SizedBox.shrink()或Container()没有返回空小部件吗？

Question

我使用List.generate()从一个JSON对象中为每个类别创建一个表情符号列表。我有一个搜索栏，用于缩小搜索结果的范围。如果其中一个表情关键字包含搜索栏中的字符，则应该只显示该表情。

问题是SizedBox.shrink()并不像我希望的那样是空的。SizedBox.shrink()不是返回空部件的推荐方法吗？

谢谢!

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          Padding(
            padding: EdgeInsets.only(left: 16, right: 16, top: 8),
            child: ClipRRect(
              borderRadius: BorderRadius.circular(20.0),
              child: Container(
                padding: EdgeInsets.only(left: 12, right: 12),
                color: Colors.grey[200],
                child: TextField(
                  onChanged: (change) {
                    setState(() {
                      searchTarget = change;
                    });
                  },
                  controller: searchController,
                  cursorColor: Colors.black,
                  decoration: InputDecoration(
                      border: InputBorder.none,
                      hintText: "Search for Icon..."),
                ),
              ),
            ),
          ),
          Expanded(
            child: Container(
              padding: EdgeInsets.only(
                top: 16,
                left: 16,
              ),
              child: ListView.builder(
                scrollDirection: Axis.vertical,
                itemCount: this.jsonData.keys.length,
                itemBuilder: (context, index) {
                  return Column(
                    children: [
                      Padding(
                        padding: EdgeInsets.only(
                            bottom: 16, top: (index == 0) ? 0 : 16),
                        child: Align(
                          alignment: Alignment.centerLeft,
                          child: Text(
                            this.jsonData.keys.toList()[index],
                            style: TextStyle(
                                fontSize: 20, fontWeight: FontWeight.bold),
                          ),
                        ),
                      ),
                      GridView.count(
                        shrinkWrap: true,
                        physics: NeverScrollableScrollPhysics(),
                        crossAxisCount: 8,
                        children: List.generate(
                          this.jsonData[this.jsonData.keys.toList()[index]].length, (jndex) {

                          var emoji = this.jsonData[this.jsonData.keys.toList()[index]][jndex];

                          if (this.searchTarget.length > 0 || this.searchTarget != " "){
                            for (int i = 0; i < emoji['keywords'].length; i++){
                              if (emoji['keywords'][i].contains(this.searchTarget)){
                                return Text(
                                emoji['emoji'],
                                style: TextStyle(fontSize: 25),
                                );
                              }
                            }
                          }

                          return SizedBox.shrink();
                        }),
                      ),
                    ],
                  );
                },
              ),
            ),
          ),

Answer 1

我解决了。我没有直接构建网格视图，而是创建了一个自己生成列表的方法。