ios - iPad 上的 I/O - 错误

Question

我的 iPad 应用程序中有以下按钮:

subject = [[UIButton alloc] init];
subject.frame = CGRectMake(710, 5, 180, 30);

[[subject layer] setCornerRadius:8.0f];
[[subject layer] setMasksToBounds:YES];
[[subject layer] setBorderWidth:3.0f];
[[subject layer] setBackgroundColor:[[UIColor greenColor] CGColor]];
subject.titleLabel.font = [UIFont boldSystemFontOfSize:20];
[subject setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
[subject setTitleColor:[UIColor whiteColor] forState:UIControlEventAllEvents];
[subject addTarget:self action:@selector(subjectPressed) forControlEvents:UIControlEventTouchUpInside];
[subject setTitle:@"Subject: ?" forState:UIControlStateNormal];
[[subject layer] setBorderColor:[[UIColor greenColor] CGColor]];
[self.view addSubview:subject];

这是当我单击按钮时调用的函数:- (void)subjectPressed {

UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"Subject" message:@"Please enter the Subject:" delegate:self cancelButtonTitle:@"Continue" otherButtonTitles:nil];
alert.tag = 0;
alert.alertViewStyle = UIAlertViewStylePlainTextInput;
UITextField * alertTextField = [alert textFieldAtIndex:0];
alertTextField.keyboardType = UIKeyboardTypeNumberPad;
alertTextField.placeholder = @"Enter Subject";
[alert show];

}

当我单击按钮时，出现以下错误:

warning: Unable to read symbols for /Users/myname/Library/Developer/Xcode/iOS DeviceSupport/5.0.1 (9A405)/Symbols/System/Library/TextInput/Riven.bundle/Riven (file not found).
warning: No copy of Riven.bundle/Riven found locally, reading from memory on remote device.  This may slow down the debug session.

这是关于什么的？

Answer 1

尝试删除以下文件夹中的文件:

/Developer/Platforms/iPhoneOS.platform/DeviceSupport/

重新启动 Xcode 并重新插入 iPad。

另一个类似的问题:

warning: Unable to read symbols