objective-c - 收到此警告：使用类型为“*”的表达式初始化“*”的不兼容指针类型

Question

我收到此警告，但不知道我做错了什么，这是一个简单的代码，可以通过转换更改视图。我以前在 Xcode 3.x 中没有出现此错误，但现在在 4.x 中问题开始了。尽管这只是一个警告并且代码可以完美编译，但我想知道问题出在哪里。

-(IBAction)swapViews:(id)sender{
DemoViewController *view3 = [[ThirdViewController alloc] initWithNibName:@"ThirdViewController" bundle:nil];
view3.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self presentModalViewController:view3 animated:YES];}

感谢您的所有帮助

Answer 1

 //DemoViewController*   ThirdViewController*   ????
 //the warning is in this line 
DemoViewController *view3 = [[ThirdViewController alloc] initWithNibName:@"ThirdViewController" bundle:nil];
view3.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self presentModalViewController:view3 animated:YES];

我想你想在这里做的是。

ThirdViewController *view3 = [[ThirdViewController alloc] initWithNibName:@"ThirdViewController" bundle:nil];

Answer 2

你忘了花括号吗？

-(IBAction)swapViews:(id)sender {
    DemoViewController *view3 = [[ThirdViewController alloc] initWithNibName:@"ThirdViewController" bundle:nil];
    view3.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
    [self presentModalViewController:view3 animated:YES];
}