Question

我正在尝试的是在没有TextEditingController的情况下复制“ setText”。由于使用的是FutureBuilder，因此无法手动更新状态，因此无法选择TextEditingController。

下面是更好理解的代码。

class DynamicFormBuilder {
  GlobalKey<FormBuilderState> dynamicFormKey = GlobalKey<FormBuilderState>();

  String getVariableData(String variable) {
    return dynamicFormKey.currentState.fields[variable].currentState.value;
  }

  void setVariableData(String variable, String value) {
    dynamicFormKey.currentState.fields[variable].currentState.didChange(value);
  }

  Widget workOnWidget(DynamicFormResponse widget) {
    switch (widget.widget) {
      case "text":
        return Text(
          widget.displayText,
          style: TextStyle(
              fontWeight: widget.style.fontWeight == "bold"
                  ? FontWeight.bold
                  : FontWeight.normal,
              fontSize: double.parse(widget.style.fontSize)),
        );
      case "editable":
        return FormBuilderTextField(
          attribute: widget.variable,
          decoration: InputDecoration(labelText: widget.displayText),
          onChanged: (val) {
            if (widget.onChanged != null) {
              onChangedFunctionMapper[widget.variable](val);
            }
          },
        );
      case "datepicker":
        return FormBuilderDateTimePicker(
          attribute: widget.variable,
          inputType: InputType.date,
          format: DateFormat("dd/MM/yyyy"),
          decoration: InputDecoration(labelText: widget.displayText),
          validators: [
            FormBuilderValidators.required(),
          ],
        );
      case "divider":
        return Container(
          margin: EdgeInsets.fromLTRB(5, 10, 5, 10),
          width: double.infinity,
          height: 10,
          color: accentColor,
        );
      case "dropdown":
        return FormBuilderDropdown(
          attribute: widget.variable,
          items: convertDropdown(widget.options),
          hint: Text(widget.hint),
          decoration: InputDecoration(labelText: widget.displayText),
        );
      case "radioButton":
        return FormBuilderRadioButton(
          displayText: widget.displayText,
          attribute: widget.variable,
          isHorizontal: widget.isHorizontal,
          onChanged: (val) {
            if (val == "yes") {
              visibilityMap["age"] = true;
            } else {
              visibilityMap["age"] = false;
            }
          },
          options: widget.options
              .map((lang) => FormBuilderFieldOption(value: lang))
              .toList(growable: false),
        );
      default:
        return Text("lol");
    }
  }

  Widget buildForms(BuildContext context, Future<dynamic> fetchJSON) {
    jsonData = new List();
    dynamicFormKey = GlobalKey<FormBuilderState>();
    accentColor = Theme.of(context).accentColor;
    return FutureBuilder(
      builder: (context, snapshot) {
        if (snapshot.connectionState == ConnectionState.none &&
            snapshot.hasData == null) {
          return Container(
            child: Text("No Data got loaded"),
          );
        } else if (snapshot.connectionState == ConnectionState.done) {
          for (int i = 0; i < snapshot.data.length; i++) {
            jsonData.add(DynamicFormResponse.fromJson(snapshot.data[i]));
          }
          return ListView(
            padding: EdgeInsets.all(10),
            children: <Widget>[
              FormBuilder(
                key: dynamicFormKey,
                autovalidate: false,
                child: Card(
                  child: Padding(
                    padding: const EdgeInsets.all(10),
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: jsonData.map<Widget>((widget) {
                        print(widget.widget);
                        return workOnWidget(widget);
                      }).toList(),
                    ),
                  ),
                ),
              ),
            ],
          );
        } else {
          return Center(
            child: CircularProgressIndicator(),
          );
        }
      },
      future: fetchJSON,
    );
  }
}

所以在这里，当我使用setVariableData（variable，data）进行更新时，处于状态的变量正在更新，而TextFields中没有反映同样的状态。

Answer 1

首先，您的问题很令人困惑。但是，我想，您正在寻找一种在提交数据时将值设置为某些xyz变量的方法，对吗？

您可以通过两种方式执行此操作，这些方式是：

使用onSubmitted Property：当用户在文本字段中完成值的编辑后，将给出值

使用TextEditingController：控制要编辑的文本。

使用TextEditingController的代码：

TextEditingController _controller = new TextEditingController();

TextField(
  controller: _controller 
)

//suppose you have a button which will print the data of the textfield for on onPressed
RaisedButton(
 onPressed: () {
    //this will print the value you've entered into the textfield
    print(this._controller.text)
    //change the value using setState here
    setState((){
        value_to_be_changed_variable = this._controller.text
    })
 },
 child: const Text('Submit', style: TextStyle(fontSize: 20))
)

使用onSubmitted属性的代码：

TextField(
  onSubmitted: (value) {
     //do the operation here with the help of setState()
     setState((){
        variable_value_to_be_changed = value
     })
  }
)

我希望这足以满足您的需求。有关更多信息，请彻底了解Textfield Flutter Class。它将在很多方面为您提供帮助

如何使用全局键设置文本字段值

1 个答案: