iOS开发使用技巧记录

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• 输入屏幕上移和恢复

// 需要实现UITextFieldDelegate

//在UITextField 编辑之前调用方法
- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    [self animateTextField: textField up: YES];
}
//在UITextField 编辑完成调用方法
- (void)textFieldDidEndEditing:(UITextField *)textField
{
    [self animateTextField: textField up: NO];
}
//视图上移的方法
- (void) animateTextField: (UITextField *) textField up: (BOOL) up
{
    //设置视图上移的距离，单位像素
    const int movementDistance = 100; // tweak as needed
    //三目运算，判定是否需要上移视图或者不变
    int movement = (up ? -movementDistance : movementDistance);
    //设置动画的名字
    [UIView beginAnimations: @"Animation" context: nil];
    //设置动画的开始移动位置
    [UIView setAnimationBeginsFromCurrentState: YES];
    //设置动画的间隔时间
    [UIView setAnimationDuration: 0.20];
    //设置视图移动的位移
    self.view.frame = CGRectOffset(self.view.frame, 0, movement);
    //设置动画结束
    [UIView commitAnimations];
}

• 点击空白隐藏键盘

//隐藏键盘
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    [self.view endEditing:YES];
}

• AutoLayout
  iOS 8 AutoLayout与Size Class
  

  • 部分方法名

    
    [myView setAutoresizingMask:UIViewAutoresizing];
• 字符串加密

   //首先导入系统库函数
    #import <CommonCrypto/CommonDigest.h>

   //sha256加密
+ (NSString *)getSha1String:(NSString *)srcString{
    const char *cstr = [srcString UTF8String];
    NSData *data = [NSData dataWithBytes:cstr length:srcString.length];
    uint8_t digest[CC_SHA256_DIGEST_LENGTH];
    CC_SHA256(data.bytes, (int)data.length, digest);
    NSMutableString* result = [NSMutableString stringWithCapacity:CC_SHA256_DIGEST_LENGTH * 2];
    for(int i = 0; i < CC_SHA256_DIGEST_LENGTH; i++) {
        [result appendFormat:@"%02x", digest[i]];
    }
    return result;
}

  //MD5加密
+ (NSString *)getMd5_32Bit_String:(NSString *)srcString{
    const char *cstr = [srcString UTF8String];
    uint8_t digest[CC_MD5_DIGEST_LENGTH];
    CC_MD5(cstr, (int)strlen(cstr), digest);
    NSMutableString *result = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH*2];
    for (int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {
        [result appendFormat:@"%02x",digest[i]];
    }
    return result;
}

• 将UIColor转换为UIImage

  // 根据颜色生成一张尺寸为1*1的相同颜色图片
+ (UIImage *)imageWithColor:(UIColor *)color
{
    // 描述矩形
    CGRect rect=CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);

    // 开启位图上下文
     UIGraphicsBeginImageContext(rect.size);
    // 获取位图上下文
    CGContextRef context = UIGraphicsGetCurrentContext();
    // 使用color演示填充上下文
    CGContextSetFillColorWithColor(context, [color CGColor]);
    // 渲染上下文
    CGContextFillRect(context, rect);
    // 从上下文中获取图片
    UIImage *theImage = UIGraphicsGetImageFromCurrentImageContext();
    // 结束上下文
    UIGraphicsEndImageContext();

    return theImage;
 }

• 设置TarBar顶部线条颜色

  //设置TabBar顶部线的颜色
    [self.tabBar setBackgroundImage:[[UIImage alloc] init]];
    [self.tabBar setShadowImage:[UIImage imageWithColor:RGBA(218, 218, 218, 1)]];

• 使View的部分位置不响应事件,传递给下一层

    //重写View的- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event；
    - (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event{
        return !CGRectContainsPoint(self.tableHeaderView.frame, point);
    }