因为网上没有查到相关方法，故而采用一种假象的方法来实现，选项循环滚动
- (void)viewDidLoad {
[super viewDidLoad];
/**
UIPickerView 选择器
*/
CGFloat Y = [UIScreen mainScreen].bounds.size.height-120;
CGFloat W = [UIScreen mainScreen].bounds.size.width;
CGFloat H = 120;
UIPickerView *pickerView = [[UIPickerView alloc]initWithFrame:CGRectMake(0, Y, W, H)];
pickerView.showsSelectionIndicator = YES;
pickerView.backgroundColor = [UIColor whiteColor];
pickerView.dataSource = self;
pickerView.delegate = self;
[self.view addSubview:pickerView];
//数据源
self.group = @[@[@"1",@"2",@"3"],@[@"11",@"22",@"33",@"44"],@[@"111",@"222",@"333"]];
//设定 默认选中的 一行（比如：1 2 3...6 7 8...10,默认选择在“5”上）
// [pickerView selectRow:5 inComponent:1 animated:YES];
for (int i = 0; i<self.group.count; i++) {
[pickerView selectRow:150 inComponent:i animated:YES];
}
}
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
return self.group.count;
}
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
NSArray *arr = self.group[component];
return arr.count * 100;
}
-(CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component{
return 50;
}
-(CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component{
return 50;
}
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
if (component == 1) {
return [self.group[component] objectAtIndex:row % 4];
}else{
return [self.group[component] objectAtIndex:row % 3];
}
}