值得收藏的iOS开发常用代码块

2020-01-18 16:10:45丽君

iOS在当前屏幕获取第一响应


UIWindow * keyWindow = [[UIApplication sharedApplication] keyWindow];
UIView * firstResponder = [keyWindow performSelector:@selector(firstResponder)];

判断对象是否遵循了某协议


if ([self.selectedController conformsToProtocol:@protocol(RefreshPtotocol)])
{
   [self.selectedController performSelector:@selector(onTriggerRefresh)];
}

判断view是不是指定视图的子视图
BOOL isView = [textView isDescendantOfView:self.view]; 

NSArray 快速求总和 最大值 最小值 和 平均值


NSArray *array = [NSArray arrayWithObjects:@"2.0", @"2.3", @"3.0", @"4.0", @"10", nil];
CGFloat sum = [[array valueForKeyPath:@"@sum.floatValue"] floatValue];
CGFloat avg = [[array valueForKeyPath:@"@avg.floatValue"] floatValue];
CGFloat max =[[array valueForKeyPath:@"@max.floatValue"] floatValue];
CGFloat min =[[array valueForKeyPath:@"@min.floatValue"] floatValue];
NSLog(@"%fn%fn%fn%f",sum,avg,max,min);

修改UITextField中Placeholder的文字颜色
[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"]; 

获取一个类的所有子类


+ (NSArray *) allSubclasses
{
  Class myClass = [self class];
  NSMutableArray *mySubclasses = [NSMutableArray array];
  unsigned int numOfClasses;
  Class *classes = objc_copyClassList(&numOfClasses;);
  for (unsigned int ci = 0; ci < numOfClasses; ci++)
  {
    Class superClass = classes[ci];
    do{
      superClass = class_getSuperclass(superClass);
    } while (superClass && superClass != myClass);

    if (superClass)
    {
      [mySubclasses addObject: classes[ci]];
    }
  }
  free(classes);
  return mySubclasses;
}

阿拉伯数字转中文格式


+(NSString *)translation:(NSString *)arebic
{ 
  NSString *str = arebic;
  NSArray *arabic_numerals = @[@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"0"];
  NSArray *chinese_numerals = @[@"一",@"二",@"三",@"四",@"五",@"六",@"七",@"八",@"九",@"零"];
  NSArray *digits = @[@"个",@"十",@"百",@"千",@"万",@"十",@"百",@"千",@"亿",@"十",@"百",@"千",@"兆"];
  NSDictionary *dictionary = [NSDictionary dictionaryWithObjects:chinese_numerals forKeys:arabic_numerals];

  NSMutableArray *sums = [NSMutableArray array];
  for (int i = 0; i < str.length; i ++) {
    NSString *substr = [str substringWithRange:NSMakeRange(i, 1)];
    NSString *a = [dictionary objectForKey:substr];
    NSString *b = digits[str.length -i-1];
    NSString *sum = [a stringByAppendingString:b];
    if ([a isEqualToString:chinese_numerals[9]])
    {
      if([b isEqualToString:digits[4]] || [b isEqualToString:digits[8]])
      {
        sum = b;
        if ([[sums lastObject] isEqualToString:chinese_numerals[9]])
        {
          [sums removeLastObject];
        }
      }else
      {
        sum = chinese_numerals[9];
      }

      if ([[sums lastObject] isEqualToString:sum])
      {
        continue;
      }
    }

    [sums addObject:sum];
  }

  NSString *sumStr = [sums componentsJoinedByString:@""];
  NSString *chinese = [sumStr substringToIndex:sumStr.length-1];
  NSLog(@"%@",str);
  NSLog(@"%@",chinese);
  return chinese;
}