Question

我已经制作了4个pickerviews，每个有15个对象，我实现了所有委托方法。在组件数量上返回1，行数也是正确的，但是对于行方法行总是0并且pickerview没有显示。帮助我找到错误的地方。这是我的代码

-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
     NSLog(@"In Number Of Components Method\n");
     int numberOfComponents = 1;
     return numberOfComponents; 
}


-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent(NSInteger)component {
    NSMutableArray* keysArray = [[NSMutableArray alloc] init];
    NSMutableArray* valuesArray = [[NSMutableArray alloc]init];

    DBManager* dbManger = [[DBManager alloc] init];
    //companyName,city,category,postalCode
    NSInteger count = 0;
    switch (pickerView.tag) {
        case 0:
            if (![selectBusinessTextField.text isEqualToString:@""]) {
                [keysArray addObject:@"category"];
                [valuesArray addObject:selectBusinessTextField.text];
            }
            if (![selectCityTextField.text isEqualToString:@""]) {
                [keysArray addObject:@"city"];
                [valuesArray addObject:selectCityTextField.text];
            }
            if (![selectPostalCodeTextField.text isEqualToString:@""]) {
                [keysArray addObject:@"postalCode"];
                [valuesArray addObject:selectPostalCodeTextField.text];
            }

            if (keysArray.count) {
                alternateArrayFoBusinessNamesArray = [dbManger fetchColumn:@"companyName" whereKeysAre:keysArray andValuesAre:valuesArray];
            else
                alternateArrayFoBusinessNamesArray = [dbManger fetchColumn:@"companyName"];
            }

            count = alternateArrayFoBusinessNamesArray.count;
            break;
    } 
    return count;
}

-(UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view {

    UILabel* pickerItemLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, textFieldWidth, 40)];
    [pickerItemLabel setFont:[UIFont fontWithName:appFontBold size:18]];
    [pickerItemLabel setTextAlignment:NSTextAlignmentCenter];
    switch (pickerView.tag) {
        case 0:
        {
            NSString* name = [alternateArrayFoBusinessNamesArray objectAtIndex:row];
            [pickerItemLabel setText:[alternateArrayFoBusinessNamesArray objectAtIndex:row]];
        }
        break;
        case 1:
            [pickerItemLabel setText:[citiesNamesArray objectAtIndex:row]];
            break;
        case 2:
            if ([[businessTypesArray objectAtIndex:0]isKindOfClass:[NSDictionary class]])
                [pickerItemLabel setText:[businessTypesArray objectAtIndex:row]];
            else
                [pickerItemLabel setText:[businessTypesArray objectAtIndex:row]];
        break;
        case 3:
            [pickerItemLabel setText:[postalCodesArray objectAtIndex:row]];
        break;
    }
    return pickerItemLabel;
}

Answer 1

我发现问题是什么，除了pickerview的大小之外，每件事情都很好。我设置为0，就像在较旧的ios版本（＆lt; 9.0）中，pickerview高度被固定为0并且默认为216，现在它是可调整的，因此给出0意味着0而不是216.

iOS 9 Release Notes

＆＃34; UIPickerView和UIDatePicker现在可以调整大小自适应先前，即使这些视图也强制执行默认大小你试图调整它们的大小。这些视图现在也默认为宽度所有设备上的320点，而不是设备宽度 iPhone＆＃34;

因此，我将其更改为某种尺寸，并且每件事情都正常工作

uipickerview不显示行数> 0的数据

1 个答案: