objective-c - 在applicationDidBecomeActive中调用NSRunLoop方法导致系统无响应

Question

当我的 iOS 应用程序被激活时，单击应用程序支持的文件 (FTA) 时，我想在 applicationDidBecomeActive 中显示模态视图。因为我想要回控制权，所以当模态视图被关闭时，我使用 NSRunLoop 和一个标志来检测 View 是否被关闭。请参阅随附的代码。当调用 [NSRunloop runUntilDate] 时，我的 View 会显示，但位于当前 View 后面，并且不响应键盘/鼠标操作。任何想法发生了什么。

[代码]

- (void) applicationDidBecomeActive:(UIApplication *)application {


//App activated due to file selection in an email attachment, display modal dialog
if (fileSelected) 
{
    RSAImportViewController *s = [[RSAImportViewController alloc] initWithNibName:@"RSAImportViewController_iPad" bundle:nil];

    UINavigationController* rNC = [[UINavigationController alloc] initWithRootViewController:s];

    [rNC setModalPresentationStyle:UIModalPresentationFormSheet];
    [rNC setModalTransitionStyle:UIModalTransitionStyleCoverVertical];

    [nav presentModalViewController:rNC animated:YES];

// wait for modal view to be dismissed, the modal view is dismissed when ok/cancel
// buttons are clicked.

  while (s.completion == requestRunning) {
    [[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:1.0]];
}

[s dismissKeyboard];

// Do further processing

return;
}

Answer 1

这不是 NSRunLoop 方法的用途。

您应该将自己设置为模态视图的委托(delegate)，并让模态视图在其委托(delegate)被解除时通知其委托(delegate)，并根据需要调用任何其他方法来执行您想做的任何事情。

在 RSAImportViewController.h 中:

@class RSAImportViewController
@protocol RSAImportViewControllerDelegate
-(void)rsaImportViewControllerDone:(RSAImportViewController*)vc;
@end

@interface RSAImportViewController
...
@property(assign) id<RSAImportViewControllerDelegate> delegate;
@end

在 RSAImportViewController.m 中，无论您在何处调用 dismissModalViewControllerAnimated: 方法:

@implementation RSAImportViewController
@synthesize delegate;
...
-(void)someMethodInYourCode {
    ...
    [self dismissModalViewControllerAnimated:YES];
    // call the delegate method to inform we are done (adapt to your needs)
    [self.delegate rsaImportViewControllerDone:self];
}
...
@end

在 AppDelegate 中:

- (void) applicationDidBecomeActive:(UIApplication *)application {
{
    if (fileSelected) {
        ...
        rNC.delegate = self; // set 'self' to be informed when the rNC is dismissed
        [nav presentModalViewController:rNC animated:YES];
    } else {
        [self doFurtherProcessing];
    }
}
-(void)rsaImportViewControllerDone:(RSAImportViewController*)vc {
    [self doFurtherProcessing];
}
-(void)doFurtherProcessing {
    [s dismissKeyboard];
    // and all your other stuff
}