ios - UIAlertController 操作表在第二次调用时没有响应

Question

我有类似以下代码的内容。操作表在第一次出现时运行 doSomething OK(在按钮 IBAction 中)，但是当它第二次出现时，没有任何反应，操作表只是消失而没有调用 do something。有什么想法吗？

@implementation ...

- (void) setActions {
    UIAlertAction *opt1 = [UIAlertAction actionWithTitle:@"Option 1" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
            [self doSomething:@"opt1"];}];

    UIAlertAction *opt2 = [UIAlertAction actionWithTitle:@"Option 2"    style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
            [self doSomething:@"opt2"];}];

    UIAlertAction *opt3 = ...

    self.opt1 = opt1;
    self.opt2 = opt2;
    self.opt3 = opt3;

- (void) showActionSheet {

    ...
UIAlertController *selectAS = [UIAlertController alertControllerWithTitle:@"Select Options"
 message:@"msg" preferredStyle:UIAlertControllerStyleActionSheet];

    if (xyz) {                  
          [selectAS addAction:self.opt1];
          [selectAS addAction:self.opt2];
        }
    else{            
          [selectAS addAction:self.opt1];
          [selectAS addAction:self.opt3];                    
        }
   [self presentViewController:selectqAS 
    animated:YES completion:nil];
        }

- (void) doSomething: (NSString *) opt{



  ....
    }

Answer 1

很高兴我们帮助您启动并运行。我的猜测是您的方法在翻译中丢失了。您有相互交织的方法，这可能会导致混淆，特别是 self.opt1。根据我的评论，现在 iOS8 已经引入了 UIAlertController，它附带了完成处理程序，您应该相应地进行计划:如下所示:

-(IBAction)showActionSheet {
    UIAlertController *selectAS = [UIAlertController alertControllerWithTitle:@"Select Options" message:@"msg" preferredStyle:UIAlertControllerStyleActionSheet];

     UIAlertAction *opt1 = [UIAlertAction actionWithTitle:@"Option 1" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        //Don't have to call another method, just put your action 1 code here. This is the power of completion handlers creating a more structured outline
     }];

     UIAlertAction *opt2 = [UIAlertAction actionWithTitle:@"Option 2" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        //Don't have to call another method, just put your action 2 code here. This is the power of completion handlers creating a more structured outline
     }];

     UIAlertAction *opt3 = ...

     if (xyz) {
       [selectAs addAction:opt1];
       [selectAs addAction:opt2];
     } else {
       [selectAs addAction:opt1];
       [selectAs addAction:opt3];
     }        

     [self presentViewController:selectAs animated:YES completion:nil];

 }

更加简洁，并且实际上将 UIAlertController 用于预期目的，不需要调用其他方法。