簡介
現(xiàn)在很多項(xiàng)目在完善信息或者注冊信息的時(shí)候,或者支付這一方面,都希望用戶手寫簽名,這樣既可以保證是用戶親自簽名的,保證該記錄是用用戶操作的,而不是別人操作的.所以手寫簽字這個(gè)還是比較重要的.下面就是通過QuartzCore來繪制簽名.QuartzCore是iOS的核心動畫框架.
繪制
1定義一個(gè)結(jié)構(gòu)體
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staticCGPoint?midpoint(CGPoint?p0,CGPoint?p1)?{
return(CGPoint)?{
(p0.x?+?p1.x)?/2.0,
(p0.y?+?p1.y)?/2.0
};
}
2添加手勢
UIPanGestureRecognizer?*pan?=?[[UIPanGestureRecognizer?alloc]?initWithTarget:self?action:@selector(pan:)];
pan.maximumNumberOfTouches?=?pan.minimumNumberOfTouches?=1;
[self?addGestureRecognizer:pan];
3開始繪制
CGPoint?currentPoint?=?[pan?locationInView:self];
CGPoint?midPoint?=?midpoint(previousPoint,?currentPoint);
NSLog(@"獲取到的觸摸點(diǎn)的位置為--currentPoint:%@",NSStringFromCGPoint(currentPoint));
[self.currentPointArr?addObject:[NSValue?valueWithCGPoint:currentPoint]];
self.hasSignatureImg?=?YES;
CGFloat?viewHeight?=?self.frame.size.height;
CGFloat?currentY?=?currentPoint.y;
if(pan.state?==UIGestureRecognizerStateBegan)?{
[path?moveToPoint:currentPoint];
}elseif(pan.state?==UIGestureRecognizerStateChanged)?{
[path?addQuadCurveToPoint: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;
//記得調(diào)用,及時(shí)刷新視圖
[self?setNeedsDisplay];
4獲取繪制視圖,在進(jìn)行一系列處理就好
if(UIGraphicsBeginImageContextWithOptions?!=NULL)
{
UIGraphicsBeginImageContextWithOptions(self.bounds.size,NO,?[UIScreen?mainScreen].scale);
}else{
UIGraphicsBeginImageContext(self.bounds.size);
}
[self.layer?renderInContext:UIGraphicsGetCurrentContext()];
UIImage?*image?=UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//繪制成圖
image?=?[self?imageBlackToTransparent:image];
NSLog(@"width:%f,height:%f",image.size.width,image.size.height);
//截取圖片
UIImage?*img?=?[self?cutImage:image];
//壓縮圖片
self.SignatureImg?=?[self?scaleToSize:img];
5附上處理的方法
1.繪制成圖
-?(UIImage*)?imageBlackToTransparent:(UIImage*)?image
{
//?分配內(nèi)存
constintimageWidth?=?image.size.width;
constintimageHeight?=?image.size.height;
size_t??????bytesPerRow?=?imageWidth?*4;
uint32_t*?rgbImageBuf?=?(uint32_t*)malloc(bytesPerRow?*?imageHeight);
//?創(chuàng)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);
//?遍歷像素
intpixelNum?=?imageWidth?*?imageHeight;
uint32_t*?pCurPtr?=?rgbImageBuf;
for(inti?=0;?i?<?pixelNum;?i++,?pCurPtr++)
{
//????????if?((*pCurPtr?&?0xFFFFFF00)?==?0)????//將黑色變成透明
if(*pCurPtr?==0xffffff)
{
uint8_t*?ptr?=?(uint8_t*)pCurPtr;
ptr[0]?=0;
}
//改成下面的代碼，會將圖片轉(zhuǎn)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;*/
}
//?將內(nèi)存轉(zhuǎn)成image
CGDataProviderRef?dataProvider?=?CGDataProviderCreateWithData(NULL,?rgbImageBuf,?bytesPerRow?*?imageHeight,/*ProviderReleaseData**/NULL);
CGImageRef?imageRef?=?CGImageCreate(imageWidth,?imageHeight,8,32,?bytesPerRow,?colorSpace,
kCGImageAlphaLast?|?kCGBitmapByteOrder32Little,?dataProvider,
NULL,true,kCGRenderingIntentDefault);
CGDataProviderRelease(dataProvider);
UIImage*?resultUIImage?=?[UIImage?imageWithCGImage:imageRef];
//?釋放
CGImageRelease(imageRef);
CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
//?free(rgbImageBuf)?創(chuàng)建dataProvider時(shí)已提供釋放函數(shù)，這里不用free
returnresultUIImage;
}
2.截圖圖片
CGRect?rect?;
//簽名事件沒有發(fā)生
if(min?==0&&max?==0)
{
rect?=CGRectMake(0,0,0,0);
}
else//簽名發(fā)生
{
rect?=CGRectMake(min-3,0,?max-min+6,self.frame.size.height);
}
CGImageRef?imageRef?=CGImageCreateWithImageInRect([image?CGImage],?rect);
UIImage?*?img?=?[UIImage?imageWithCGImage:imageRef];
//添加水印
UIImage?*lastImage?=?[self?addText:img?text:self.showMessage];
CGImageRelease(imageRef);
[self?setNeedsDisplay];
3.壓縮
//壓縮圖片,最長邊為128(根據(jù)不同的比例來壓縮)
-?(UIImage?*)scaleToSize:(UIImage?*)img?{
CGRect?rect?;
CGFloat?imageWidth?=?img.size.width;
//判斷圖片寬度
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);
[img?drawInRect:rect];
UIImage*?scaledImage?=UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//此處注釋是為了防止該簽名圖片被保存到本地
//????UIImageWriteToSavedPhotosAlbum(scaledImage,nil,?nil,?nil);
[self?setNeedsDisplay];
returnscaledImage;
}
剩下的,都是一些細(xì)節(jié)問題,根據(jù)不同的項(xiàng)目進(jìn)行不同的修改就好.
自己做的demo效果
