在 ipad 应用程序中绘制签名并将其转换为图像

Posted 2023-03-12

【中文标题】在 ipad 应用程序中绘制签名并将其转换为图像

【英文标题】：Drawing signature in ipad app and convert it in image

【发布时间】：2013-08-29 06:21:38

【问题描述】：

我在 ipad 应用程序中绘制签名它工作正常但问题是当它保存图像时它还保存了 signatureView 的边框我只想保存绘图区域不完整的 signatureView 这是我的代码

  signatureView=[[UIView alloc] initWithFrame:CGRectMake(100,100,800,500)];
signatureView.backgroundColor=[UIColor colorWithRed:242.0/255.f green:242/255.0f blue:242/255.0f alpha:1];


signatureView.layer.borderWidth =4;
signatureView.layer.borderColor = [UIColor colorWithRed:23.0/255.0f green:190/255.0f blue:210/255.0f alpha:1].CGColor;
signatureView.layer.cornerRadius=30;




[self.view addSubview:signatureView];



UIButton*OkButton = [UIButton buttonWithType:UIButtonTypeCustom];
   [OkButton setFrame:CGRectMake(320,448,118,49)];
    [OkButton setTitle:@"OK" forState:UIControlStateNormal];

[OkButton setImage:[UIImage imageNamed:@"okT.png"] forState:UIControlStateNormal];


   [OkButton addTarget:self action:@selector(onOKButtonClick) forControlEvents:UIControlEventTouchUpInside];
[signatureView addSubview:OkButton];

UILabel*textLabel=[[UILabel alloc] initWithFrame:CGRectMake(20,6,300,50)];

textLabel.font=[UIFont fontWithName:@"Helvetica-Bold" size:16];
textLabel.text=@"Use the touchscreen to sign here";
textLabel.backgroundColor=[UIColor clearColor];
textLabel.textColor=[UIColor grayColor];    
[signatureView addSubview:textLabel];


    drawScreen=[[MyLineDrawingView alloc]initWithFrame:CGRectMake(10,50,780,400)];
    [signatureView addSubview:drawScreen];
    [drawScreen release];


    //MyLineDrwaingView


   @interface MyLineDrawingView : UIView 

    UIBezierPath *myPath;
    UIColor *brushPattern;
   

  @end


    #import "MyLineDrawingView.h"


    @implementation MyLineDrawingView

    - (id)initWithFrame:(CGRect)frame
  

   self = [super initWithFrame:frame];
   if (self) 
    // Initialization code

    self.backgroundColor=[UIColor whiteColor];
    myPath=[[UIBezierPath alloc]init];
    myPath.lineCapStyle=kCGLineCapRound;
    myPath.miterLimit=0;
    myPath.lineWidth=10;
    //brushPattern=[UIColor redColor];
    brushPattern=[UIColor blackColor];

         
        return self;
     


    // Only override drawRect: if you perform custom drawing.
    // An empty implementation adversely affects performance during animation.
    - (void)drawRect:(CGRect)rect
   

     [brushPattern setStroke];
     [myPath strokeWithBlendMode:kCGBlendModeNormal alpha:1.0];
     

    #pragma mark - Touch Methods

   -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
  

   UITouch *mytouch=[[touches allObjects] objectAtIndex:0];
   [myPath moveToPoint:[mytouch locationInView:self]];

   

  -(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event

  

   UITouch *mytouch=[[touches allObjects] objectAtIndex:0];
  [myPath addLineToPoint:[mytouch locationInView:self]];
   [self setNeedsDisplay];

  


 -(void)onOKButtonClick 
 CGRect rect = [drawScreen bounds];   //use your signature view's Rect means Frame;
 UIGraphicsBeginImageContext(rect.size);
 CGContextRef context = UIGraphicsGetCurrentContext();
 [signatureView.layer renderInContext:context];   //this line is also important for you
 UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    signImageView.image = img;
 

【参考方案1】：

我已经在我的代码中实现了它对我的工作：

.h文件添加UIGestureRecognizerDelegate

.m 字段

-(void)scrollGesture:(UIGestureRecognizer *)sender


    CGPoint touchLocation = [sender locationInView:scrollView];

    NSLog(@"%d %d %d %d",touchLocation.y > signatureViewOne.frame.origin.y,touchLocation.y < signatureViewOne.frame.origin.y+80,touchLocation.x > 3, touchLocation.x < 308);
    if ((touchLocation.y > signatureViewOne.frame.origin.y && touchLocation.y < signatureViewOne.frame.origin.y+80) &&(touchLocation.x > 3 && touchLocation.x < 308))
    
        NSLog(@"Signone found");
        scrollView.scrollEnabled = NO;

    
    else

    if ((touchLocation.y > signatureViewTwo.frame.origin.y && touchLocation.y < signatureViewTwo.frame.origin.y+80) &&(touchLocation.x > 3 && touchLocation.x < 308))
    
        NSLog(@"SignTwo found");
        scrollView.scrollEnabled = NO;

    
    else
    
        NSLog(@"not found");
        scrollView.scrollEnabled = YES;
        sender.enabled = YES;
    


 

【参考方案2】：

这个 SO 主题有完全相同的问题（在 ios 上绘制和保存签名）：iOS: How to convert the self-drawn content of an UIView to an image (widespread general solution returns blank image)?

如果有帮助，请尝试将您的问题标记为已解决。