解决简单的NSCSF数问题

Question

在第-[NSCFNumber length]: unrecognized selector sent to instance行获取错误：[firstComponentText setString:[pickerArray objectAtIndex:row]];。

-(void) viewDidLoad
pickerArray = [[NSMutableArray alloc] initWithCapacity:700];
    for ( float i = 0.0 ; i <= 1000.0 ; i = i + 2.5)
        [pickerArray addObject:[NSNumber numberWithFloat:i]];

- (void)pickerView:(UIPickerView *)thePickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component 
    {
        if (thePickerView.tag==1)//weight
        {
            [firstComponentText setString:[pickerArray objectAtIndex:row]];
            weightLabel.text = firstComponentText;
        }
        }

Answer 1

您的pickerArray是否包含NSNumber个对象？如果是这样，要获得NSString，您需要使用+[NSString stringWithFormat:]或-[NSNumber stringValue]等方法。

如果是这种情况，请尝试以下任一方法：

[firstComponentText setString:[[pickerArray objectAtIndex:row] stringValue]];

或

[firstComponentText setString:[NSString stringWithFormat:@"%@", [pickerArray objectAtIndex:row]]];