<itemvalue="A builder that positions the [firstChild] and [secondChild] widgets. The widget returned by this method is wrapped in an [AnimatedSize]. By default, this uses [AnimatedCrossFade.defaultLayoutBuilder], which uses a [Stack] and aligns the `bottomChild` to the top of the stack while providing the `topChild` as the non-positioned child to fill the provided constraints. This works well when the [AnimatedCrossFade] is in a position to change size and when the children are not flexible. However, if the children are less fussy about their sizes (for example a [CircularProgressIndicator] inside a [Center]), or if the [AnimatedCrossFade] is being forced to a particular size, then it can result in the widgets jumping about when the cross-fade state is changed."/>
<itemvalue="Typically, the Directionality widget is introduced by the MaterialApp or WidgetsApp widget at the top of your application widget tree. It determines the ambient reading direction and is used, for example, to determine how to lay out text, how to interpret "start" and "end" values, and to resolve EdgeInsetsDirectional, AlignmentDirectional, and other Directional objects. Instead of providing a Directionality widget, another solution would be passing a non-directional 'alignment', or an explicit 'textDirection', to the Stack."/>
<itemvalue="Returns true if [this] occurs at the same moment as [other]. The comparison is independent of whether the time is in UTC or in the local time zone. ```dart var now = DateTime.now(); var later = now.add(const Duration(seconds: 5)); assert(!later.isAtSameMomentAs(now)); assert(now.isAtSameMomentAs(now)); This relation stays the same, even when changing timezones. assert(!later.isAtSameMomentAs(now.toUtc())); assert(!later.toUtc().isAtSameMomentAs(now)); assert(now.toUtc().isAtSameMomentAs(now)); assert(now.isAtSameMomentAs(now.toUtc())); ```"/>
<itemvalue="bar Width"/>
<itemvalue="is Curved"/>
<itemvalue="[x] determines cartesian (axis based) horizontally position 0 means most left point of the chart"/>
<itemvalue="[y] determines cartesian (axis based) vertically position 0 means most bottom point of the chart"/>
<itemvalue="Fl Spot"/>
<itemvalue="navigate"/>
<itemvalue="prevent"/>
<itemvalue="magnification"/>
<itemvalue="diameter Ratio"/>
<itemvalue="squeeze"/>
<itemvalue="A default selection overlay for [CupertinoPicker]s. It draws a gray rounded rectangle to match the picker visuals introduced in iOS 14. This widget is typically only used in [CupertinoPicker.selectionOverlay]. In an iOS 14 multi-column picker, the selection overlay is a single rounded rectangle that spans the entire multi-column picker. To achieve the same effect using [CupertinoPickerDefaultSelectionOverlay], the additional margin and corner radii on the left or the right side can be disabled by turning off [capLeftEdge] and [capRightEdge], so this selection overlay visually connects with selection overlays of adjoining [CupertinoPicker]s (i.e., other "column"s). See also: [CupertinoPicker], which uses this widget as its default [CupertinoPicker.selectionOverlay]."/>
<itemvalue="Creates an iOS 14 style selection overlay that highlights the magnified area (or the currently selected item, depending on how you described it elsewhere) of a [CupertinoPicker]. The [background] argument default value is [CupertinoColors.tertiarySystemFill]. It must be non-null. The [capLeftEdge] and [capRightEdge] arguments decide whether to add a default margin and use rounded corners on the left and right side of the rectangular overlay. Default to true and must not be null."/>
<itemvalue="Evaluates a JavaScript expression in the context of the current page. On Android returns the evaluation result as a JSON formatted string. On iOS depending on the value type the return value would be one of: - For primitive JavaScript types: the value string formatted (e.g JavaScript 100 returns '100'). - For JavaScript arrays of supported types: a string formatted NSArray(e.g '(1,2,3), note that the string for NSArray is formatted and might contain newlines and extra spaces.'). - Other non-primitive types are not supported on iOS and will complete the Future with an error. The Future completes with an error if a JavaScript error occurred, or on iOS, if the type of the evaluated expression is not supported as described above. When evaluating Javascript in a [WebView], it is best practice to wait for the [WebView.onPageFinished] callback. This guarantees all the Javascript embedded in the main frame HTML has been loaded."/>
<itemvalue="The center slice for a nine-patch image. The region of the image inside the center slice will be stretched both horizontally and vertically to fit the image into its destination. The region of the image above and below the center slice will be stretched only horizontally and the region of the image to the left and right of the center slice will be stretched only vertically. The stretching will be applied in order to make the image fit into the box specified by [fit]. When [centerSlice] is not null, [fit] defaults to [BoxFit.fill], which distorts the destination image size relative to the image's original aspect ratio. Values of [BoxFit] which do not distort the destination image size will result in [centerSlice] having no effect (since the nine regions of the image will be rendered with the same scaling, as if it wasn't specified)."/>
<itemvalue="covariant"/>
<itemvalue="verification Codes"/>
<itemvalue="A [TextInputFormatter] can be optionally injected into an [EditableText] to provide as-you-type validation and formatting of the text being edited. Text modification should only be applied when text is being committed by the IME and not on text under composition (i.e., only when [TextEditingValue.composing] is collapsed). See also the [FilteringTextInputFormatter], a subclass that removes characters that the user tries to enter if they do, or do not, match a given pattern (as applicable). To create custom formatters, extend the [TextInputFormatter] class and implement the [formatEditUpdate] method. Handling emojis and other complex characters {@macro flutter.widgets.EditableText.onChanged} See also: [EditableText] on which the formatting apply. [FilteringTextInputFormatter], a provided formatter for filtering characters."/>
<itemvalue="Text Input Formatter"/>
<itemvalue="过时"/>
<itemvalue="Refactory"/>
<itemvalue="ecg binary"/>
<itemvalue="Converts the given JSON-string [input] to its corresponding object. Parsed JSON values are of the types [num], [String], [bool], [Null], [List]s of parsed JSON values or [Map]s from [String] to parsed JSON values. If `this` was initialized with a reviver, then the parsing operation invokes the reviver on every object or list property that has been parsed. The arguments are the property name ([String]) or list index ([int]), and the value is the parsed value. The return value of the reviver is used as the value of that property instead the parsed value. Throws [FormatException] if the input is not valid JSON text."/>