實作如下
1. 加入記錄的變數到PaintMaskViewController.h中
#import <UIKit/UIKit.h>
@interface PaintMaskViewController : UIViewController
{
BOOL isFirstPoint;
}
@property(nonatomic, retain) UIImageView* drawImage;
- (void) redraw;
@property (nonatomic) CGPoint lPoint;
@property (nonatomic) CGPoint cPoint;
@property (nonatomic) NSMutableArray *linePointsArray;
@property (nonatomic) NSMutableArray *drawLineSet;
@end
2. 在PaintMaskViewController.h中增加相關程式碼
#import "PaintMaskViewController.h"
@interface PaintMaskViewController ()
@end
@implementation PaintMaskViewController
int mouseMoved;
BOOL mouseSwiped;
CGPoint lastPoint;
CGPoint currentPoint;
@synthesize drawImage;
@synthesize linePointsArray;
@synthesize drawLineSet;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
linePointsArray = [[NSMutableArray alloc] init];
drawLineSet = [[NSMutableArray alloc] init];
isFirstPoint = NO;
[self setClearButton];
[self setRedrawButton];
[self setClearSetsButton];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
if(drawImage == nil) {
self.drawImage = [[UIImageView alloc] initWithImage:nil];
drawImage.frame = self.view.frame;
[self.view addSubview:drawImage];
[linePointsArray removeAllObjects];
}
isFirstPoint = YES;
mouseSwiped = NO;
UITouch *touch = [touches anyObject];
lastPoint = [touch locationInView:self.view];
[linePointsArray addObject:[NSValue valueWithCGPoint:lastPoint]]; // add a CGPoint
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
mouseSwiped = YES;
UITouch *touch = [touches anyObject];
currentPoint = [touch locationInView:self.view];
[self drawLine:1];
lastPoint = currentPoint;
[linePointsArray addObject:[NSValue valueWithCGPoint:lastPoint]]; // add a CGPoint
mouseMoved++;
if (mouseMoved == 10) {
mouseMoved = 0;
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
//Double click to clean the canvas
UITouch *touch = [touches anyObject];
currentPoint = [touch locationInView:self.view];
[drawLineSet addObject:linePointsArray]; // add a array to sets
linePointsArray = nil;
linePointsArray = [[NSMutableArray alloc] init];
}
- (void) drawLine:(int) move
{
UIGraphicsBeginImageContext(self.view.frame.size);
[drawImage.image drawInRect:CGRectMake(0, 0, drawImage.frame.size.width, drawImage.frame.size.height)];
CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5.0);
CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 0.0, 1.0, 0.0, 1.0);
CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
if (move == 1)
CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y);
else
CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
CGContextStrokePath(UIGraphicsGetCurrentContext());
drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
- (void)setClearButton // 動態產生一個的Button
{
UIButton *clearButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
//動態產生一個RoundedRect 形式的 Button
clearButton.frame = CGRectMake(100,50, 100, 50); // 大小
// [clearButton setCenter:CGPointMake(150, 50)];//位置放在x=150, y=50的位置
[clearButton addTarget:self action:@selector(drawClear) forControlEvents:UIControlEventTouchUpInside];
//設定Button動作呼叫的function在 onHelloActionButton,方式為按下
//_helloActionButton.= @"Action Button";
[clearButton setTitle:@"清除畫面" forState:UIControlStateNormal];
//將動態Button上放置Action Button這兩個字
[self.view addSubview:clearButton];
//將動態Button放到View上展出
}
- (void)setRedrawButton // 動態產生一個的Button
{
UIButton *redrawButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
//動態產生一個RoundedRect 形式的 Button
redrawButton.frame = CGRectMake(200, 50, 100, 50); // 大小
//[redrawButton setCenter:CGPointMake(250, 50)];//位置放在x=150, y=50的位置
[redrawButton addTarget:self action:@selector(redraw) forControlEvents:UIControlEventTouchUpInside];
//設定Button動作呼叫的function在 onHelloActionButton,方式為按下
//_helloActionButton.= @"Action Button";
[redrawButton setTitle:@"重繪" forState:UIControlStateNormal];
//將動態Button上放置Action Button這兩個字
[self.view addSubview:redrawButton];
//將動態Button放到View上展出
}
- (void)setClearSetsButton // 動態產生一個的Button
{
UIButton *clearSetsButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
//動態產生一個RoundedRect 形式的 Button
clearSetsButton.frame = CGRectMake(300, 50, 100, 50); // 大小
//[redrawButton setCenter:CGPointMake(250, 50)];//位置放在x=150, y=50的位置
[clearSetsButton addTarget:self action:@selector(clearSet) forControlEvents:UIControlEventTouchUpInside];
//設定Button動作呼叫的function在 onHelloActionButton,方式為按下
//_helloActionButton.= @"Action Button";
[clearSetsButton setTitle:@"清除記錄" forState:UIControlStateNormal];
//將動態Button上放置Action Button這兩個字
[self.view addSubview:clearSetsButton];
//將動態Button放到View上展出
}
- (void) clearSet
{
[drawLineSet removeAllObjects];
drawLineSet = nil;
drawLineSet = [[NSMutableArray alloc] init];
}
- (void) redraw
{
UIGraphicsBeginImageContext(self.view.frame.size);
[drawImage.image drawInRect:CGRectMake(0, 0, drawImage.frame.size.width, drawImage.frame.size.height)];
CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5.0);
CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 1.0, 0.0, 1.0, 1.0);
int count1 = [drawLineSet count];
if (count1 ==0)
return;
NSMutableArray *temp = [[NSMutableArray alloc] init];
for (int j=0;j<count1;j++){
temp = [ drawLineSet objectAtIndex:j];
NSValue *val = [temp objectAtIndex:0];
CGPoint p = [val CGPointValue];
CGContextMoveToPoint(UIGraphicsGetCurrentContext(), p.x, p.y);
int count = [temp count];
for (int i=1; i<count; i++)
{
val = [temp objectAtIndex:i];
p = [val CGPointValue];
CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), p.x, p.y);
}
CGContextStrokePath(UIGraphicsGetCurrentContext());
}
drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
- (void) drawClear
{
UIGraphicsBeginImageContext(self.view.frame.size);
[drawImage.image drawInRect:CGRectMake(0, 0, drawImage.frame.size.width, drawImage.frame.size.height)];
CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5.0);
// 清除畫面
CGContextClearRect(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, 1024, 768));
// 存回畫面
drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
@end
3. 結果顯示，重繪的線使用紫色。
