<p>ExpansionTiles can used to produce two-level or multi-level lists.</p> <p>container-fluid]( row]( col-md-4]( panel panel-default]( panel-bodypadding: 16px 32px;]( token operator]( token function](n](EntryItemtoken punctuation](o]((n](datatoken punctuation](o]([n](indextoken punctuation](o](token punctuation](]token punctuation]()token punctuation](,token punctuation]( nl](itemCounttoken punctuation](:token punctuation]( n](datatoken punctuation](o](.na](lengthtoken punctuation](o](, token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token punctuation](o](token punctuation]()token punctuation](;token punctuation]( token punctuation](o](} token punctuation](o](}</p> <p>token commentspellcheck="true](c1](// One entry in the multilevel list displayed by this app. token keyword](kd](class token class-name](nc](Entry token punctuation](o]({ token function](n](Entrytoken punctuation](o]((token keyword](k](thistoken punctuation](o](.na](titletoken punctuation](o](, token punctuation](o]([token keyword](k](thistoken punctuation](o](.na](children token operator](o](= token keyword](kd](const token operator](o](token punctuation]([token punctuation](]token punctuation](]token punctuation]()token punctuation](;token punctuation](</p> <p>token keyword](kd](final kt](String n](titletoken punctuation](o](; token keyword](kd](final n](Listtoken operator](o]( n](childrentoken punctuation](o](; token punctuation](o](}</p> <p>token commentspellcheck="true](c1](// The entire multilevel list displayed by this app. token keyword](kd](final n](Listtoken operator](o]( n](data token operator](o](= token operator](o](token punctuation]([token punctuation]( token function](n](Entrytoken punctuation](o](( token string](s]('Chapter A'token punctuation](o](, token operator](o](token punctuation]([token punctuation]( token function](n](Entrytoken punctuation](o](( token string](s]('Section A0'token punctuation](o](, token operator](o](token punctuation]([token punctuation]( token function](n](Entrytoken punctuation](o]((token string](s]('Item A0.1'token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token function](n](Entrytoken punctuation](o]((token string](s]('Item A0.2'token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token function](n](Entrytoken punctuation](o]((token string](s]('Item A0.3'token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token punctuation](o](token punctuation](]token punctuation](,token punctuation]( token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token function](n](Entrytoken punctuation](o]((token string](s]('Section A1'token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token function](n](Entrytoken punctuation](o]((token string](s]('Section A2'token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token punctuation](o](token punctuation](]token punctuation](,token punctuation]( token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token function](n](Entrytoken punctuation](o](( token string](s]('Chapter B'token punctuation](o](, token operator](o](token punctuation]([token punctuation]( token function](n](Entrytoken punctuation](o]((token string](s]('Section B0'token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token function](n](Entrytoken punctuation](o]((token string](s]('Section B1'token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token punctuation](o](token punctuation](]token punctuation](,token punctuation]( token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token function](n](Entrytoken punctuation](o](( token string](s]('Chapter C'token punctuation](o](, token operator](o](token punctuation]([token punctuation]( token function](n](Entrytoken punctuation](o]((token string](s]('Section C0'token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token function](n](Entrytoken punctuation](o]((token string](s]('Section C1'token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token function](n](Entrytoken punctuation](o](( token string](s]('Section C2'token punctuation](o](, token operator](o](token punctuation]([token punctuation]( token function](n](Entrytoken punctuation](o]((token string](s]('Item C2.0'token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token function](n](Entrytoken punctuation](o]((token string](s]('Item C2.1'token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token function](n](Entrytoken punctuation](o]((token string](s]('Item C2.2'token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token function](n](Entrytoken punctuation](o]((token string](s]('Item C2.3'token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token punctuation](o](token punctuation](]token punctuation](,token punctuation]( token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token punctuation](o](token punctuation](]token punctuation](,token punctuation]( token punctuation](o](token punctuation]()token punctuation](,token punctuation]( token punctuation](o](token punctuation](]token punctuation](;token punctuation](</p> <p>token commentspellcheck="true](c1](// Displays one Entry. If the entry has children then it's displayed token commentspellcheck="true](c1](// with an ExpansionTile. token keyword](kd](class token class-name](nc](EntryItem token keyword](kd](extends token class-name](n](StatelessWidget token punctuation](o]({ token keyword](kd](const token function](n](EntryItemtoken punctuation](o]((token keyword](k](thistoken punctuation](o](.na](entrytoken punctuation](o](token punctuation]()token punctuation](;token punctuation](</p> <p>token keyword](kd](final n](Entry n](entrytoken punctuation](o](;</p> <p>n](Widget token function](n](_buildTilestoken punctuation](o]((n](Entry n](roottoken punctuation](o]() token punctuation](o]({ token keyword](k](if token punctuation](o]((n](roottoken punctuation](o](.na](childrentoken punctuation](o](.na](isEmptytoken punctuation](o]() token keyword](k](return token function](n](ListTiletoken punctuation](o]((nl](titletoken punctuation](:token punctuation]( token function](n](Texttoken punctuation](o]((n](roottoken punctuation](o](.na](titletoken punctuation](o](token punctuation]()token punctuation]()token punctuation](;token punctuation]( token keyword](k](return token function](n](ExpansionTiletoken punctuation](o](( nl](keytoken punctuation](:token punctuation]( n](PageStorageKeytoken operator](o](token punctuation]((token punctuation](n](roottoken punctuation](o](token punctuation]()token punctuation](,token punctuation]( nl](titletoken punctuation](:token punctuation]( token function](n](Texttoken punctuation](o]((n](roottoken punctuation](o](.na](titletoken punctuation](o](token punctuation]()token punctuation](,token punctuation]( nl](childrentoken punctuation](:token punctuation]( n](roottoken punctuation](o](.na](childrentoken punctuation](o](.token function](na](maptoken punctuation](o]((n](_buildTilestoken punctuation](o](token punctuation]()token punctuation](.token punctuation](token function](na](toListtoken punctuation](o](token punctuation]((token punctuation]()token punctuation](,token punctuation]( token punctuation](o](token punctuation]()token punctuation](;token punctuation]( token punctuation](o](}</p> <p>token metadata symbol](nd](@override n](Widget token function](n](buildtoken punctuation](o]((n](BuildContext n](contexttoken punctuation](o]() token punctuation](o]({ token keyword](k](return token function](n](_buildTilestoken punctuation](o]((n](entrytoken punctuation](o](token punctuation]()token punctuation](;token punctuation]( token punctuation](o](} token punctuation](o](}</p> <p>token keyword](kt](void token function](nf](maintoken punctuation](p]((token punctuation](o]() token punctuation](o]({ token function](n](runApptoken punctuation](o]((token function](n](ExpansionTileSampletoken punctuation](o](token punctuation]((token punctuation]()token punctuation]()token punctuation](;token punctuation]( token punctuation](o](}</p> <pre>
See also:
- The “expand/collapse” part of the Material Design specification: https://material.io/guidelines/components/lists-controls.html#lists-controls-types-of-list-controls- The source code in https://github.com/flutter/flutter/blob/master/examples/catalog/lib/expansion_tile_sample.dart. Credits: This article was initially posted in Flutter.io. </pre>