Question

我尝试按如下方式将UITextField子类化，以将自定义rightView实现为Clear按钮：

-(void) drawRect:(CGRect)rect
{

    [self.layer setBackgroundColor:[[UIColor colorWithRed:20.0/255.0 green:20.0/255.0 blue:20.0/255.0 alpha:1] CGColor]];
    [self.layer setCornerRadius:15.0];

    UIImage  *imgClear = [UIImage imageNamed:@"btnClear"];
    CGSize iSize = [imgClear size];

    UIButton *clearButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, iSize.width, iSize.height)];

    [clearButton setImage:imgClear forState:UIControlStateNormal];
    [clearButton addTarget:self action:@selector(clearText:) forControlEvents:UIControlEventTouchUpInside];

    [self setRightViewMode:UITextFieldViewModeWhileEditing];
    [self setRightView:clearButton];

    [clearButton release];
}

但问题是：当文本字段变为焦点时，“清除”按钮也变得可见，在我开始点击键盘后它消失了。有什么想法吗？

Answer 1

我也遇到了同样的问题。我想这是一个iOS错误，但是，我尝试通过以下实现解决这个问题，它对我来说很好。希望这会对你有所帮助。

- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString {
    ...
    [self addTarget:self action:@selector(onEditing:) forControlEvents: UIControlEventEditingChanged]
    ...
}

-(void) onEditing:(id)sender {
    if(![self.text isEqualToString:@""]){
        self.rightViewMode = UITextFieldViewModeAlways;
    }else{
        self.rightViewMode = UITextFieldViewModeNever;
    }
}
- (BOOL)becomeFirstResponder{
    BOOL ret = YES ;
    ret = [super becomeFirstResponder] ;
    if( ret & ![self.text isEqualToString:@""]){
        self.rightViewMode = UITextFieldViewModeAlways;
    }else{
        self.rightViewMode = UITextFieldViewModeNever;
    }

    return ret ;
}
- (BOOL)resignFirstResponder
{
    BOOL ret = YES ;
    ret = [super resignFirstResponder] ;
    if( ret )
        self.rightViewMode = UITextFieldViewModeNever;
    return ret ;
}
- (void) clearText:(id)sender
{
    self.text = @"";
    self.rightViewMode = UITextFieldViewModeNever;
}

Answer 2

您应该使用：[self setRightViewMode:UITextFieldViewModeAlways];

Answer 3

UITextField的子类和覆盖-layoutSubviews。

- (void)layoutSubviews
{
   [super layoutSubviews];

   // HACK: There is an iOS bug where the right view is not displayed when there is text in the text field. Also, iOS adds and removes the rightView. This code adds the right view and uses hide-unhide instead.

   UIView *rightView = [self rightView];

   if (rightView != nil && [self clearButtonMode] == UITextFieldViewModeNever) {
      BOOL showRightView;
      BOOL isFirstResponder = [self isFirstResponder];

      switch ([self rightViewMode]) {
      case UITextFieldViewModeNever:
         showRightView = FALSE;
         break;
      case UITextFieldViewModeWhileEditing:
         showRightView = isFirstResponder;
         break;
      case UITextFieldViewModeUnlessEditing:
         showRightView = !isFirstResponder;
         break;
      case UITextFieldViewModeAlways:
      default:
         showRightView = TRUE;
         break;         
      }

      showRightView = (showRightView && ![[self text] isEqualToString:@""]);

      [rightView setFrame:[self rightViewRectForBounds:[self bounds]]];
      [rightView setHidden:!showRightView];

      [self addSubview:rightView];
   }
}

Answer 4

- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString {
    UITextField *searchField = nil;
    for (UIView *subview in controller.searchBar.subviews) {
        DebugLog(@"%@",[subview description]);
        if ([subview isKindOfClass:[UITextField class]]) {
            searchField = (UITextField *)subview;
            UIImageView *clearIconView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"ClearIcon.png"]];
            searchField.rightView = clearIconView;
            searchField.rightViewMode = UITextFieldViewModeAlways;

            [clearIconView release];
            break;
        }
    }
}

Answer 5

解决此问题的简单代码

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    textField.rightViewMode=UITextFieldViewModeAlways;
}

- (BOOL)textFieldShouldEndEditing:(UITextField *)textField
{
     textField.rightViewMode=UITextFieldViewModeNever;
    return YES;
}

Answer 6

我编写了一个开源类STAResizingTextField，允许您指定自定义明文字段按钮图像。

UITextField rightView“WhileEditing”问题

6 个答案: