Container

介绍

Container 容器控件，包含一个子Widget，具备alignment、padding等属性，方便布局摆放child

类结构

属性

child

子控件

alignment

对齐方式

 /// The top left corner.
  static const Alignment topLeft = Alignment(-1.0, -1.0);
  /// The center point along the top edge.
  static const Alignment topCenter = Alignment(0.0, -1.0);
  /// The top right corner.
  static const Alignment topRight = Alignment(1.0, -1.0);
  /// The center point along the left edge.
  static const Alignment centerLeft = Alignment(-1.0, 0.0);
  /// The center point, both horizontally and vertically.
  static const Alignment center = Alignment(0.0, 0.0);
  /// The center point along the right edge.
  static const Alignment centerRight = Alignment(1.0, 0.0);
  /// The bottom left corner.
  static const Alignment bottomLeft = Alignment(-1.0, 1.0);
  /// The center point along the bottom edge.
  static const Alignment bottomCenter = Alignment(0.0, 1.0);
  /// The bottom right corner.
  static const Alignment bottomRight = Alignment(1.0, 1.0);

color 和 decoration

设置背景色或背景

• 两者无法共存

  assert(color == null || decoration == null,
    'Cannot provide both a color and a decoration\n'
    'The color argument is just a shorthand for "decoration: new BoxDecoration(color: color)".'
  ),
  decoration = decoration ?? (color != null ? BoxDecoration(color: color) : null),

foregroundDecoration

前景设置

margin

边距设置

constraints

布局约束

transform

矩阵变换