如何在uitableviewcontroller中动态添加单元格? [英] How to add cell dynamically in uitableviewcontroller?

问题描述

具有两个 textFields 的单元格...单击添加按钮，我想在 tableview 中动态添加该单元格.并删除行.在滚动和添加新单元格期间，两个 textField 上的文本不应更改...

cell which having two textFields... And on click ADD button I want to add that cell dynamically in tableview. And also delete row. And text on both textField should not get change during scroll and on adding new cell...

最后我想要字典数组中的所有文本字段值..

And at the end I want all text field value in array of Dictionary..

按照我试过的代码

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
     return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [itemsArray count];
}

-(void) setEditing:(BOOL)editing animated:(BOOL)animated {
    [super setEditing:editing animated:animated];
    [self.tableView setEditing:editing animated:animated];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    AddItemTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"addItemCellIdentifier"];
    if (cell == nil) {
        cell = [[AddItemTableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"addItemCellIdentifier"];
    }
    return cell;
}
-(BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
    return YES;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
    if (editingStyle == UITableViewCellEditingStyleDelete) {

       [itemsArray removeObjectAtIndex:indexPath.row];
        [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];

- (IBAction)addItemBtnClick:(id)sender {


    if ([itemsArray count]) {
        [itemsArray removeLastObject];
        NSIndexPath *index = [NSIndexPath indexPathForRow:0 inSection:0];
        AddItemTableViewCell *Cell = (AddItemTableViewCell *)[self.tableView cellForRowAtIndexPath:index];
        UITextField * name = (UITextField *)[Cell.contentView viewWithTag:11];
        UITextField * Qty = (UITextField *)[Cell.contentView viewWithTag:12];
        NSMutableDictionary *item = [NSMutableDictionary new];
        [item setObject:name.text forKey:@"item"];
        [item setObject:Qty.text forKey:@"quantity"];
        [itemsArray addObject:item];
    }
    [itemsArray addObject:@{@"item":@"",@"quantity":@""}];
    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
    [self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}

推荐答案

您的单元格将显示重复的文本字段值，因为您正在重用它们，并且在现在希望单元格代表不同对象时未调整单元格详细信息.

Your cell will show repeated textfield values because you are reusing them and not adjusting the cell details when a cell is now expected to represent a different object.

如果您不想要这种行为(您显然不想要)，那么您需要在数据源上设置单元格详细信息.然后在 cellForRowAtIndexPath() 中使用相应的对象详细信息填充当前单元格.或者，我不建议这样做，您可以在 cellForRowAtIndexPath() 中为添加的每个项目分配初始化一个新单元格.当您的单元格在屏幕上不可见时，这将不必要地消耗更多内存.

If you do not want this behaviour (you obviously don't) then you need to set the cell details on your dataSource. Then in cellForRowAtIndexPath() you populate the current cell with the respective object details. Or, which I do not advise, you can alloc init a new cell in cellForRowAtIndexPath() for each item you add. This will use up more memory unnecessarily when you have cells that are not visible on screen.

这里是一个例子:这只是为了演示从数据源动态填充单元格，其他一切都不是建议.

#import "PeopleTableViewController.h"

//--- Person Class
@interface Person : NSObject<UITextFieldDelegate>
@property (nonatomic, strong) NSString *name;
@property (nonatomic, strong) NSString *surname;
@end
@implementation Person
@end
//---

#define CELL_HEIGHT 80.0f
#define TEXTFIELD_HEIGHT 30.0f
#define TEXTFIELD_WIDTH 120.0f
#define TEXT_FIELD_VERTICAL_MARGIN (CELL_HEIGHT - (TEXTFIELD_HEIGHT*2)) / 3
#define TEXT_FIELD_LEFT_MARGIN 20.0f
//--- Person Cell
@class PersonCell;
@protocol  PersonCellTextFieldProtocol <NSObject>
-(void)personCell: (PersonCell*)cell nameTextfieldDidChange: (NSString*)newText;
-(void)personCell: (PersonCell*)cell surnameTextfieldDidChange: (NSString*)newText;
@end
@interface PersonCell : UITableViewCell<UITextFieldDelegate>
@property (nonatomic, strong) UITextField *nameTextField;
@property (nonatomic, strong) UITextField *surnameTextField;
@property (nonatomic, strong) UILabel *positionLabel;
@property (nonatomic, assign) id<PersonCellTextFieldProtocol> delegate;
@end
@implementation PersonCell
-(instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
    self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
    if(self)
        [self setupSubviews];
    return self;
}
-(void)setupSubviews
{
    NSUInteger nameTextFieldYPosition = TEXT_FIELD_VERTICAL_MARGIN;

    self.nameTextField = [[UITextField alloc] initWithFrame: CGRectMake(TEXT_FIELD_LEFT_MARGIN, nameTextFieldYPosition, TEXTFIELD_WIDTH, TEXTFIELD_HEIGHT)];
    self.nameTextField.borderStyle = UITextBorderStyleRoundedRect;
    self.nameTextField.placeholder = @"Name";
    self.nameTextField.delegate = self;
    [self.nameTextField addTarget:self action:@selector(nameTextFieldDidChange:) forControlEvents:UIControlEventEditingChanged];
    [self.contentView addSubview: self.nameTextField];

    self.surnameTextField = [[UITextField alloc] initWithFrame: CGRectMake(TEXT_FIELD_LEFT_MARGIN, CGRectGetMaxY(self.nameTextField.frame) + TEXT_FIELD_VERTICAL_MARGIN, TEXTFIELD_WIDTH, TEXTFIELD_HEIGHT)];
    self.surnameTextField.borderStyle = UITextBorderStyleRoundedRect;
    self.surnameTextField.placeholder = @"Surname";
    self.surnameTextField.delegate = self;
    [self.surnameTextField addTarget:self action:@selector(surnameTextFieldDidChange:) forControlEvents:UIControlEventEditingChanged];
    [self.contentView addSubview: self.surnameTextField];

    self.positionLabel = [[UILabel alloc] initWithFrame: CGRectMake(5, 0, 10, 20)];
    self.positionLabel.font = [UIFont systemFontOfSize: 10];
    [self.contentView addSubview: self.positionLabel];
    self.positionLabel.center = CGPointMake(self.positionLabel.center.x, self.contentView.center.y);
}

-(void)layoutSubviews
{
    self.positionLabel.center = CGPointMake(self.positionLabel.center.x, self.contentView.center.y);
}

-(void)nameTextFieldDidChange:(UITextField*)textField
{
    if([self.delegate respondsToSelector: @selector(personCell:nameTextfieldDidChange:)])
        [self.delegate personCell:self nameTextfieldDidChange:textField.text];
}

-(void)surnameTextFieldDidChange:(UITextField*)textField
{
    if([self.delegate respondsToSelector: @selector(personCell:surnameTextfieldDidChange:)])
        [self.delegate personCell:self surnameTextfieldDidChange:textField.text];
}

-(BOOL)textFieldShouldReturn:(UITextField *)textField
{
    [textField resignFirstResponder];
    return YES;
}
@end
//---

@interface PeopleTableViewController ()<PersonCellTextFieldProtocol>
@end

@implementation PeopleTableViewController
{
    NSMutableArray *_peopleArray;
}

-(void)viewDidLoad
{
    _peopleArray = [[NSMutableArray alloc] init];
    [self.tableView reloadData];
}

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    PersonCell *cell = nil;
    cell = [tableView dequeueReusableCellWithIdentifier: @"CellWithNameAndSurname"];
    if(!cell)
    {
        cell = [[PersonCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"CellWithNameAndSurname"];
        cell.contentView.backgroundColor = [[UIColor blueColor] colorWithAlphaComponent: 0.08f];
        cell.delegate = self;
    }

    //this should be outside the above if statement!
    Person *respectivePerson = _peopleArray[indexPath.row];
    cell.nameTextField.text = respectivePerson.name;
    cell.surnameTextField.text = respectivePerson.surname;
    cell.positionLabel.text = [NSString stringWithFormat:@"%i", (int)indexPath.row];

    return cell;
}

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return CELL_HEIGHT;
}

-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;
}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return _peopleArray.count;
}

-(void)personCell:(PersonCell *)cell nameTextfieldDidChange:(NSString *)newText
{
    Person *respectivePerson = _peopleArray[[self.tableView indexPathForCell: cell].row];
    respectivePerson.name = newText;
}

-(void)personCell:(PersonCell *)cell surnameTextfieldDidChange:(NSString *)newText
{
    Person *respectivePerson = _peopleArray[[self.tableView indexPathForCell: cell].row];
    respectivePerson.surname = newText;
}

- (IBAction)addItemBtnClick:(id)sender
{
    Person *newPerson = [Person new];

    [_peopleArray addObject: newPerson];

    [self.tableView reloadData];
}

@end

当我点击添加时，滚动时我得到下表，没有任何重复:

When I click add, I get the following table without any repetitions when I scroll:

这篇关于如何在uitableviewcontroller中动态添加单元格?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！