如何在ViewController类范围之外执行[self.view addSubview：lbl] [英] How to perform a [self.view addSubview: lbl] outside of ViewController Class scope?

问题描述

如何在ViewController类范围之外执行[self.view addSubview：lbl]？

或：

如何在不同类别的ViewController类外的mainview中添加标签或其他视图？

感谢

   - （void）viewDidLoad {
 [super viewDidLoad]; 
 
 UILabel * lbl = [[UILabel alloc] initWithFrame：CGRectMake（0，0，100，100）]; 
 [lbl setText：@hi there]; 
 
 [self.view addSubview：lbl]; //<  -  this works，but ... 
 //什么是self指的是？ 
 //如何声明和调用另一个类？ 
 
 ... 
 
 
 UILabel * lbl = [[UILabel alloc] initWithFrame：CGRectMake（0，0，100，100）]; 
 [lbl setText：@hi there]; 
 
 calcRomanAppDelegate * v = [[calcRomanAppDelegate new] init]; 
 [v.viewController.view addSubview：lbl]; // this compiles，but ... 
 //未能在表单上显示标签
 
 ... 
 
 
 UILabel * lbl = [[UILabel alloc] initWithFrame：CGRectMake（0，0，100，100）]; 
 [lbl setText：@hi there]; 
 
 calcRomanViewController * v = [[calcRomanViewController new] init]; 
 [v.view addSubview：lbl]; //这只是回调viewDidLoad ...无限循环
 
} 
  

c> c> c> c> c> 。假设你有 UIViewController * controller 变量在某处，你可以使用

  [controller.view addSubview：subview] 
  

How to perform a [self.view addSubview: lbl] outside of ViewController Class scope ?

or:

How do I add a label or another view in the mainview, outside of the ViewController class, in a different class?

thanks

- (void)viewDidLoad { 
    [super viewDidLoad]; 

    UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 100, 100)]; 
    [lbl setText:@"hi there"];

    [self.view addSubview:lbl];// <-- this works, but ...
        // what is "self" referring to? 
        // and how can I declare and call from another class? 

    ...


    UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 100, 100)]; 
    [lbl setText:@"hi there"];

    calcRomanAppDelegate *v = [[calcRomanAppDelegate new] init]; 
    [v.viewController.view addSubview:lbl]; // this compiles, but...
         // fails to shows a label on the form

     ...


    UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 100, 100)]; 
    [lbl setText:@"hi there"];

    calcRomanViewController *v = [[calcRomanViewController new] init];
    [v.view addSubview:lbl]; // this just makes a call back to viewDidLoad... endless loop

}

解决方案

Well, view is just a property of the UIViewController class. Assuming that you have your UIViewController *controller variable somewhere, you can just use

[controller.view addSubview:subview]

这篇关于如何在ViewController类范围之外执行[self.view addSubview：lbl]的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！