Question

我正在尝试使用NSUndoManager实现撤消/重做方法。我已经就此提出了其他问题，但我仍然陷入困境。

我现在所处的位置如下：

.h
NSUndoManager *undoManager;
@property(nonatomic,retain) NSUndoManager *undoManager;

.m
@synthesize undoManager;

[undoManager setLevelsOfUndo：99]; viewDidLoad中：

NSNotificationCenter *dnc = [NSNotificationCenter defaultCenter];      
[dnc addObserver:self selector:@selector(undoButtonTapped) name:@"undo" object:nil];   
[dnc addObserver:self selector:@selector(redoButtonTapped) name:@"redo" object:nil];

- (void)resetTheImage:(UIImage*)image
{
    NSLog(@"%s", __FUNCTION__);

   // image = savedImage.image;
    if (image != drawImage.image)
    {
        [[undoManager prepareWithInvocationTarget:self] resetTheImage];
        image = drawImage.image ;        
    } else {
        NSLog(@"That didn't work");
    }
}

- (void)undoButtonTapped {
    NSLog(@"%s", __FUNCTION__);
    [undoManager undo];
}

我得到“那不起作用”......

我很感激帮助。当我弄清楚我做错了什么时，我会将答案发给我原来的问题。

--- --- EDIT

我更改了resetTheImage，如下所示：

- (void)resetTheImage:(UIImage*)image
{
    NSLog(@"%s", __FUNCTION__);

    image = savedImage.image;
    if (image != drawImage.image)
    {
        drawImage.image = image;
        savedImage.image = image;
        NSLog(@"undo image");
        [[self.undoManager prepareWithInvocationTarget:drawImage.image] image];        

    } else {
        NSLog(@"same image");
        savedImage.image = image;
    }
}

然而，混乱下雨 - 如果有人（布拉德？，贾斯汀？）可以提供我需要采取的步骤的子弹点列表，这可能会有所帮助。例如：

。在...中添加通知。触发通知.... 。撤消/重做按钮指向... 。我真正需要构建哪些方法/功能.. ....

我希望这会让我给你更多的积分而不是1 ..

（我的“o”键变硬了没有帮助）我确实帮助我昨天生了一个小孙女：））））

Answer 1

首先，我要感谢大家的任何/所有帮助。我终于解决了这个问题，虽然我不确定它是否是最好的解决方案。

我从UIViewController调用了一个UIView。控件（颜色和画笔）保留在VC中。绘图方法移至View方法。

View方法调用Drawing方法实际执行绘制，View方法控制撤消/重做。

以下是一些代码段：

-(void)undoButtonClicked
{
    //NSLog(@"%s", __FUNCTION__);
    if ([self.currentArray count] == 0) {
        //nothing to undo
        return;
    }

    DrawingPath *undonePath = [self.currentArray lastObject];
    [self.currentArray removeLastObject];
    [self.redoStack addObject:undonePath];
    [self setNeedsDisplay];

}

-(void)redoButtonClicked
{
    //NSLog(@"%s", __FUNCTION__);

    if ([self.redoStack count] == 0) {
        // nothing to redo
        return;
    }

    DrawingPath *redonePath = [self.redoStack lastObject];
    [self.redoStack removeLastObject];
    [self.currentArray addObject:redonePath];
    [self setNeedsDisplay];

}

如果有人想要澄清，请告诉我。再次感谢...

按要求更新：

这些是一些标题：

    DrawingViewController  *mvc;
    NSMutableArray *pathArray;
    NSMutableArray *colorArray;
    NSMutableArray *bufferArray;
    NSMutableArray *currentArray;
    UIBezierPath *myPath;
    NSString *brushSize;
    CGPoint lastPoint;
    int colorIndex;
    NSString *colorKey;

    SoundEffect         *erasingSound;
    SoundEffect         *selectSound;

    BOOL swiped;    
    int moved;
    UIColor *currentColor;
    NSString *result;
}
@property(nonatomic,assign) NSInteger undoSteps;
@property (strong, nonatomic) NSString *result;

@property (strong,nonatomic) UIColor *currentColor;
@property (strong,nonatomic) NSMutableArray *currentArray;
@property (strong,nonatomic) NSMutableArray *bufferArray;
@property (strong,nonatomic) DrawingPath *currentColoredPath;
@property (strong,nonatomic) NSMutableArray *redoStack;
@property (strong, nonatomic) NSString *colorKey;

这里有一些方法..然后，currentArray会在一堆堆栈中跟踪点，笔刷和颜色。撤消从堆栈中删除，并添加到可用于重做的临时堆栈中。

-(void)undoButtonClicked
{
    //NSLog(@"%s", __FUNCTION__);
    if ([self.currentArray count] == 0) {
        //nothing to undo
        return;
    }

    DrawingPath *undonePath = [self.currentArray lastObject];
    [self.currentArray removeLastObject];
    [self.redoStack addObject:undonePath];
    [self setNeedsDisplay];

}

-(void)redoButtonClicked
{
    //NSLog(@"%s", __FUNCTION__);

    if ([self.redoStack count] == 0) {
        // nothing to redo
        return;
    }

    DrawingPath *redonePath = [self.redoStack lastObject];
    [self.redoStack removeLastObject];
    [self.currentArray addObject:redonePath];
    [self setNeedsDisplay];

}


#pragma mark - Touch Methods
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{   
    //NSLog(@"%s", __FUNCTION__);
    self.currentColoredPath = [[DrawingPath alloc] init];
    [self.currentColoredPath setColor:self.currentColor];
    UITouch *touch= [touches anyObject];


    [self.currentColoredPath.path moveToPoint:[touch locationInView:self]];
    [self.currentArray addObject:self.currentColoredPath];
    // Remove all paths from redo stack
    [self.redoStack removeAllObjects];

    lastPoint = [touch locationInView:self];
    lastPoint.y -= 20;

    if ([touch tapCount] == 2) {
        [self alertOKCancelAction];

        return;
    }  


}



-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    //NSLog(@"%s", __FUNCTION__);
    UITouch *touch = [touches anyObject]; 
    [self.currentColoredPath.path addLineToPoint:[touch locationInView:self]];

    [self setNeedsDisplay];


    CGPoint currentPoint = [touch locationInView:self];
    currentPoint.y -= 20;


    lastPoint = currentPoint;

}

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    //NSLog(@"%s", __FUNCTION__);
    self.currentColoredPath = nil;
}

向核心图形绘制应用添加撤消/重做方法

1 个答案: