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Flutter:在FutureBuilder内部导航

flutter-futurebuilder flutter

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Dolly Storey · 技术社区 · 2 年前

如何转到Futurebuilder的下一个屏幕? 基本上,条件是: 如果快照没有数据,[return CircularProgressIndicator()] 否则,如果'keyword'='target',请转到NextScreen, else返回[ListView.builder]

     body: FutureBuilder(
          future: generatedText,
          builder: (BuildContext context, AsyncSnapshot snapshot) {
            if (snapshot.data == null) {
              return const CircularProgressIndicator();
            } else if (widget.keyword == 'target') {
              // Go to NextScreen instead of 'ListView.builder'
              Navigator.push(context, MaterialPageRoute(builder: (context) => NextScreen(text: snapshot.data[7]), ),
              );
            } else {
              return ListView.builder(
                itemCount: snapshot.data.length,
                itemBuilder: (BuildContext context, int index) {
                  return InkWell(onTap: () {
                      Navigator.push(context, MaterialPageRoute(builder: (context) => NextScreen(text: snapshot.data[index]),),
                      );
                    },
                    child: Text(snapshot.data[index],
                    ),
                  ); },
              );
            }  },  ),

1 回复 | 直到 2 年前

1

Adhnan Eriyadan 2 年前

要计划在当前帧完成渲染后在后续帧上执行的回调,请使用 小工具Binding.instance.addPostFrameCallback Flutter上下文中的帧是应用程序的整个渲染周期,在此期间,框架通过计算布局、绘制小部件和执行其他操作来更新用户界面。

body: FutureBuilder(
  future: generatedText,
  builder: (BuildContext context, AsyncSnapshot snapshot) {
    if (snapshot.connectionState == ConnectionState.waiting) {
      // Show a loading indicator while waiting for the data
      return CircularProgressIndicator();
    } else if (snapshot.hasError) {
      // Handle error state
      return Text('Error: ${snapshot.error}');
    } else if (widget.keyword == 'target') {
      // Use Navigator.pushReplacement to go to NextScreen instead of 'ListView.builder'
      WidgetsBinding.instance.addPostFrameCallback((_) {
        Navigator.pushReplacement(
          context,
          MaterialPageRoute(
            builder: (context) => NextScreen(text: snapshot.data[7]),
          ),
        );
      });
      return Container(); // Return an empty container while navigating
    } else {
      return ListView.builder(
        itemCount: snapshot.data.length,
        itemBuilder: (BuildContext context, int index) {
          return InkWell(
            onTap: () {
              Navigator.push(
                context,
                MaterialPageRoute(
                  builder: (context) => NextScreen(text: snapshot.data[index]),
                ),
              );
            },
            child: Text(snapshot.data[index]),
          );
        },
      );
    }
  },
),

试试这个代码,让我知道