Question

我想在uiview上绘制一个随机设计就像我们正在画画笔画我想要用户触摸屏幕开始绘图。就好像他想写得好，而不是画画。如果他想制作鸭子或球，那么他就可以制作它。请帮助我。

Answer 1

试试这个。在此，您必须使用self.view.frame，无论我有myPic.Frame。

在标题文件中：

#import <Foundation/Foundation.h>

@interface DrawView : UIView {

    UIImage *myPic;

    NSMutableArray *myDrawing;

}

-(void)drawPic:(UIImage *)thisPic;

-(void)cancelDrawing;

@end

并在实施文件中：

#import "DrawView.h"

@implementation DrawView

-(void)drawPic:(UIImage *)thisPic {

    myPic = thisPic;

    [myPic retain];

    [self setNeedsDisplay];

}

- (void)drawRect:(CGRect)rect {

    float newHeight;

    float newWidth;

    if (!myDrawing) {

        myDrawing = [[NSMutableArray alloc] initWithCapacity:0];

    }

    CGContextRef ctx = UIGraphicsGetCurrentContext();

    if (myPic != NULL) {

        float ratio = myPic.size.height/460;

        if (myPic.size.width/320 > ratio) {

            ratio = myPic.size.width/320;

        }

        newHeight = myPic.size.height/ratio;

        newWidth = myPic.size.width/ratio;

        [myPic drawInRect:CGRectMake(0,0,newWidth,newHeight)];

    }

    if ([myDrawing count] > 0) {

        CGContextSetLineWidth(ctx, 5);

        for (int i = 0 ; i < [myDrawing count] ; i++) {

            NSArray *thisArray = [myDrawing objectAtIndex:i];

            if ([thisArray count] > 2) {

                float thisX = [[thisArray objectAtIndex:0] floatValue];

                float thisY = [[thisArray objectAtIndex:1] floatValue];

                CGContextBeginPath(ctx);

                CGContextMoveToPoint(ctx, thisX, thisY);

                for (int j = 2; j < [thisArray count] ; j+=2) {

                    thisX = [[thisArray objectAtIndex:j] floatValue];

                    thisY = [[thisArray objectAtIndex:j+1] floatValue];

                    CGContextAddLineToPoint(ctx, thisX,thisY);

                }

                CGContextStrokePath(ctx);

            }

        }

    }

}

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

    [myDrawing addObject:[[NSMutableArray alloc] initWithCapacity:4]];

    CGPoint curPoint = [[touches anyObject] locationInView:self];

    [[myDrawing lastObject] addObject:[NSNumber numberWithFloat:curPoint.x]];

    [[myDrawing lastObject] addObject:[NSNumber numberWithFloat:curPoint.y]];

}

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

    CGPoint curPoint = [[touches anyObject] locationInView:self];

    [[myDrawing lastObject] addObject:[NSNumber numberWithFloat:curPoint.x]];

    [[myDrawing lastObject] addObject:[NSNumber numberWithFloat:curPoint.y]];

    [self setNeedsDisplay];

}

- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {

    CGPoint curPoint = [[touches anyObject] locationInView:self];

    [[myDrawing lastObject] addObject:[NSNumber numberWithFloat:curPoint.x]];

    [[myDrawing lastObject] addObject:[NSNumber numberWithFloat:curPoint.y]];

    [self setNeedsDisplay];

}

-(void)cancelDrawing {

    [myDrawing removeAllObjects];

    [self setNeedsDisplay];

}

- (void)dealloc {

    [super dealloc];

    [myPic release];

    [myDrawing release];

}

@end

Answer 2

你必须让你的UIView成为上面的一个子类。在你的控制器class.m文件中，你必须添加并调用这两个方法。我希望这有效。

- （IBAction）明确{

[self.view cancelDrawing];

}

- （IBAction为）saveDrawing {

UIGraphicsBeginImageContext(self.view.bounds.size);

[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];

UIImage *finishedPic = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

UIImageWriteToSavedPhotosAlbum(finishedPic, self, @selector(exitProg:didFinishSavingWithError:contextInfo:), nil);

}

在uiview上绘制随机设计

2 个答案: