Question

我的主视图上有一个标签。我有一个按钮，可以将我带到另一个视图。在它上面我有一个按钮来改变我在主视图上的标签。

我该怎么做？我加了一个项目，请有人帮帮我...

项目：here

Answer 1

我通常使用委托协议：

在第二个视图中添加：

@protocol viewControllerDelegate;

@interface viewController : UIView  

id < viewControllerDelegate > delegate;  
@property (nonatomic, assign) id < QuickViewControllerDelegate > delegate;

@end

@protocol viewControllerDelegate

- (void)viewController:(ViewController *)controller stringForLabel:(NSString*)string; 

@end

在第二个视图m文件调用中：

[delegate quickViewController:self
stringForLabel:@"your string"];

在主视图h文件中添加：，类似：

 @interface MainView:UIViewController<viewControllerDelegate>

主视图m文件中的

：

首先：当你初始化第二个视图时，不要忘记添加：

secondview.delegate = self;

另外，它不会工作。

第二：添加委托功能：

 - (void)viewController:(ViewController*)controller stringForLabel:(NSString*)string{

    //set the label from the string passed

    lable.text = string;

    }

希望它会有所帮助 SHANI

Answer 2

O.K我通常不这样做，但现在......

这是我更改后的文件 -

View1 .h （尝试使用大写字母命名这些文件）;

 #import <UIKit/UIKit.h>

@protocol View1Delegate;


@interface View1 : UIViewController {

    id <View1Delegate> delegate;
    IBOutlet UIButton *btn_changelbl;
    IBOutlet UIButton *btn_back;
}

@property (nonatomic, assign) id <View1Delegate> delegate;
@property (nonatomic,retain) IBOutlet UIButton *btn_changelbl;
@property (nonatomic,retain) IBOutlet UIButton *btn_back;

-(IBAction) backToMain:(id)sender;
-(IBAction) changeLabel:(id)sender;
@end


@protocol View1Delegate 
- (void)view1:(View1*)controller labelNeedsChage:(BOOL)needsChange stringForLabel:(NSString*)string;

@end

<强> View1.m

#import "View1.h"
#import "testViewController.h"

@implementation View1
@synthesize delegate;
@synthesize btn_changelbl;
@synthesize btn_back;

-(IBAction) backToMain:(id)sender {
    [self dismissModalViewControllerAnimated:YES];
    [delegate view1:self labelNeedsChage:NO stringForLabel:nil];

}

-(IBAction) changeLabel:(id)sender{
    [delegate view1:self labelNeedsChage:YES stringForLabel:@"new text"];
    [self dismissModalViewControllerAnimated:YES];
}

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
    [super viewDidUnload];

}


- (void)dealloc {
    [btn_changelbl release];
    [btn_back release];
    [super dealloc];
}


@end

<强> TestViewController.h

#import <UIKit/UIKit.h>
#import "View1.h"

@interface testViewController : UIViewController<View1Delegate> {

    IBOutlet UILabel *lb_test;
    IBOutlet UIButton *btn_changeView;

}

@property (nonatomic,retain) IBOutlet UILabel *lb_test;
@property (nonatomic,retain) IBOutlet UIButton *btn_changeView;

-(IBAction) changeView:(id)sender;
@end

<强> TestViewController.m

#import "testViewController.h"
#import "view1.h"

@implementation testViewController

@synthesize lb_test;
@synthesize btn_changeView;

-(IBAction) changeView:(id)sender {
    View1 *myView = [[View1 alloc] init];
    myView.delegate=self;
    [self presentModalViewController:myView animated:YES];
}


- (void)view1:(View1*)controller labelNeedsChage:(BOOL)needsChange stringForLabel:(NSString*)string{
    if(needsChange){
        lb_test.text=string;
    }

}


- (void)dealloc {
    [lb_test release];
    [btn_changeView release];
    [super dealloc];
}

@end

多数民众赞成。顺便说说：你有很多我犯过的小错误。查看修复程序以尝试理解它们。

从另一个视图更改标签

2 个答案: