无法在屏幕上显示文本字段

Question

I added a text field in viewDidLoad but it did not show up on screen.

Here's .h

#import <UIKit/UIKit.h>
@interface SecondViewController : UIViewController{
    UITextField *tfText;
}
@property (nonatomic, retain) UITextField *tfText;
@end

Here's .m

- (void)viewDidLoad{
    [super viewDidLoad];    

    [self.view setBackgroundColor:[UIColor lightGrayColor]];

    tfText.frame = CGRectMake(65, 100, 200, 50);
    tfText.backgroundColor = [UIColor whiteColor];    
    [tfText setTextColor:[UIColor blackColor]];
    tfText.placeholder = @"Test";
    [tfText setBorderStyle:UITextBorderStyleNone];
    [self.view addSubview:tfText]; 
}

Answer 1

seems that you need to initialize the object... I mean

UITextField *newTextField = [[UITextField alloc] init];
self.tfText = newTextField;
//....
//all your code here
//....
[newTextField release];

And dont forget to release your instance on dealloc method.

Answer 2

D33pN16h7 is correct, you need to instantiate your object. However I would do it a little differently than described above, there is no reason to create a UITextField instance, and then set your instance to it.

self.tfText = [[UITextField alloc] init];

Answer 3

    UITextField entered2 = [[UITextField alloc] initWithFrame:CGRectMake(120.0, 125.0, 150.0, 25.0)]; 
[entered2 setBackgroundColor:[UIColor whiteColor]]; 
entered2.text=@"Active";    
[self.view addSubview:entered2];
[entered2 release];