IOS开发基础知识--碎片43

1：增加手势进行左划效果，针对视图并修改其中一个的坐标，菜单用隐藏跟显示

@property(strong,nonatomic)UISwipeGestureRecognizer *recognizer;

self.recognizer = [[ UISwipeGestureRecognizer alloc ] initWithTarget:self action:@selector (handleSwipeFrom:)];

[self.recognizer setDirection:(UISwipeGestureRecognizerDirectionLeft)];

[self addGestureRecognizer :self.recognizer];

- (void)handleSwipeFrom:( UISwipeGestureRecognizer *)sender{if (sender.direction == UISwipeGestureRecognizerDirectionLeft )

    {

        self.rightButton.hidden=NO;

        [self.recognizer setDirection:(UISwipeGestureRecognizerDirectionRight)];

        [self.valueLabel mas_remakeConstraints:^(MASConstraintMaker *make) {

            make.right.mas_equalTo(self.rightButton.left).with.offset(-);

            make.centerY.mas_equalTo(self).with.offset();

            make.size.mas_equalTo(CGSizeMake(Main_Screen_Width-, ));

        }];

        [self.valueLabel layoutIfNeeded];

    }

    else

    {

        self.rightButton.hidden=YES;

        [self.recognizer setDirection:(UISwipeGestureRecognizerDirectionLeft)];

        [self.valueLabel mas_remakeConstraints:^(MASConstraintMaker *make) {

            make.right.mas_equalTo(self.right).with.offset(-);

            make.centerY.mas_equalTo(self).with.offset();

            make.size.mas_equalTo(CGSizeMake(Main_Screen_Width-, ));

        }];

        [self.valueLabel layoutIfNeeded];

    }

}

2:属性名以new开头解决方式

@property (nonatomic,copy) NSString *new_Passwd;

像上面这样写法会报错，可以替换成

@property (nonatomic,copy,getter = theNewPasswd) NSString *new_Passwd;

3：单例类一些注意事项

如果allocWithZone里面的代码不写，用以下三种创建的实例还是三种，不符合我们对单例的运用，当然如果你只针对[HLTestObject sharedInstance]进行实例化时，就是一直满足；把初始化的属性对象放在sharedInstance里面，如果放在init里面进行初始化也会出现不一样的情景；

HLTestObject *objct1 = [HLTestObject sharedInstance];

NSLog(@"%@",objct1);

HLTestObject *objc2 = [[HLTestObject alloc] init];

NSLog(@"%@",objc2);

HLTestObject *objc3 = [HLTestObject new];

NSLog(@"%@",objc3);

声明属性：

@property (assign, nonatomic)   int  height;

@property (strong, nonatomic)   NSObject  *object;

@property (strong, nonatomic)   NSMutableArray  *arrayM;

代码内容：

static HLTestObject *instance = nil;

+ (instancetype)sharedInstance

{

    static dispatch_once_t onceToken;

    dispatch_once(&onceToken, ^{

        instance = [[[self class] alloc] init];

        instance.height = ;

        instance.object = [[NSObject alloc] init];

        instance.arrayM = [[NSMutableArray alloc] init];

    });

    return instance;

}

+ (instancetype)allocWithZone:(struct _NSZone *)zone

{

    static dispatch_once_t onceToken;

    dispatch_once(&onceToken, ^{

        instance = [super allocWithZone:zone];

    });

    return instance;

}

- (NSString *)description

{

    NSString *result = @"";

    result = [result stringByAppendingFormat:@"<%@: %p>",[self class], self];

    result = [result stringByAppendingFormat:@" height = %d,",self.height];

    result = [result stringByAppendingFormat:@" arrayM = %p,",self.arrayM];

    result = [result stringByAppendingFormat:@" object = %p,",self.object];

    return result;

}

4:UITextField实现左侧空出一定的边距

就是通过uitextfield的leftview来实现的，同时要设置leftviewmode。

如果设置左右边距，需要再加上rightView功能

-(void)setTextFieldLeftPadding:(UITextField *)textField forWidth:(CGFloat)leftWidth

{

    CGRect frame = textField.frame;

    frame.size.width = leftWidth;

    UIView *leftview = [[UIView alloc] initWithFrame:frame];

    textField.leftViewMode = UITextFieldViewModeAlways;

    textField.leftView = leftview;

}

5:UICollectionView异步加载的实例

-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath

{

    static NSString * CellIdentifier = @"Event";

    EventCollectionViewCell *cell  = [collectionView dequeueReusableCellWithReuseIdentifier:CellIdentifier forIndexPath:indexPath];

    Event *event = [events objectAtIndex:indexPath.item];  // replace "Event" with whatever class you use for your items实体

    cell.eventTitle.text = [event objectForKey:@"title"];

    cell.eventImage.image = [event objectForKey:@"image"];

    if (cell.eventImage.image == nil) {

        NSString *imageUrl = [[[events objectAtIndex:indexPath.item] objectForKey:@"photo"] objectForKey:@"url"];

        dispatch_queue_t imageFetchQ = dispatch_queue_create("image fetched", NULL);

        dispatch_async(imageFetchQ, ^{

            __weak UICollectionView *weakCollection;

            NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:imageUrl]];

            UIImage *image = [UIImage imageWithData:imageData];

            if (image)

            {

                dispatch_async(dispatch_get_main_queue(), ^{

                    [event setObject:image forKey:@"image"]; // updating the model here

                    [weakCollection reloadItemsAtIndexPaths:@[indexPath]];

                });

            }

        });

    }

    return cell;

}

6：如何拿到别人APP图片

a：打开你Mac上的iTunes，点击我的应用, 找到刚下载好的应用, 右击在finder中显示

b：按Enter(回车键), 修改微信ipa文件的后缀为.zip, 即把微信 6.3.22.ipa变成微信 6.3.22.zip, 此处会有一个提示, 问你是否确定修改扩展名, 点击使用.zip即可

c：直接双击zip进行解压, 打开解压好的文件夹, 进入Payload文件夹此时, 就拿到了大多数的资源. 包括css, js, 图片, MP3/4, 字体,xib等等资源

d：取Assets.car中的资源（工具下载地址: http://pan.baidu.com/s/1kUVAT7p 提取密码: qrt5）

e：我们在上面的E步骤所在的文件夹处搜索Assets.car即可直接将Assets.car拖入其中即可, 对, 拖进去就行了，点击start, 完成后, 点击Output Dir即可（ iOS APP中所有资源 = Assets.car + .api文件解压）

巴特西

IOS开发基础知识--碎片43

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