Question

我创建了一个自定义UIView来保存一个选择器视图和一个带有几个按钮的导航栏。我还使用导航栏，2个按钮和选择器创建了一个自定义笔尖，所有这些都链接到我的头文件。我让它成为每个单独的类的委托，以处理所有的选择器视图委托。我的问题是它在需要时不会在屏幕上显示。我知道该方法被调用但自定义视图不会出现。以下是我的代码。

CustomPicker.m：

- (IBAction)selectClick:(id)sender
{
    NSObject *obj = [self.list objectAtIndex:[self.picker selectedRowInComponent:0]];
    [self.delegate pickerDidSelect:obj];
}

- (IBAction)selectCancel:(id)sender
{
    [self.delegate removePickerFromView:self];
}

- (id)initWithFrame:(CGRect)frame
{
    frame.size = CGSizeMake(320, 260);
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }

    self.picker = [[UIPickerView alloc] init];
    self.picker.dataSource = self;
    self.picker.delegate = self;
    self.picker.showsSelectionIndicator = YES;

    return self;
}

-(NSInteger) numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    return [self.delegate numberOfComponentsInPicker:pickerView];
}

-(NSInteger) pickerView: (UIPickerView *) pickerView numberOfRowsInComponent:(NSInteger)component
{
    return [self.delegate picker:pickerView numberOfRowsInComponent:component];
}

-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    return [self.delegate picker:pickerView titleForRow:row forComponent:component];
}

要求显示的方法

-(void)displayPicker
{
    NSLog(@"display picker");
    picker = [[CustomPicker alloc] initWithFrame:CGRectMake(0, self.view.frame.size.height, 320, 260)];
#warning picker set up incomplete
    [self.view addSubview:picker];
    CGRect frame = picker.frame;
    frame.origin = CGPointMake(0, self.view.frame.size.height - 260);
    [UIView animateWithDuration:1.5 animations:^{
        [picker setFrame:frame];
    }];
}

现在，我只是不明白为什么我的自定义视图没有显示。

谢谢！

Answer 1

CustomPicker类的实现不会向自身添加任何子视图。您的自定义选择器视图已正确添加并显示，但它是空的，因此无需查看。

更新initWithFrame: CustomPicker方法，将self.picker添加到self。

[self addSubview:self.picker];

顺便说一句 - 您创建和设置UIPickerView的代码应该在if语句中完成。如果self为nil，则您不想运行该代码。

- (id)initWithFrame:(CGRect)frame
{
    frame.size = CGSizeMake(320, 260);
    self = [super initWithFrame:frame];
    if (self) {
        self.picker = [[UIPickerView alloc] init];
        self.picker.dataSource = self;
        self.picker.delegate = self;
        self.picker.showsSelectionIndicator = YES;
        [self addSubview:self.picker];
    }

    return self;
}

我的自定义UIView没有显示在屏幕上

1 个答案: