Question

如果我有

UITapGestureRecognizer *tapped = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(somefunction:)];

-(void)somefunction :(id) sender{}

将变量传递给某个函数的正确语法是什么？我试过了（但它不起作用）

UITapGestureRecognizer *tapped = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(somefunction: somensstring:)];

-(void)somefunction: (NSString *) somestuff :(id) sender{}

Answer 1

//添加点按手势

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(HandleTap:)];

//在TableView中获取TouchLocation

-(void)HandleTap:(UITapGestureRecognizer*)tap
{
    CGPoint point = [tap locationInView:theTableView];

    NSIndexPath *theIndexPath = [theTableView indexPathForRowAtPoint:point];
}

你可以根据tableView From Array的indexPath获得你想要的任何信息;

Answer 2

您应该以这种方式定义somefunction方法，

-(void)somefunction:(UIGestureRecognizer *) sender {};

简单方法

-(void)somefunction:(UIGestureRecognizer *) sender {
    UIView *view = (UIView *)sender.view; 
    //1.here you can take any view, UILabel, UIImageView or anything on which you've 
    //added tap gesture

    //2.now, distinguish view by tag
    if(view.tag == someTag1) {
        //create a NSString to use when tap
    }
    else if(view.tag == someTag2) {
        //do something else
    }
};

让它变得有点复杂

定义相同的方法（如上所述）但是您从识别器中获取的视图，使其成为子类。
例如如果您在UILabel上设置了点按手势，则创建UILabel的子类，然后在其上添加手势。
还要为该子类添加所需的属性。
在向其添加手势时，还要为其设置变量（或任何内容）。
当用户点击时，它仍可供您使用。

这里是UILabel子类的例子，

@interface MyCustomLabel : UILabel 
@property (nonatomic, strong) NSString *someString;
@end;

现在您可以使用此自定义标签，

#import "MyCustomLabel.h"

MyCustomLable *lbl = [[MyCustomLable alloc] init];
lbl.frame = CGRectMake(0,0,200,50);
//add gesture on label
lbl.someString = @"Some text";
[self.view addSubview:lbl];

现在上面的方法几乎没有变化，

-(void)somefunction:(UIGestureRecognizer *) sender {
    MyCustomLabel *lbl = (MyCustomLabel *)sender.view; 
    NSLog(@"My String %@",lbl.someString);
};

如何在@selector（目标c）中传递变量？

2 个答案:

简单方法

让它变得有点复杂