IOS 6 自定义 UIView by paintcode

Question

我是IOS新手。

我正在尝试使用 paintcode 生成的代码显示自定义按钮。我在 Storyboard 上拖动一个 View ，然后将这个通用 View 类设置为我的自定义 View “GreenButton”。当我运行该应用程序时，该按钮不显示。我添加了 NSLogs，可以看到 drawRect 方法成功运行。

paintcode 生成的代码似乎包含了绘制按钮的所有内容。我只是使用 XCode 调整 View 大小。

我是否需要实现 initWithFrame 方法？

//
//  GreenButton.m
//  Test
//
//  Created by Tim on 13.04.2013.
//  Copyright (c) 2013 Tim. All rights reserved.
//

#import "GreenButton.h"

@implementation GreenButton

- (id)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        // setup the initial properties of the view

    }
    return self;

}

#pragma mark - Touch event overrides


// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    NSLog(@"drawRect enter");
    //// General Declarations
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = UIGraphicsGetCurrentContext();

    //// Color Declarations
    UIColor* strokeColor = [UIColor colorWithRed: 0.419 green: 0.434 blue: 0.455 alpha: 1];
    UIColor* baseColor = [UIColor colorWithRed: 0.218 green: 0.24 blue: 0.268 alpha: 1];
    CGFloat baseColorRGBA[4];
    [baseColor getRed: &baseColorRGBA[0] green: &baseColorRGBA[1] blue: &baseColorRGBA[2] alpha: &baseColorRGBA[3]];

    UIColor* upperColor = [UIColor colorWithRed: (baseColorRGBA[0] * 0.8 + 0.2) green: (baseColorRGBA[1] * 0.8 + 0.2) blue: (baseColorRGBA[2] * 0.8 + 0.2) alpha: (baseColorRGBA[3] * 0.8 + 0.2)];
    UIColor* lowerColor = [UIColor colorWithRed: (baseColorRGBA[0] * 0.9) green: (baseColorRGBA[1] * 0.9) blue: (baseColorRGBA[2] * 0.9) alpha: (baseColorRGBA[3] * 0.9 + 0.1)];
    UIColor* lightUpColor = [UIColor colorWithRed: (baseColorRGBA[0] * 0.5 + 0.5) green: (baseColorRGBA[1] * 0.5 + 0.5) blue: (baseColorRGBA[2] * 0.5 + 0.5) alpha: (baseColorRGBA[3] * 0.5 + 0.5)];
    UIColor* lightDownColor = [UIColor colorWithRed: (baseColorRGBA[0] * 0.8) green: (baseColorRGBA[1] * 0.8) blue: (baseColorRGBA[2] * 0.8) alpha: (baseColorRGBA[3] * 0.8 + 0.2)];

    //// Gradient Declarations
    NSArray* buttonGradientColors = [NSArray arrayWithObjects:
                                     (id)upperColor.CGColor,
                                     (id)lowerColor.CGColor, nil];
    CGFloat buttonGradientLocations[] = {0, 1};
    CGGradientRef buttonGradient = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef)buttonGradientColors, buttonGradientLocations);
    NSArray* overlayGradientColors = [NSArray arrayWithObjects:
                                      (id)lightUpColor.CGColor,
                                      (id)[UIColor clearColor].CGColor, nil];
    CGFloat overlayGradientLocations[] = {0, 1};
    CGGradientRef overlayGradient = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef)overlayGradientColors, overlayGradientLocations);
    NSArray* gradientColors = [NSArray arrayWithObjects:
                               (id)lightUpColor.CGColor,
                               (id)lightDownColor.CGColor, nil];
    CGFloat gradientLocations[] = {0, 1};
    CGGradientRef gradient = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef)gradientColors, gradientLocations);

    //// Shadow Declarations
    UIColor* buttonShadow = [UIColor blackColor];
    CGSize buttonShadowOffset = CGSizeMake(0.1, 1.1);
    CGFloat buttonShadowBlurRadius = 2;
    UIColor* textShadow = [UIColor blackColor];
    CGSize textShadowOffset = CGSizeMake(0.1, -0.1);
    CGFloat textShadowBlurRadius = 5;

    //// Abstracted Attributes
    NSString* textContent = @"Update";


    //// Back Rectangle Drawing
    UIBezierPath* backRectanglePath = [UIBezierPath bezierPathWithRoundedRect: CGRectMake(48, 53, 120, 23) cornerRadius: 4];
    CGContextSaveGState(context);
    CGContextSetShadowWithColor(context, buttonShadowOffset, buttonShadowBlurRadius, buttonShadow.CGColor);
    CGContextBeginTransparencyLayer(context, NULL);
    [backRectanglePath addClip];
    CGContextDrawLinearGradient(context, gradient, CGPointMake(108, 53), CGPointMake(108, 76), 0);
    CGContextEndTransparencyLayer(context);
    CGContextRestoreGState(context);



    //// Rounded Rectangle Drawing
    UIBezierPath* roundedRectanglePath = [UIBezierPath bezierPathWithRoundedRect: CGRectMake(49, 54, 118, 21) cornerRadius: 3];
    CGContextSaveGState(context);
    [roundedRectanglePath addClip];
    CGContextDrawLinearGradient(context, buttonGradient, CGPointMake(108, 54), CGPointMake(108, 75), 0);
    CGContextRestoreGState(context);


    //// Overlay Drawing
    UIBezierPath* overlayPath = [UIBezierPath bezierPathWithRoundedRect: CGRectMake(48, 53, 120, 23) cornerRadius: 4];
    CGContextSaveGState(context);
    [overlayPath addClip];
    CGContextDrawRadialGradient(context, overlayGradient,
                                CGPointMake(54.72, 38.09), 10,
                                CGPointMake(108, 11.46), 102.2,
                                kCGGradientDrawsBeforeStartLocation | kCGGradientDrawsAfterEndLocation);
    CGContextRestoreGState(context);


    //// Text Drawing
    CGRect textRect = CGRectMake(55, 54, 104, 21);
    UIBezierPath* textPath = [UIBezierPath bezierPathWithRect: textRect];
    CGContextSaveGState(context);
    CGContextSetShadowWithColor(context, textShadowOffset, textShadowBlurRadius, textShadow.CGColor);
    CGContextBeginTransparencyLayer(context, NULL);
    [textPath addClip];
    CGContextDrawLinearGradient(context, buttonGradient, CGPointMake(107, 54), CGPointMake(107, 75), 0);
    CGContextEndTransparencyLayer(context);
    CGContextRestoreGState(context);

    [strokeColor setStroke];
    textPath.lineWidth = 1;
    [textPath stroke];
    CGContextSaveGState(context);
    CGContextSetShadowWithColor(context, textShadowOffset, textShadowBlurRadius, textShadow.CGColor);
    [[UIColor whiteColor] setFill];
    [textContent drawInRect: textRect withFont: [UIFont boldSystemFontOfSize: [UIFont systemFontSize]] lineBreakMode: NSLineBreakByWordWrapping alignment: NSTextAlignmentCenter];
    CGContextRestoreGState(context);



    //// Cleanup
    CGGradientRelease(buttonGradient);
    CGGradientRelease(overlayGradient);
    CGGradientRelease(gradient);
    CGColorSpaceRelease(colorSpace);

    NSLog(@"drawRect exit");



}


@end

Answer 1

使用 Storyboard 时不需要实现 initWithFrame:。事实上， Storyboard将使用 initWithCoder:，因此它甚至不会被调用。

我测试了你的代码，它工作正常，但是，你不是在左上角绘制，而是在 View 中间的某个地方，所以如果你想看到你的按钮，一定要使 View 足够大.

最好画在左上角。