UIView drawRect和initWithFrame [英] UIView drawRect vs initWithFrame

问题描述

我有一个UIView有几个按钮添加到它作为子视图。目前我有drawRect：中的按钮，我听说是一个坏主意，因为drawRect可以调用几次。我试图将这些UIButtons移动到initWithFrame，但他们只是不绘制。我应该如何解决这个问题？

I have a UIView which has several buttons added to it as subviews. Currently I have the buttons in drawRect:, which I have heard is a bad idea because drawRect can be called several times. I tried to move these UIButtons to initWithFrame, but they just don't get drawn. How should I fix this?

我没有使用界面生成器，所以没有NIB文件存在。调用initWithFrame。我通过添加一个NSLog（...）检查，我的NSMutableArrays正在正确初始化。

I am not using interface builder, so there are no NIB files present. The initWithFrame is called. I checked by adding an NSLog(...), and my NSMutableArrays are being properly initialized.

我的initWitFrame：代码目前有很少。

My initWitFrame: code currently has very little. It is

- (id)initWithFrame:(CGRect)frame 
{
    if (self = [super initWithFrame:frame]) 
    {
        results = [[NSMutableArray alloc] init];
        inputs = [[NSMutableArray alloc] init];
        format = [[NSDateFormatter alloc] init];
        [format setDateFormat:@"EEE, MMM dd, yyyy"];
        renc =[[RenameController alloc] init];
    }
    return self;
}

我试图添加一个textlabel，如下所示

I have tried to add a textlabel like the following

#define BOX_WIDTH 155.0
#define BOX_OFFSET 45.00
#define ROW_HEIGHT 27

- (id)initWithFrame:(CGRect)frame 
{
    if (self = [super initWithFrame:frame]) 
    {
        results = [[NSMutableArray alloc] init];
        inputs = [[NSMutableArray alloc] init];
        format = [[NSDateFormatter alloc] init];
        [format setDateFormat:@"EEE, MMM dd, yyyy"];
        renc =[[RenameController alloc] init];

        double row=0.0;
        [self makelabel:@"Start" at:CGRectMake(0, row, BOX_OFFSET, ROW_HEIGHT)];
    }
    return self;
}

-(void) makelabel:(NSString *) str at:(CGRect) rect
{
    UILabel *title = [[UILabel alloc] initWithFrame:rect];
    title.text = str;
    title.textAlignment = UITextAlignmentLeft;
    title.textColor = [UIColor blackColor];
    title.backgroundColor = [UIColor clearColor];
    title.font = [UIFont boldSystemFontOfSize:FONT_SIZE];
    [self addSubview:title];
    [title release];
}

推荐答案

@tonklon是现货。另外，通常的模式是在第三种方法中使用您的自定义初始化代码，例如 -sharedInit ，它在适当的 super initializer：

@tonklon is spot on. Additionally, the usual pattern is to have your custom initialization code in a third method, such as -sharedInit, which is called after the appropriate super initializer:

- (id)sharedInit {
    // do whatever, possibly releasing self on error and returning nil
    return self;
}

- (id)initWithFrame: (CGRect)frame {
    self = [super initWithFrame: frame];
    if (self) {
        self = [self sharedInit];
    }
    return self;
}

- (id)initWithCoder: (NSCoder *)aDecoder {
    self = [super initWithDecoder: aDecoder];
    if (self) {
        self = [self sharedInit];
    }
    return self;
}

这篇关于UIView drawRect和initWithFrame的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！