IOS不用AutoLayout也能实现自动布局的类(2)----MyFrameLayout 框架布局

我们知道，在IOS中我们要想进行视图的各方向的停靠，需要用到autoresizingMask，以及不停的计算应该停靠的位置，也就是计算frame中的x,y,width,height，这样大量的编码导致计算繁琐而且容易出错，因此我这里推出了另外新的布局模式MyFrameLayout。这个布局可以让子视图实现左中右，上中下，填充等功能的布局，同时还可以设置停靠的布局的位置的边距，我们对子视图扩展出了停靠位置的属性：

@property(nonatomic,assign)MarignGravity marginGravity;

这个属性用来控制子视图停靠在MyFrameLayout的方位，这些方位可以是如下方位的或组合：

    MGRAVITY_NONE  //不采用停靠模式

    MGRAVITY_HORZ_LEFT  //水平居左

    MGRAVITY_HORZ_CENTER  //水平居中

    MGRAVITY_HORZ_RIGHT  //水平居右

    MGRAVITY_HORZ_FILL  //水平填充整个布局，视图会有拉伸

    MGRAVITY_VERT_TOP  //垂直居上

    MGRAVITY_VERT_CENTER //垂直居中

    MGRAVITY_VERT_BOTTOM  //垂直居下

     MGRAVITY_VERT_FILL  //垂直填充整个布局，视图会有拉伸

    MGRAVITY_CENTER  //整个视图居中

    MGRAVITY_FILL  //整个视图填满布局视图

除了可以让子视图停靠在布局的方位外，还可以指定子视图离停靠位置的边距，这个可以通过扩展的视图的四个属性：

@property(nonatomic,assign)CGFloat topMargin;

@property(nonatomic,assign)CGFloat leftMargin;

@property(nonatomic,assign)CGFloat bottomMargin;

@property(nonatomic,assign)CGFloat rightMargin;

 

这四个属性用来设置视图离停靠位置的四个距离。同时MyFrameLayout中还提供一个padding的属性用来控制整体的子视图离自己的边距。

因为这个布局的使用比较简单，下面直接可以看图：

对应的代码如下：

[objc] view plaincopy

MyFrameLayout *fl = [[MyFrameLayout alloc] initWithFrame:self.view.bounds];
  fl.autoresizingMask =  UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
  fl.padding = UIEdgeInsetsMake(20, 20, 20, 20);
  fl.backgroundColor = [UIColor grayColor];

  //显示全屏
  UILabel *fill = UILabel.new;
  fill.text = @"                fill";
 // fill.textAlignment = NSTextAlignmentCenter;
  fill.backgroundColor = [UIColor blueColor];
  fill.marginGravity = MGRAVITY_FILL;
  [fl addSubview:fill];



  //左右填充。
  UILabel *horzFill = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 0, 120)];
  horzFill.text = @"Horz Fill";
  horzFill.textAlignment = NSTextAlignmentCenter;
  horzFill.backgroundColor = [UIColor greenColor];
  horzFill.marginGravity = MGRAVITY_HORZ_FILL;
  [fl addSubview:horzFill];


  //左右居中
  UILabel *horzCenter = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 100, 50)];
  horzCenter.text = @"Horz Center";
  horzCenter.backgroundColor = [UIColor whiteColor];
  horzCenter.marginGravity = MGRAVITY_HORZ_CENTER;
  [fl addSubview:horzCenter];


  //左上
  UILabel *topLeft = UILabel.new;
  topLeft.text = @"topLeft";
  [topLeft sizeToFit];
  topLeft.backgroundColor = [UIColor whiteColor];
  topLeft.marginGravity = MGRAVITY_HORZ_LEFT | MGRAVITY_VERT_TOP;
  [fl addSubview:topLeft];

  //左中
  UILabel *centerLeft = UILabel.new;
  centerLeft.text = @"centerLeft";
  [centerLeft sizeToFit];
  centerLeft.backgroundColor = [UIColor whiteColor];
  centerLeft.marginGravity = MGRAVITY_HORZ_LEFT | MGRAVITY_VERT_CENTER;
  [fl addSubview:centerLeft];


  //左下
  UILabel *bottomLeft = UILabel.new;
  bottomLeft.text = @"bottomLeft";
  [bottomLeft sizeToFit];
  bottomLeft.backgroundColor = [UIColor whiteColor];
  bottomLeft.marginGravity = MGRAVITY_HORZ_LEFT | MGRAVITY_VERT_BOTTOM;
  [fl addSubview:bottomLeft];


  //中上
  UILabel *topCenter = UILabel.new;
  topCenter.text = @"topCenter";
  [topCenter sizeToFit];
  topCenter.backgroundColor = [UIColor greenColor];
  topCenter.marginGravity = MGRAVITY_HORZ_CENTER | MGRAVITY_VERT_TOP;
  [fl addSubview:topCenter];


  //中中。
  UILabel *centerCenter = UILabel.new;
  centerCenter.text = @"centerCenter";
  [centerCenter sizeToFit];
  centerCenter.backgroundColor = [UIColor greenColor];
  centerCenter.marginGravity = MGRAVITY_HORZ_CENTER | MGRAVITY_VERT_CENTER;
  [fl addSubview:centerCenter];


  //中下
  UILabel *bottomCenter = UILabel.new;
  bottomCenter.text = @"bottomCenter";
  [bottomCenter sizeToFit];
  bottomCenter.backgroundColor = [UIColor greenColor];
  bottomCenter.marginGravity = MGRAVITY_HORZ_CENTER | MGRAVITY_VERT_BOTTOM;
  [fl addSubview:bottomCenter];


  //右上
  UILabel *topRight = UILabel.new;
  topRight.text = @"topRight";
  [topRight sizeToFit];
  topRight.backgroundColor = [UIColor greenColor];
  topRight.marginGravity = MGRAVITY_HORZ_RIGHT | MGRAVITY_VERT_TOP;
  [fl addSubview:topRight];


  //右中
  UILabel *centerRight = UILabel.new;
  centerRight.text = @"centerRight";
  [centerRight sizeToFit];
  centerRight.backgroundColor = [UIColor greenColor];
  centerRight.marginGravity = MGRAVITY_HORZ_RIGHT | MGRAVITY_VERT_CENTER;
  [fl addSubview:centerRight];


  UILabel *bottomRight = UILabel.new;
  bottomRight.text = @"bottomRight";
  [bottomRight sizeToFit];
  bottomRight.backgroundColor = [UIColor greenColor];
  bottomRight.marginGravity = MGRAVITY_HORZ_RIGHT | MGRAVITY_VERT_BOTTOM;
  [fl addSubview:bottomRight];


  //居中显示。
  UILabel *center = UILabel.new;
  center.text = @"center";
  [center sizeToFit];
  center.backgroundColor = [UIColor redColor];
  center.marginGravity = MGRAVITY_CENTER;
  center.leftMargin = 30;
  center.rightMargin = 30;
  center.topMargin = 30;
  center.bottomMargin = 30;
  [fl addSubview:center];


  [self.view addSubview:fl];

 从代码中我们可以看到每个视图只需要设置marginGravity的对应的停靠的位置，以及设置对应的xxxMargin边距，还有设置MyFrameLayout的padding值来设置里面里面的子视图离自己的边距。

总结：

   对于那些希望固定在某个位置的子视图来说，我们可以通过将视图加入到MyFrameLayout中来实现。