ios中view和view的传值（NSUserDefaults和通知中心）

来源：互联网发布：淘宝小号怎么快速上心编辑：程序博客网时间：2024/06/18 06:37

原文地址： http://blog.csdn.net/gyz413977349/article/details/38333951

1、利用NSUserDefaults来传值，这种方法只限于传少量数据的情形：

比如你要传一个float的值，在需要传的时候用

[[NSUserDefaults standardUserDefaults] setFloat:float forKey::@”float”]

接收值的时候用

[[NSUserDefaults standardUserDefaults] floatForKey:@”float”]

2、NSNotificationCenter来传值

(void)touchesEnded:(NSSet )touches withEvent:(UIEvent )event

{

UITouch * touch = [touches anyObject];CGPoint point = [touch locationInView:self];CGRect roundRect = [self rectNeedRefreshFromThisPoint:point];mLastPoint = CGPointMake(-1, -1);NSLog(@"%s: point(%f,%f)", __FUNCTION__, point.x, point.y);[self addToCurrentLineWithPoint:point.x y:point.y];[self endLine];[self setNeedsDisplayInRect:roundRect];NSNumber *pointX = [NSNumber numberWithFloat:point.x];NSNumber *pointY = [NSNumber numberWithFloat:point.y];NSDictionary *pointDict = [NSDictionary dictionaryWithObjectsAndKeys:pointX,@"pointX",pointY,@"pointY", nil];[[NSNotificationCenter defaultCenter]postNotificationName:@"passTouchedEndPointMsg" object:self userInfo:pointDict];

}

在消息中心的函数：

[[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(getTouchedPoint:)                                                 name:@"passTouchedEndPointMsg"                                               object:nil];

(void) getTouchedPoint

:(NSNotification *)noti

{

NSDictionary *pointDict = [noti userInfo];touchedEndPointX = [[pointDict objectForKey:@"pointX"] floatValue];touchedEndPointY = [[pointDict objectForKey:@"pointY"] floatValue];NSLog(@"%f:%f",touchedEndPointX,touchedEndPointY);

}

用消息来传参数有下面几点说法：object指的是发送者、在poseter端的userInfo里面可以存放要传的参数，必须为NSDictionary类型。在center端获取这个dictionary类型用:[notification userInfo];来获取

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