我认为我在分配segmentcontrol时犯了一些错误。我遇到了一个错误[无法识别的选择器发送到实例]

Question

    Segcontrol = [[UISegmentedControl alloc] initWithItems:[NSArray arrayWithObjects:@"Mind", @"Munches", nil]];
    Segcontrol.frame=CGRectMake(CGRectGetWidth(self.view.frame)/4.5, self.view.frame.size.height/4, CGRectGetWidth(self.view.frame)/1.8, CGRectGetHeight(self.view.frame)/12);
    [Segcontrol addTarget:Segcontrol action:@selector(segtap:) forControlEvents:UIControlEventValueChanged];
    [Segcontrol setSelectedSegmentIndex:0];
    [Segcontrol setTintColor:[UIColor blueColor]];
    Segcontrol.layer.cornerRadius=5;
    [self.view addSubview:Segcontrol];


-(void)segtap:(id)sender{
    if (Segcontrol.selectedSegmentIndex==0) {

        self.view.backgroundColor=[UIColor blueColor];


    }else if (Segcontrol.selectedSegmentIndex==1){

        self.view.backgroundColor=[UIColor redColor];


    }

}

Answer 1

You are adding the SegmentControl object Segcontrol as target to the segment action. Rather than this the object self should be added as target. Change the code like below and you are good to go.

[Segcontrol addTarget:self action:@selector(segtap:) forControlEvents:UIControlEventValueChanged];

Answer 2

Implement segtap method like this.

 -(void)segtap:(id)sender
 {
     switch (Segcontrol.selectedSegmentIndex)
     {
     case 0:
         NSLog(@"Index 0 selected");
         break;
     case 1:
        NSLog(@"Index 1 selected");
        break;
     }
 }

I think you might be forgotten to pass argument to the method.