[markdrawInRect:CGRectMake((w-sizeOfTxt.width)/2,(h-sizeOfTxt.height)/2,
sizeOfTxt.width, sizeOfTxt.height)withFont:textFont];

UIImage *aimg =UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();
return aimg;
}

- (void)pan:(UIPanGestureRecognizer *)pan {
CGPoint currentPoint = [pan
locationInView:self];
CGPoint midPoint =
midpoint(previousPoint, currentPoint);

NSLog(@"获取到的触摸点的位置为--currentPoint:%@",NSStringFromCGPoint(currentPoint));

CGFloat viewHeight =
self.frame.size.height;
CGFloat currentY = currentPoint.y;

if (pan.state ==UIGestureRecognizerStateBegan) {
[pathmoveToPoint:currentPoint];

} elseif (pan.state
==UIGestureRecognizerStateChanged) {

[pathaddQuadCurveToPoint:midPoint
controlPoint:previousPoint];

}

if(0 <= currentY && currentY <= viewHeight)
{
if(max ==
0&&min ==
0)
{
max = currentPoint.x;
min = currentPoint.x;
}
else
{
if(max <= currentPoint.x)
{
max = currentPoint.x;
}
if(min>=currentPoint.x)
{
min = currentPoint.x;
}
}

}

previousPoint = currentPoint;

[selfsetNeedsDisplay];
}

- (void)drawRect:(CGRect)rect
{

self.backgroundColor = [UIColorwhiteColor];

[[UIColorblackColor]
setStroke];
[pathstroke];

self.layer.cornerRadius =5.0;

self.clipsToBounds =YES;

self.layer.borderWidth =0.5;
self.layer.borderColor = [[UIColorgrayColor]
CGColor];

CGContextRef context =UIGraphicsGetCurrentContext();

if(!isSure)
{

NSString *str =
@"请绘制签名";
CGContextSetRGBFillColor (context,
108/255,
108/255,108/255,
0.3);//设置填充颜色
CGRect rect1 =
CGRectMake((rect.size.width -StrWidth)/2, (rect.size.height
-StrHeight)/2-5,StrWidth,
StrHeight);
origionX = rect1.origin.x;
totalWidth = rect1.origin.x+StrWidth;

UIFont *font = [UIFontsystemFontOfSize:25];//设置字体
[strdrawInRect:rect1
withFont:font];
}
else

{
isSure =
NO;
}

}

- (void)clear
{
max =
0;
min =
0;

path = [UIBezierPathbezierPath];

[pathsetLineWidth:2];

[selfsetNeedsDisplay];
}
- (void)sure
{

//没有签名发生时
if(min ==
0&&max ==
0)
{
min =
0;
max =
0;
}
isSure =
YES;

[selfsetNeedsDisplay];

return [selfimageRepresentation];
}

@end

在根视图viewController里面代码如下：
.h文件

#import <UIKit/UIKit.h>

#import "signatureView.h"

@interface ViewController :UIViewController<GetSignatureImageDele>
{
UIImage *saveImage;
UIView *saveView;
}

@property (strong,nonatomic)
signatureView *signatureView;

@end

.h文件

@implementation ViewController

- (void)viewDidLoad {

[superviewDidLoad];

self.view.backgroundColor = [UIColorgrayColor];

self.signatureView = [[signatureViewalloc]
initWithFrame:CGRectMake(10,70,
300,
100)];

self.signatureView.backgroundColor = [UIColorwhiteColor];

self.signatureView.delegate =self;

self.signatureView.showMessage =@"完成";

[self.viewaddSubview:self.signatureView];

UIButton *button = [UIButtonbuttonWithType:UIButtonTypeCustom];

[button setTitle:@"重签"forState:UIControlStateNormal];

[button setTitleColor:[UIColorcolorWithHue:72saturation:106brightness:123alpha:0.7]forState:UIControlStateNormal];
[buttonsetFrame:CGRectMake(20,self.signatureView.frame.origin.y+120,130,
40)];

button.layer.cornerRadius =5.0;
button.clipsToBounds =YES;
button.layer.borderWidth =1.0;
button.titleLabel.font = [UIFontsystemFontOfSize:17];
button.layer.borderColor = [[UIColorblackColor]CGColor];

[button addTarget:selfaction:@selector(clear:)forControlEvents:UIControlEventTouchUpInside];
[self.viewaddSubview:button];

UIButton *button2 = [UIButtonbuttonWithType:UIButtonTypeCustom];

[button2 setTitle:@"确认"forState:UIControlStateNormal];

[button2 setTitleColor:[UIColorwhiteColor]
forState:UIControlStateNormal];
button2.titleLabel.font = [UIFontsystemFontOfSize:17];
button2.backgroundColor = [UIColorblueColor];
[button2setFrame:CGRectMake(170,self.signatureView.frame.origin.y+120,130,
40)];
button2.layer.cornerRadius =5.0;
button2.clipsToBounds =YES;

[button2 addTarget:selfaction:@selector(add:)forControlEvents:UIControlEventTouchUpInside];
[self.viewaddSubview:button2];

saveView = [[UIViewalloc]
initWithFrame:CGRectMake(10, button2.frame
.origin.y+60,300,
140)];

saveView.backgroundColor = [UIColorlightGrayColor];
[self.viewaddSubview:saveView];

// Do any additional setup after loading the view, typically from a nib.
}
- (void)add:(UIButton *)sender
{

[self.signatureViewsure];

}

- (void)clear:(UIButton *)sender
{
NSLog(@"重签");

[self.signatureViewclear];
for(UIView *viewin
saveView.subviews)
{

[view removeFromSuperview];
}
}

-(void)getSignatureImg:(UIImage*)image
{
if(image)
{

NSLog(@"haveImage");

UIImageView *image1 = [[UIImageViewalloc]
initWithImage:image];

image1.frame =CGRectMake((saveView.frame.size.width-image.size.width)/2,
(saveView.frame.size.height-image.size.height)/2,
image.size.width, image.size.height) ;
[saveViewaddSubview:image1];

saveImage = image;
[selfsaveImage:saveImage];

//[self makeUpLoad];

}
else
{
NSLog(@"NoImage");

}

}

//图片保存到本地
- (void)saveImage:(UIImage *)image
{

//设置图片名

NSDateFormatter *dateFormatter = [[NSDateFormatteralloc]
init];
[dateFormattersetDateFormat:@"yyyyMMdd"];
NSString *currentDateStr = [dateFormatter
stringFromDate:[NSDate
date]];
NSString *dateStr = [NSStringstringWithFormat:@"%@.png",currentDateStr];

NSString *path = [NSTemporaryDirectory()stringByAppendingFormat:@"%@",dateStr];

BOOL existed = [[NSFileManagerdefaultManager]
fileExistsAtPath:pathisDirectory:nil];
if ( existed )
{

[[NSFileManagerdefaultManager]
removeItemAtPath:patherror:nil];
}
NSData *imgData =
UIImageJPEGRepresentation(image,
1);
[imgDatawriteToFile:path
atomically:YES];

}

- (void)didReceiveMemoryWarning {

[superdidReceiveMemoryWarning];

// Dispose of any resources that can be recreated.
}

效果图：