objective-c - UITableView 滚动后 UITextFields 重叠

Question

我有一个带有 UITextFields 的 UITableView 来制作表单。它看起来很棒 - 除非当你滚动时，新的 UITextFields 被放置在旧的 UITextFields 之上......我不明白为什么!我知道当单元格被重用时(即 dequeueReusableCellWithIdentifier 返回非零)，单元格将与现有的 UITextField 一起返回。我找到了一个解决方案，可以保持标签的唯一性，最好删除任何以前的 UITextField。但我不想那样做。最后提交此表单时，我想从文本字段中获取所有值(如果删除它们则无法做到这一点)..

这是代码。如有任何帮助，我们将不胜感激!

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = (UITableViewCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

if (cell == nil)
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];

cell.accessoryType = UITableViewCellAccessoryNone;

UITextField *playerTextField = [[UITextField alloc] initWithFrame:CGRectMake(155, 15, 130, 30)];
playerTextField.adjustsFontSizeToFitWidth = YES;
playerTextField.textColor = [UIColor blackColor];

if (indexPath.row == 0) {
    playerTextField.placeholder = @"Unique ID Sample";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyNext;
}

else if (indexPath.row == 1) {
    playerTextField.placeholder = @"Common Name";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if (indexPath.row == 2) {
    playerTextField.placeholder = @"Scientific Name";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 3) {
    playerTextField.placeholder = @"03/25/1992";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 4) {
    playerTextField.placeholder = @"Male";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
} 

else if ([indexPath row] == 5) {
    playerTextField.placeholder = @"03/01/2012";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 6) {
    playerTextField.placeholder = @"Huntington, WV";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 7) {
    playerTextField.placeholder = @"Huntington, WV";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 8) {
    playerTextField.placeholder = @"Marshall University";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
} 
else if ([indexPath row] == 9) {
    playerTextField.placeholder = @"Sub Straight";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 10) {
    playerTextField.placeholder = @"Any Light";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 11) {
    playerTextField.placeholder = @"Temperature";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 12) {
    playerTextField.placeholder = @"A Lot";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
} 

else if ([indexPath row] == 13) {
    playerTextField.placeholder = @"All Types";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 14) {
    playerTextField.placeholder = @"Schedule";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 15) {
    playerTextField.placeholder = @"MM/DD/YYYY";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 16) {
    playerTextField.placeholder = @"Ate Someone";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
} 

else if ([indexPath row] == 17) {
    playerTextField.placeholder = @"MM/DD/YYYY";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 18) {
    playerTextField.placeholder = @"The Morgue";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 19) {
    playerTextField.placeholder = @"MM/DD/YYYY";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}

else if ([indexPath row] == 20) {
    playerTextField.placeholder = @"MM/DD/YYYY";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
} 

else if ([indexPath row] == 21) {
    playerTextField.placeholder = @"To/ From";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyDone;
}    

playerTextField.backgroundColor = [UIColor whiteColor];
playerTextField.autocorrectionType = UITextAutocorrectionTypeNo; // no auto correction support
playerTextField.autocapitalizationType = UITextAutocapitalizationTypeNone; // no auto capitalization support
playerTextField.textAlignment = UITextAlignmentLeft;
playerTextField.tag = 0;

playerTextField.clearButtonMode = UITextFieldViewModeNever; // no clear 'x' button to the right
[playerTextField setEnabled: YES];

    [cell addSubview:playerTextField];

[playerTextField release];

cell.textLabel.text = [self.options objectAtIndex:indexPath.row];


return cell;    
}

Answer 1

您必须创建一个自定义UITableViewCell。这将允许您创建一个带有可直接访问的 UITextField 的 ivar。这样，当单元出队并重新使用时，您只需在需要时进行设置即可。请务必在单元子类中重写 prepareForReuse: 并重置添加的组件上的所有属性。

另一件事可以帮助您解决上面的代码，那就是使用 typedef enum 而不是使用整数来确定单元格的类型:

typedef enum{
    PlayerFieldId = 0,
    PlayerFieldName,
    PlayerFieldGender
} PlayerFields

然后在任一自定义单元格中，您可以通过上面的枚举和 switch 语句设置单元格类型:

switch(type){
case PlayerFieldId:
    playerTextField.placeholder = @"Unique ID Sample";
    playerTextField.keyboardType = UIKeyboardTypeDefault;
    playerTextField.returnKeyType = UIReturnKeyNext;
    break;
    /* other fields here */
}