NSTextField控件一些用法

对于大部分iOS开发者而言UITextField并不陌生,然而maccocoa开发接触的更底层的cocoa框架,相对于iOS框架更加完善和可扩展性更高,但相对来说增加了难度.今天就大致讲一下NSTextField一些常见的使用技巧.

分别为:NSTextField和NSSecureTextField

1. NSTextField和NSSecureTextField的自定义

@property (nullable, copy) NSString *placeholderString NS_AVAILABLE_MAC(10_10);
@property (nullable, copy) NSAttributedString *placeholderAttributedString NS_AVAILABLE_MAC(10_10);

@property (nullable, copy) NSColor *backgroundColor;
@property BOOL drawsBackground;
@property (nullable, copy) NSColor *textColor;
@property (getter=isBordered) BOOL bordered;
@property (getter=isBezeled) BOOL bezeled;
@property (getter=isEditable) BOOL editable;
@property (getter=isSelectable) BOOL selectable;
- (void)selectText:(nullable id)sender;
@property (nullable, weak) id<NSTextFieldDelegate> delegate;
- (BOOL)textShouldBeginEditing:(NSText *)textObject;
- (BOOL)textShouldEndEditing:(NSText *)textObject;
- (void)textDidBeginEditing:(NSNotification *)notification;
- (void)textDidEndEditing:(NSNotification *)notification;
- (void)textDidChange:(NSNotification *)notification;
@property (readonly) BOOL acceptsFirstResponder;
@property NSTextFieldBezelStyle bezelStyle;

上面API写的很清楚,如果不理解的可以下面回复询问.
主要是利用上面的属性做到一些自定义控件.如下:

- (instancetype)init {
    self = [super init];
    if (self) {
        self.bezelStyle = NSTextFieldRoundedBezel;
        self.bordered = NO;
        self.focusRingType = NSFocusRingTypeNone;
        self.font = [NSFont systemFontOfSize:15.0f];
        self.delegate =self;
    }
    return self;
}
// 为文本增加下划线
- (void)drawRect:(NSRect)dirtyRect {
    [super drawRect:dirtyRect];
    
    NSRect rect = CGRectMake(0, dirtyRect.size.height-10, dirtyRect.size.width, 1);
    NSBezierPath *path = [NSBezierPath bezierPathWithRect:rect];
    [EC_RGB_String(@"#d9dcde") set];
    [path fill];
}
// 占位文本的清除
- (BOOL)becomeFirstResponder {
    if (self.placeholderString.length>0 && EC_MAC_OS_X_10_10) {
        self.placeStr = self.placeholderString;
        self.placeholderString = @"";
    }
    return [super becomeFirstResponder];
}
// 以下可以自定义编写一些定时化的需求. NSNotification的对象是NSTextView.
- (BOOL)textShouldBeginEditing:(NSText *)textObject;
- (BOOL)textShouldEndEditing:(NSText *)textObject;
- (void)textDidBeginEditing:(NSNotification *)notification;
- (void)textDidEndEditing:(NSNotification *)notification;
- (void)textDidChange:(NSNotification *)notification;

2. NSTextField和NSSecureTextField接收键盘控制以及控制文本的长度.

// 尽量让controller作为TextField的代理.
#pragma mark - NSTextFieldDelegate
-(BOOL)control:(NSControl *)control textView:(NSTextView *)textView doCommandBySelector:(SEL)commandSelector {
    if (commandSelector == @selector(insertNewline:)) {// 监听键盘的回车事件.
        [self loginWithAccount:_accountF.stringValue pwd:_pwdF.stringValue];
        return true;
    }
    return false;
}
// 控制文本输入框的内容长度.
-(void)controlTextDidChange:(NSNotification *)obj {
    NSInteger accountMaxLimit = 18;
    if (self.accountF.stringValue.length > accountMaxLimit && obj.object == self.accountF)
        self.accountF.stringValue = [self.accountF.stringValue substringToIndex:accountMaxLimit];
    if (self.pwdF.stringValue.length > accountMaxLimit && obj.object == self.pwdF)
        self.pwdF.stringValue = [self.pwdF.stringValue substringToIndex:accountMaxLimit];
}

3. 文本框默认选中状态.

类似mac电脑上qq客户端登陆页面账号文本框是选中状态,方便用户回车登录.

// 设置以下属性值可以让文本框默认选中状态.
- (void)viewDidAppear {
    [super viewDidAppear];
    [self.accountF setSelectable:YES];
    [self.accountF selectText:self];
}

特别提醒

NSSecureTextField控件控制输入内容是暗文的控件.