iOS传值方法

传值：

1>单例传值：

(1)发送方：((AppDelegate *)[UIApplication sharedApplication].delegate).color=[UIColor orangeColor];

接收方： UIColor * color=((AppDelegate *)[UIApplication sharedApplication].delegate).color;

self.view.backgroundColor=color;

//必须在AppDelegate声明一个属性@property (retain) UIColor * color;

（2）先建一个类继承NSObject实现一个+方法并且要声明它传值的属性

DataCenter.h:

+(DataCenter *)sharedDC;

@property (copy) NSString * userName;

@property (copy) NSString * password;

DataCenter.m:

+(DataCenter *)sharedDC

{

4000

static DataCenter * theDataCenter=nil;

if (theDataCenter==nil) {

theDataCenter=[[DataCenter alloc]init];

}

return theDataCenter;

}

发送方：DataCenter * theDC=[DataCenter sharedDC];

theDC.userName=_userNameTF.text;

theDC.password=_passwordTF.text;

接收方：

NSString * userName=[DataCenter sharedDC].userName;

NSString * password=[DataCenter sharedDC].password;

_userInfoLab.text=[NSString stringWithFormat:@”用户名:%@\n用户密码:%@”,userName,password];

2>代理传值：

先遵守一个ChangeColor协议：-(void)itIsTimeToChangeColor:(UIColor *)color;

发送方：if ([self.delegate respondsToSelector:@selector(itIsTimeToChangeColor:)]) {

[self.delegate itIsTimeToChangeColor:color];

}

但必须设置个属性：@property (assign) id delegate;

接收方：-(void)itIsTimeToChangeColor:(UIColor *)color{

self.view.backgroundColor=color;

}但必须遵守协议

3>广播传值：

发送方： //发送一个广播，广播携带参数

[[NSNotificationCenter defaultCenter]postNotificationName:@”changColor” object:oneColor];

接收方： [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(needChangeColor:) name:@”changColor” object:nil];

-(void)needChangeColor:(NSNotification *)notification{

UIColor * color=notification.object;

self.view.backgroundColor=color;

}

4>block传值：

先在发送方声明block属性：有参返回值与无参返回值（下面是带参有参返回值）

typedef UIColor (^block)(UIColor );

发送方：

UIColor * redColor=[UIColor redColor];

UIColor * color1= self.Handle(redColor);

self.view.backgroundColor=color1

接收方：

secondViewController * secondVC=[[secondViewController alloc]init];

secondVC.Handle=^(UIColor * color){

self.view.backgroundColor=color;

return _greenColor;

};