如何将UIPickerView重置为索引:0,iPhone

Question

我正在尝试重置UIPickerView点击按钮.我的pickerview id是在运行时创建的,我已经设置了委托.谷歌搜索后,我找到了

[pickerView reloadAllComponents];

但这会让我的应用程序每次到达时都会崩溃.

索引0处的对象是"从列表中选择",然后是项目.单击提交按钮时,我希望"从列表中选择"应保留在我的标签顶部(选定索引:0).

这是我的代码

ViewDidload

 pickerView = [[UIPickerView alloc] init];
    pickerView.delegate = self;
    pickerView.dataSource = self;

  -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
        return 1;
    }


 // Total rows in our component.
    -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
        return [nameArray count];
    }

// Display each row's data.
-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{
    return [nameArray objectAtIndex: row];
    }

// Do something with the selected row.

    -(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{
        dlbl.hidden=YES;
        NSLog(@"You selected this: %@", [nameArray objectAtIndex: row]);
        [btnSelectDesigner setTitle:[nameArray objectAtIndex: row] forState:UIControlStateNormal]; 

    }

并在按钮上单击:

-(IBAction)btnSubmitClicked:(id)sender{
[pickerView reloadAllComponents];
}

知道我做错了什么吗？

谢谢

Answer 1

[picker reloadAllComponents];
[picker selectRow:0 inComponent:0 animated:YES];

Answer 2

Swift版本:

picker.selectRow(0, inComponent: 0, animated: true)

Answer 3

//use this line for going at the top of the label index 0:

[picker selectRow:0 inComponent:0 animated:YES];