我有這個非常簡單的代碼，或者至少我認爲它很簡單。爲什麼我得到一個黑色的框架，而不是選擇器？
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView {
CGRect rect = CGRectMake(0.0f, 20.0f, 320.0f, 216.0f);
UIPickerView *myPickerView = [[UIPickerView alloc] initWithFrame:rect];
self.view = myPickerView;
[myPickerView release];
}
我使用XCode運行一個基於普通視圖的模板。我可以看到loadView被調用，但是我得到一個黑框而不是UIPickerView。
我在做什麼錯了？
/donnib
試試這個：
UIView *contentView = [[UIView alloc] initWithFrame: [[UIScreen mainscreen] bounds]];
UIPickerView *pickerView = [[UIPickerView alloc] initWithFrame: CGRectZero];
CGSize pickerSize = [pickerView sizeThatFits: CGSizeZero];
pickerView.frame = [self pickerFrameWithSize: pickerSize];
[pickerView setShowsSelectionIndicator: YES];
[contentView addSubview: pickerView];
[pickerView release];
[self setView: contentView];
[contentView release];
取而代之的首要-loadView，你應該重寫-viewDidLoad。視圖加載後，您將創建選取器並將其添加爲視圖控制器擁有的視圖的子視圖。
- (void)viewDidLoad
{
[super viewDidLoad];
CGRect rect = CGRectMake(0.0f, 20.0f, 320.0f, 216.0f);
UIPickerView *myPickerView = [[UIPickerView alloc] initWithFrame:rect];
[self.view addSubview:myPickerView];
[myPickerView release];
}
您忘記了將UIPickerView的委託設置爲當前視圖。添加：
myPickerView.delegate = self;
...在您的初始化之後，在您的視圖之前。當然，確保您將頭文件設置爲UIPickerView委託並實現dataSource方法。
不是將uipickerview設置爲視圖控制器視圖的最好方法 – Max