正則十八式-第四式 挫骨揚灰

• 正則十八式-第一式：直搗黃龍
• 正則十八式-第二式：控鶴擒龍
• 正則十八式-第三式：龍躍於淵
• 正則十八式-第四式 挫骨揚灰

Flutter大軍來到，Container戰將率領字符大軍來到，師徒二人漸入絕境。

class Container extends StatelessWidget {
  /// Creates a widget that combines common painting, positioning, and sizing widgets.
  ///
  /// The `height` and `width` values include the padding.
  ///
  /// The `color` argument is a shorthand for `decoration: new
  /// BoxDecoration(color: color)`, which means you cannot supply both a `color`
  /// and a `decoration` argument. If you want to have both a `color` and a
  /// `decoration`, you can pass the color as the `color` argument to the
  /// `BoxDecoration`.
  Container({
    Key key,
    this.alignment,
    this.padding,
    Color color,
    Decoration decoration,
    this.foregroundDecoration,
    double width,
    double height,
    BoxConstraints constraints,
    this.margin,
    this.transform,
    this.child,
  }) : assert(margin == null || margin.isNonNegative),
       assert(padding == null || padding.isNonNegative),
       assert(decoration == null || decoration.debugAssertIsValid()),
       assert(constraints == null || constraints.debugAssertIsValid()),
       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),
       constraints =
        (width != null || height != null)
          ? constraints?.tighten(width: width, height: height)
            ?? BoxConstraints.tightFor(width: width, height: height)
          : constraints,
       super(key: key);

  /// The [child] contained by the container.
  ///
  /// If null, and if the [constraints] are unbounded or also null, the
  /// container will expand to fill all available space in its parent, unless
  /// the parent provides unbounded constraints, in which case the container
  /// will attempt to be as small as possible.
  ///
  /// {@macro flutter.widgets.child}
  final Widget child;

  /// Align the [child] within the container.
  ///
  /// If non-null, the container will expand to fill its parent and position its
  /// child within itself according to the given value. If the incoming
  /// constraints are unbounded, then the child will be shrink-wrapped instead.
  ///
  /// Ignored if [child] is null.
  ///
  /// See also:
  ///
  ///  * [Alignment], a class with convenient constants typically used to
  ///    specify an [AlignmentGeometry].
  ///  * [AlignmentDirectional], like [Alignment] for specifying alignments
  ///    relative to text direction.
  final AlignmentGeometry alignment;

  /// Empty space to inscribe inside the [decoration]. The [child], if any, is
  /// placed inside this padding.
  ///
  /// This padding is in addition to any padding inherent in the [decoration];
  /// see [Decoration.padding].
  final EdgeInsetsGeometry padding;

  /// The decoration to paint behind the [child].
  ///
  /// A shorthand for specifying just a solid color is available in the
  /// constructor: set the `color` argument instead of the `decoration`
  /// argument.
  ///
  /// The [child] is not clipped to the decoration. To clip a child to the shape
  /// of a particular [ShapeDecoration], consider using a [ClipPath] widget.
  final Decoration decoration;

  /// The decoration to paint in front of the [child].
  final Decoration foregroundDecoration;

  /// Additional constraints to apply to the child.
  ///
  /// The constructor `width` and `height` arguments are combined with the
  /// `constraints` argument to set this property.
  ///
  /// The [padding] goes inside the constraints.
  final BoxConstraints constraints;

  /// Empty space to surround the [decoration] and [child].
  final EdgeInsetsGeometry margin;

  /// The transformation matrix to apply before painting the container.
  final Matrix4 transform;


複製代碼

廟外，Container自報家門:吾乃Widget家族戰將，Container，扇仙老兒速來一戰。
捷特凌然出戰，道一句:呔，吾師名號豈容汝等污穢。出手即是一招龍躍於淵，將對手團團圍住，正在升龍之時。
Container一笑:這招不差，惋惜火候不足 。僅一掙，就破了這招。

藏扇仙出，bgm起，以心傳心:徒兒，爲師如今深中靈蛛之毒，氣力不濟，這第四式也只能使出八成威力，並且只能使用一次。你能學到什麼程度，還要看你造化。
只見廟前，藏扇仙身發藍光，納天地靈氣，運氣於掌，一時間飛沙走石，
呵道:正則十八式，第四式-挫骨... 雷電交加，天地共震，container瞬間粉身碎骨，留下了一堆渣渣。

Widget---child
AlignmentGeometry---alignment
EdgeInsetsGeometry---padding
Decoration---decoration
Decoration---foregroundDecoration
BoxConstraints---constraints
EdgeInsetsGeometry---margin
Matrix4---transform
複製代碼

藏扇仙：...揚灰。

屬性	屬性類型
foregroundDecoration	Decoration
padding	EdgeInsetsGeometry
margin	EdgeInsetsGeometry
transform	Matrix4
alignment	AlignmentGeometry
decoration	Decoration
constraints	BoxConstraints
child	Widget

---

氣勁迴流，扇仙一口嘔紅，臥倒在地。捷特:師傅，你感受如何？ 藏扇仙:無礙，這一式，你看得如何？ 捷特:這招太厲害了，不過不瞞您說……剛纔風大，沙子迷眼了，沒看清。」
此時遠處漸現Text大旗，藏扇仙:唉，天意啊，天意，現在追兵已至，吾命休矣。
捷特:師傅莫灰心，從這殘骸中，您的氣勁尚存，我似能領略一二。您將Container中的屬性與類型分離出來

private static void regexWidget(String target) {
    Map<String,String> fieldMap= new HashMap();
    String regex="final (?<type>\\w*) (?<name>\\w*);";
    Pattern pattern = Pattern.compile(regex);
    Matcher matcher = pattern.matcher(target);
    while (matcher.find()){
        fieldMap.put(matcher.group("name"),matcher.group("type"));
    }
    createTable(fieldMap);
}
複製代碼

而後將分理處的碎片進行重組,成爲markdowon的字符串

private static void createTable(Map<String,String> fieldMap) {
    String title="屬性 | 屬性類型\n";
    String syb="---|---\n";
  StringBuilder sb=  new StringBuilder(title);
  sb.append(syb);
    fieldMap.forEach((k,v)->{
        sb.append(k).append("|").append(v).append("\n");
    });
    System.out.println(sb.toString());
}
複製代碼

藏扇仙:「說得不差，這挫骨揚灰重在一挫，一揚。將對方粉碎後，提取有用信息，進行重建。」

屬性 | 屬性類型
---|---
foregroundDecoration|Decoration
padding|EdgeInsetsGeometry
margin|EdgeInsetsGeometry
transform|Matrix4
alignment|AlignmentGeometry
decoration|Decoration
constraints|BoxConstraints
child|Widget
複製代碼

---

Text來到，派出TextStyle大將，捷特應戰，便出一招挫骨揚灰

屬性	屬性類型
textBaseline	TextBaseline
backgroundColor	Color
decorationStyle	TextDecorationStyle
color	Color
wordSpacing	double
decorationThickness	double
letterSpacing	double
foreground	Paint
fontStyle	FontStyle
locale	Locale
decorationColor	Color
fontFamily	String
_package	String
background	Paint
inherit	bool
fontSize	double
debugLabel	String
decoration	TextDecoration
fontWeight	FontWeight
height	double

---

Text上陣，捷特應戰，一招挫骨揚灰

屬性	屬性類型
softWrap	bool
data	String
textAlign	TextAlign
semanticsLabel	String
textWidthBasis	TextWidthBasis
locale	Locale
textDirection	TextDirection
textScaleFactor	double
overflow	TextOverflow
strutStyle	StrutStyle
maxLines	int
textSpan	InlineSpan
style	TextStyle

---

捷特:師傅，我似領悟了要訣，不知是否能夠直攻widgets大本營，一舉殲滅？
藏扇仙:你看這，火候欠佳，這渣子不太純正，你還差得遠呢。
捷特:那第五式呢?
藏扇仙:學會第五式-七進七出，你倒能夠到Flutter的SDK找到widgets大本營，
經過文件的循環讀取，來個火燒連營，一舉殲滅。
複製代碼

---

後記

1----本文由張風捷特烈原創,轉載請註明
2----若是有什麼想要交流的,歡迎留言。也能夠加微信:zdl1994328
3----我的能力有限，若有不正之處歡迎你們批評指證，一定虛心改正
4----看到這裏，我在此感謝你的喜歡與支持,掃碼關注-編程之王