不顯示按鈕文本

Question

當我嘗試發佈以下代碼時，我的應用程序只顯示按鈕文本應該在的空矩形。我是xcode的初學者，我從其他教程中確定了這些代碼。

- (void)viewDidLoad { 
    [super viewDidLoad]; 

    UILabel *player1 = [[UILabel alloc]initWithFrame:CGRectMake(35, 120,130, 30)]; 
    [player1 setText:@"Player"]; 
    player1.layer.borderWidth = 1.0; 
    player1.layer.borderColor = [UIColor blackColor].CGColor; 
    player1.textAlignment = UITextAlignmentCenter; 
    [self.view addSubview: player1]; 

    UIButton *score1 = [[UIButton alloc]initWithFrame:CGRectMake(165, 120, 60, 30)]; 
    [score1 setTitle:@"0" forState:UIControlStateNormal]; 
    score1.layer.borderWidth = 1.0; 
    score1.layer.borderColor = [UIColor blackColor].CGColor; 
    [self.view addSubview: score1]; 


    UILabel *player2 = [[UILabel alloc]initWithFrame:CGRectMake(35, 150, 130, 30)]; 
    [player2 setText:@"Opponent"]; 
    player2.layer.borderWidth = 1.0; 
    player2.layer.borderColor = [UIColor blackColor].CGColor; 
    player2.textAlignment = UITextAlignmentCenter; 
    [self.view addSubview: player2]; 
} 

就像我說的，除了按鈕中的文字都顯示出來。

Answer 1

之所以按鈕看起來是空白的，因爲它的文本顏色爲白色實際。只要給它一個不同的顏色和0現在將顯示：

score1.layer.backgroundColor = [UIColor blackColor].CGColor; 

如果你不想改變按鈕的背景顏色，你可能要設置文本顏色：

[score1 setTitleColor:[UIColor blueColor] forState:UIControlStateNormal]; 

閱讀Question: [initWithFrame:frame] vs. [UIButton buttonWithType]，瞭解更多關於使用這些不同方法創建UIButton的信息。

Answer 2

的問題是你在建立按鈕的方式：

UIButton *score1 = [[UIButton alloc]initWithFrame:CGRectMake(165, 120, 60, 30)]; 

那不是你怎麼做。這樣做：

UIButton *score1 = [UIButton buttonWithType:UIButtonTypeSystem]; 
score1.frame = CGRectMake(165, 120, 60, 30); 

一切都會在那之後！