IOS Proxy Transfer value

Description: The proxy pass value is generally used in the reverse pass value.

The example of this post is: There is a and B two interface, to achieve the effect is to let a jump to B, then B has a color parameter, when B jumps to a, the color of the parameter to a, in a to use this color to change the color of their interface.

1th step: In the sender (interface B), the establishment of an agreement (declared in the. h header File)

The protocol name usually begins with the class name of this class +delegate (contains prefix)

@protocol configviewcontrollerdelegate

Declares the protocol method, usually beginning with the class name (no prefix required)

-(void) Changebgcolor: (Uicolor *) color;

2nd Step: The agent protocol in the. h file in the sender (interface B).

@interface Configviewcontroller:uiviewcontroller

ID means who can set up to be my agent

@property (nonatomic,weak) ID delegate;

ARC uses WEAK,MRC with assign

@end

3rd Step: Notify the agent (the most important step ) in the method in the sender (interface B)

This step is generally implemented in the method of jump to a in B, I created a button in B, so that the notification agent in the button jump method implemented.

if ([Self.delegate respondstoselector: @selector (changebgcolor:)]) {

Adding an If statement is to first determine whether there is a changebgcolor in interface A, and when this method is used, the proxy value is passed.

In general, a color object is instantiated first, and it is passed with this color when the value of the proxy is transferred.

[Self.delegate Changebgcolor:color];

The self here is the interface B,self.delegate is interface a (set in steps 4th and 5th)

}

4th step: Abide by the protocol in the recipient (interface a).

@interface Viewcontroller ()

5th step: Set yourself as the agent in the recipient (interface a).

Configviewcontroller *TESTVC = [[Configviewcontroller alloc] init];

Testvc.delegate = self;

6th step: Implement the method in the protocol in the recipient (interface a).

-(void) Changebgcolor: (Uicolor *) color{

Self.view.backgroundColor = color;

}

IOS Proxy Transfer value