[Cocoa]_[初级]_[NSPopUpButton重绘实例]

场景：比如说，定义一个支持多种格式的控件，包含下拉菜单进行多种选择.由于标准的控件在界面上布局和自己所需的相差很多，所以要对控件进行重绘。

一下是具体实例：

类似于带下拉菜单的文本编辑框。

//
//  MqjPopUpButton.m
//  MqjEditContact
//
//  Created by mac-d on 4/28/15.
//  Copyright (c) 2015 mac-d. All rights reserved.
//

#import "MqjPopUpButton.h"

@implementation MqjPopUpButton


- (id)initWithFrame:(NSRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code here.
    }
    
    return self;
}
-(BOOL) isFlipped
{
    return YES;
}

- (void)drawRect:(NSRect)dirtyRect
{
    // Drawing code here.
    //[super drawRect:dirtyRect];
    [[NSColor colorWithCalibratedRed: 255/255.0 green:255/255.0 blue:255/255.0 alpha:1] setFill];
    NSRectFill(dirtyRect);
    
    
    
    NSString *path =[[NSBundle mainBundle] pathForResource:@"down" ofType:@"png"];
    NSImage *image =[[NSImage alloc] initWithContentsOfFile:path];
    NSRect rect =NSZeroRect;
    rect.size = [image size];
    NSPoint p = dirtyRect.origin;
    p.x +=dirtyRect.size.width-image.size.width-4;
    p.y +=(dirtyRect.size.height-image.size.height)/2;
    [image drawInRect:NSMakeRect(p.x, p.y, image.size.width, image.size.height) fromRect:rect operation:NSCompositeSourceOver fraction:1.0 respectFlipped:YES hints:nil];
    
    //画横线
    NSBezierPath *line = [NSBezierPath bezierPath];
    [line setLineWidth:1];
    [[NSColor colorWithCalibratedRed: 147/255.0 green:147/255.0 blue:147/255.0 alpha:0.5] setStroke];
    
    NSPoint endPoint = dirtyRect.origin;
    endPoint.x += dirtyRect.size.width;
    [line moveToPoint:dirtyRect.origin];
    [line lineToPoint:endPoint];
    [line stroke];
    
    [line moveToPoint:NSMakePoint(dirtyRect.origin.x, dirtyRect.origin.y+dirtyRect.size.height)];
    [line lineToPoint:NSMakePoint(endPoint.x,dirtyRect.origin.y+dirtyRect.size.height)];
    [line stroke];
    
    //画竖线
    [line moveToPoint:dirtyRect.origin];
    [line lineToPoint:NSMakePoint(dirtyRect.origin.x,dirtyRect.origin.y+dirtyRect.size.height)];
    [line stroke];
    
    [line moveToPoint:endPoint];
    [line lineToPoint:NSMakePoint(endPoint.x,dirtyRect.origin.y+dirtyRect.size.height)];
    [line stroke];
    
    //对选中的item设置勾选
    NSArray *array = [super itemArray];
    for(NSMenuItem *item in array)
    {
        if (item == [self selectedItem])
        {
            [item setState:NSOnState];
        }
        else
        {
            [item setState:NSOffState];
        }
        
    }
     
    NSString *title =[[super selectedItem] title];
    if (title == nil)
    {
        title = @"";
    }
    NSLog(@"title:%@",title);
    
    //获取字符串的宽度和高度
    NSSize titleSize = [title sizeWithAttributes:[NSDictionary dictionaryWithObject:[self font] forKey:NSFontAttributeName]];
    CGFloat titleY = dirtyRect.origin.y + (dirtyRect.size.height - titleSize.height)/2;
    
    NSRect rectTitle = dirtyRect;
    
    rectTitle.origin = NSMakePoint(10, titleY);
    
    rectTitle.size.height = titleSize.height;
    
    [title drawInRect:rectTitle withAttributes:nil];
}

@end

在MainMenu.xib布局一个NSPopUpButton,class:改为如图所示。

运行结果：