Question

我正在尝试实现一个自定义NSTextField a）在激活时改变颜色，b）在左上角有一个标签。

我有以下实现：

在TestTextField.h

@interface TestTextField : NSTextField

- (id)initFullWidthWithLabel:(NSString *)label andPreset:(NSString *)preset;
...
@end

在TestTextField.m

@interface TestTextField() {

    BOOL _thisFieldIsActive;
}

@property (nonatomic, strong) NSTextField *label;

@end

@implementation TestTextField

- (id)initFullWidthWithLabel:(NSString *)label andPreset:(NSString *)preset {

    self = [super initWithFrame:NSZeroRect];
    if (self) {

        _thisFieldIsActive = NO;

        [self setFocusRingType:NSFocusRingTypeNone];

        // small label top left
        _label = [[NSTextField alloc] initWithFrame:NSZeroRect];
        _label.stringValue = label;

        if (preset) {
            self.stringValue = preset;
        }
        else {
            self.stringValue = @"0";
        }

        [self layoutUI];

    }
    return self;

}
- (void)turnActiveOff {
    [self toggleActive:NO];
}

- (void)toggleActive:(BOOL)active {

    _thisFieldIsActive = active;

    if (_thisFieldIsActive) {
        self.backgroundColor = [NSColor blueColor];
        self.textColor = [NSColor whiteColor];
        _label.textColor = [NSColor whiteColor];
    }
    else {
        self.backgroundColor = [NSColor clearColor];
        self.textColor = [NSColor blackColor];
        _label.textColor = [NSColor grayColor];
    }

}
- (BOOL)becomeFirstResponder {

    NSLog(@"BecomeFirstResponder");

    [self selectText:self];
    [self toggleActive:YES];

    return [super becomeFirstResponder];
}

- (void)textDidEndEditing:(NSNotification *)notification {
    NSLog(@"DidEndEditing");

    [self toggleActive:NO];
    [super textDidEndEditing:notification];
}

- (void)layoutUI {

    self.alignment = NSRightTextAlignment;
    self.font = [NSFont fontWithName:@"HelveticaNeue-Light" size:32.0f];
    self.layer.borderColor = [NSColor whiteColor].CGColor;
    self.layer.borderWidth = 1.0f;
    [self.layer setCornerRadius:4.0f];

    // small label top left
    _label.font = [NSFont fontWithName:@"HelveticaNeue-Light" size:12.0f];
    _label.alignment = NSLeftTextAlignment;
    _label.textColor = [NSColor grayColor];
    _label.stringValue = [_label.stringValue uppercaseString];
    _label.selectable = NO;
    _label.editable = NO;
    _label.drawsBackground = NO;
    _label.bezeled = NO;
    [self addSubview:_label];

    NSDictionary *metrics = @{@"borderPadding": @5};

    _label.translatesAutoresizingMaskIntoConstraints = NO;
    [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-(borderPadding)-[_label(100)]" options:0 metrics:metrics views:@{ @"_label" : _label }]];
    [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-(borderPadding)-[_label(30)]" options:0 metrics:metrics views:@{ @"_label" : _label }]];

}

在我的ViewController中，我只需调用自定义initFullWidthWithLabel:andPreset:方法并将其作为子视图添加到VC view

来实现这些TestTextFields

我可以看到标签定位正确，但是一旦字段变为活动状态并且设置了backgroundColor，它似乎就会掩盖标签。如何确保标签保持在最顶层？即使关闭了backgorund着色，标签仍然是隐藏的。

由于

Answer 1

解决方案的核心是使用自定义子类NSTextFieldCell和一种方法：

- (NSRect)drawingRectForBounds:(NSRect)rect {
    NSRect rectInset = NSMakeRect(rect.origin.x + 100.0f, rect.origin.y, rect.size.width - 100.0f, rect.size.height);
    return [super drawingRectForBounds:rectInset];
}

将不可编辑的NSTextField作为标签添加到另一个NSTextField中

1 个答案: