如何从具有2个组件的UIPickerView获取选定的值

Question

我在这里有一个问题，我问如何从UIPickerView获取值 （ 如何从UIPickerView获取选定的值 ）。 我有一个组件为1的选择器的解决方案，但现在我想从组件为2的选择器中获取值。

此代码适用于具有1个组件的选择器：

    NSInteger row;
    NSString *weightSelected;

    row = [repPicker selectedRowInComponent:0];
    weightSelected = [pickerArray objectAtIndex:row];

我为带有2个组件的选择器厌倦了这段代码，但是它冻结了。 控制台中也没有错误。 它冻结的行是row2 = [repPicker selectedRowInComponent:1]; ：

    NSInteger row1, row2;
    NSString *weightSelected1;
    NSString *weightSelected2;

    row1 = [repPicker selectedRowInComponent:0];
    row2 = [repPicker selectedRowInComponent:1];
    weightSelected1 = [pickerArray objectAtIndex:row1];
    weightSelected2 = [pickerArray objectAtIndex:row2];
    NSString *weightSelected = [NSString stringWithFormat:@"%@.%@", weightSelected1, weightSelected2];

更新：

#pragma mark - Weight Picker 
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)thePickerView 
{
    if (thePickerView.tag==1)
    {
    return 2;
    }
    else
        return 1;
}

- (NSInteger)pickerView:(UIPickerView *)thePickerView numberOfRowsInComponent:(NSInteger)component 
{
    if (thePickerView.tag==1)
    {
        if (component == 0)
            return [pickerArray count];
        if (component == 1)
            return [pickerArrayHalf count];
    }
    else
        return [pickerArray count];
}

- (void)pickerView:(UIPickerView *)thePickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component 
{

   // NSLog(@"Selected Color: %@. Index of selected color: %i", [weightArray objectAtIndex:row], row);
}

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
    if (pickerView.tag==1)
    {
        if (component == 0)
        {
            UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 300, 37)];
            int weight = [[pickerArray objectAtIndex:row] intValue];
            label.text = [NSString stringWithFormat:@"%d", weight];

            label.textAlignment = UITextAlignmentCenter;
            label.backgroundColor = [UIColor clearColor];
            label.font = [UIFont boldSystemFontOfSize:30];
            [label autorelease];
            return label;
        }

        else
        {
            UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 300, 37)];
            label.text = [pickerArrayHalf objectAtIndex:row];
            label.textAlignment = UITextAlignmentCenter;
            label.backgroundColor = [UIColor clearColor];
            label.font = [UIFont boldSystemFontOfSize:30];
            [label autorelease];
            return label;
        }
    }

    else
    {
        int reps = [[pickerArray objectAtIndex:row] intValue];
        UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 300, 37)];
        label.text = [NSString stringWithFormat:@"%d reps", reps];
        label.textAlignment = UITextAlignmentCenter;
        label.backgroundColor = [UIColor clearColor];
        label.font = [UIFont boldSystemFontOfSize:30];
        [label autorelease];
        return label;
    }
}

再次更新：

我添加了以下代码：

- (void)pickerView:(UIPickerView *)thePickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component 
{

    NSLog(@"Selected Color: %@. Index of selected row: %i", [pickerArray objectAtIndex:row], row);
    NSLog(@"Component 0: %@", [repPicker selectedRowInComponent:0]);
    NSLog(@"Component 1: %@", [repPicker selectedRowInComponent:1]);
}

现在，我现在在以下位置滚动单击器时会崩溃：NSLog（@“ Component 1：％@”，[repPicker selectedRowInComponent：1]）;

错误：

*由于未捕获的异常'NSRangeException'而终止应用程序，原因：'* -[NSMutableArray objectAtIndex：]：索引1超出范围[0 .. 0]'

我也有Component 0: (null)

更新：

声明pickerArray的代码：

pickerArray = [[NSMutableArray alloc] initWithCapacity:700];
    for ( int i = 0 ; i <= 1000 ; ++i)
        [pickerArray addObject:[NSString stringWithFormat:@"%d", i]];

    pickerArrayHalf = [[NSMutableArray alloc]initWithCapacity:2];
    [pickerArrayHalf addObject:@"0 lb"];
    [pickerArrayHalf addObject:@"1/2 lb"];

Answer 1

冷冻？ 穿一件毛衣:-)其实，日志上写着什么-您知道它在哪里冻结吗？ 放置NSLog语句以查找确切的行，或通过调试器逐步执行。

Answer 2

也许是NSLog(@"repPicker: %@", repPicker); 可以帮助弄清楚那里发生了什么。

编辑：您正在初始化具有容量700的pickerArray并添加1000个对象。 这是行不通的。 我会用pickerArray = [[NSMutableArray] alloc] init]; 并添加1000个对象。