Flutter开发08-自定义组件

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Flutter开发

提示框

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import 'package:flutter/material.dart';
import 'dart:async';

class ToastHelper {
  static void showToast(BuildContext context, String text) {
    const style = TextStyle(color: Colors.white, fontSize: 16.0);

    Widget widget = Center(
      child: Material(
        child: Container(
          padding: const EdgeInsets.symmetric(vertical: 10.0, horizontal: 10.0),
          decoration: BoxDecoration(
              color: Colors.black.withOpacity(0.5),
              borderRadius: BorderRadius.all(Radius.circular(6))),
          child: Text(
            text,
            textAlign: TextAlign.center,
            style: style,
          ),
        ),
      ),
    );
    var entry = OverlayEntry(
      builder: (_) => widget,
    );

    Overlay.of(context).insert(entry);

    Timer(const Duration(seconds: 2), () {
      entry?.remove();
    });
  }
}

调用

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ToastHelper.showToast(context, "双击两次退出！");

加载中

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import 'package:flutter/material.dart';

class LoadingHelper {
  static bool isShow = false;

  static void showLoading(BuildContext context, {String text}) {
    showDialog(
        context: context,
        barrierDismissible: false,
        builder: (_) {
          if (text != null) {
            return new ZLoadingDialog(
              outsideDismiss: false,
              loadingText: text,
            );
          } else {
            return new ZLoadingDialog(
              outsideDismiss: false,
            );
          }
        });
    isShow = true;
  }

  static void hideLoading(BuildContext context) {
    if (isShow) {
      Navigator.of(context).pop();
      isShow = false;
    }
  }
}

class ZLoadingDialog extends StatefulWidget {
  String loadingText;
  bool outsideDismiss;
  Function dismissCallback;

  ZLoadingDialog(
      {Key key,
      this.loadingText = "加载中...",
      this.outsideDismiss = true,
      this.dismissCallback})
      : super(key: key);

  @override
  State<ZLoadingDialog> createState() => _LoadingDialog();
}

class _LoadingDialog extends State<ZLoadingDialog> {
  _dismissDialog() {
    if (widget.dismissCallback != null) {
      widget.dismissCallback();
    }
    Navigator.of(context).pop();
  }

  @override
  void initState() {
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return new GestureDetector(
      onTap: widget.outsideDismiss ? _dismissDialog : null,
      child: Material(
        type: MaterialType.transparency,
        child: new Center(
          child: new SizedBox(
            width: 120.0,
            height: 120.0,
            child: new Container(
              decoration: ShapeDecoration(
                color: Color(0xffffffff),
                shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.all(
                    Radius.circular(8.0),
                  ),
                ),
              ),
              child: new Column(
                mainAxisAlignment: MainAxisAlignment.center,
                crossAxisAlignment: CrossAxisAlignment.center,
                children: <Widget>[
                  new CircularProgressIndicator(),
                  new Padding(
                    padding: const EdgeInsets.only(
                      top: 20.0,
                    ),
                    child: new Text(
                      widget.loadingText,
                      style: new TextStyle(fontSize: 12.0),
                    ),
                  ),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}

调用方式

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LoadingHelper.showLoading(context);
client
    .teacher_login(this.username, this.userpwd)
    .then((value) => {login(value)})
    .catchError((err) =>
        {ToastHelper.showToast(context, "请求失败！")})
    .whenComplete(
        () => LoadingHelper.hideLoading(context));