我有一份个人资料表格，作为 iOS 应用程序注册过程的一部分。

我想为性别、职位、出生日期等项目使用“下拉”菜单。每个项目的数据都是静态的——我将使用 UIPickerView 来实现——但我的问题是——我需要吗创建数组和数据委托(delegate)来填充每个单独的选择器，或者是否有更简单的方法来应用静态数据？

最佳答案

你能在没有代表的情况下做到吗？没有。

你可以不用数组吗？是的，但你不应该。

这是一个没有数组的例子(来自 http://cocoamatic.blogspot.com/2010/08/create-uipickerview-programmatically.html )。

- (void)pickerView:(UIPickerView *)pickerView didSelectRow: (NSInteger)row inComponent:(NSInteger)component {
    // Handle the selection
}

// tell the picker how many rows are available for a given component
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
    NSUInteger numRows = 3;

    return numRows;
}

// tell the picker how many components it will have
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
 return 1;
}

// tell the picker the title for a given component
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
    NSString *title;

    title = [@"" stringByAppendingFormat:@"Row %d",row];

    return title;
}

// tell the picker the width of each row for a given component
- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component {
 int sectionWidth = 300;

 return sectionWidth;
}

但是，您真的应该只使用数组，这样可以更轻松地阅读和维护。如果你想添加一个额外的值，你只需将它添加到你的数组中。无需在多个位置进行更新，只需向数组添加另一个值即可。而且，更容易理解。

@implementation PickerViewController
.
.
- (void)viewDidLoad {
      [super viewDidLoad];
      _myArray = @[@"Row 1", @"Row 2", @"Row 3",];
}

- (void)pickerView:(UIPickerView *)pickerView didSelectRow: (NSInteger)row inComponent:(NSInteger)component {
    // Handle the selection
}

// tell the picker how many rows are available for a given component
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
    NSUInteger numRows = 3;

    return _myArray.count;
}

// tell the picker how many components it will have
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
 return 1;
}

// tell the picker the title for a given component
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
    NSString *title;

    title = myArray[row];

    return title;
}

// tell the picker the width of each row for a given component
- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component {
 int sectionWidth = 300;

 return sectionWidth;
}

如果您有多个选择器，您只需使用多个数组并检查每个 PickerView 以查看您拥有哪个，因为 PickerView 已传递到列出的每个函数中。

@implementation PickerViewController
.
.
- (void)viewDidLoad {
      [super viewDidLoad];
      _myArray1 = @[@"Row 1", @"Row 2", @"Row 3",];
      _myArray2 = @[@"Row 1-2", @"Row 2-2", @"Row 3-2", @"Row 4-2"];      

      UIPickerView pickerView1 = [[UIPickerView alloc] init];
      UIPickerView pickerView2 = [[UIPickerView alloc] init];      
}

- (void)pickerView:(UIPickerView *)pickerView didSelectRow: (NSInteger)row inComponent:(NSInteger)component {
    // Handle the selection
    if (pickerView == pickerView1)
    {
        // First Picker
    }
    else if (pickerView == pickerView2)
    {
        // First Picker    
    }
}

// tell the picker how many rows are available for a given component
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
    if (pickerView == pickerView1)
    {
        // First Picker
         return _myArray1.count;
    }
    else if (pickerView == pickerView2)
    {
        // Second Picker    
        return _myArray2.count;
    }    

    // A third picker passed in somehow
    return 0;
}

// tell the picker how many components it will have
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
    if (pickerView == pickerView1)
    {
        // First Picker
         return 1;
    }
    else if (pickerView == pickerView2)
    {
        // Second Picker    
        return 1;
    }    

    // A third picker passed in somehow
    return 0;
}

// tell the picker the title for a given component
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
    NSString *title;

    if (pickerView == pickerView1)
    {
        // First Picker
         title = myArray1[row];
    }
    else if (pickerView == pickerView2)
    {
        // Second Picker    
        rtitle = myArray2[row];
    }    

    return title;
}

// tell the picker the width of each row for a given component
- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component {
    if (pickerView == pickerView1)
    {
        // First Picker
         return 300;
    }
    else if (pickerView == pickerView2)
    {
        // Second Picker    
        return 400;
    }    

    // A third picker passed in somehow
    return 0;
}

关于iOS - 填充静态 UIPickerView，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/21191718/