Flutter常见问题汇总

Flutter常见问题汇总

目录

1. Mac os 10.15 运行‘idevice_id’无法验证开发者
2. json数据转换
3. TextField键盘显示隐藏
4. 横竖屏设置
5. TextField光标文字焦点不对齐问题
6. ios打包白屏
7. 图片充满父视图
8. 运行报错：Unhandled Exception: ServicesBinding.defaultBinaryMessenger was accessed before the binding was initialized.

解决方案

• 1. Mac os 10.15 运行‘idevice_id’无法验证开发者

     
     1576138438797.jpg

sudo xattr -d com.apple.quarantine [your_path]/flutter/bin/cache/artifacts/libimobiledevice/idevice_id
sudo xattr -d com.apple.quarantine [your_path]/flutter/bin/cache/artifacts/libimobiledevice/ideviceinfo
sudo xattr -d com.apple.quarantine [your_path]/flutter/bin/cache/artifacts/libimobiledevice/idevicesyslog
sudo xattr -d com.apple.quarantine [your_path]/flutter/bin/cache/artifacts/usbmuxd/iproxy

替换为自己的路径

• 2. json数据转换
     json_to_dart

// 使用范例：
var list = json.decode(widget.itemBean.formDefaultValue);
  var items = (list as List).cast().map((value) {
  return Bean.formJson(value);
}).toList();

• 3. TextField键盘显示隐藏

// 显示键盘
focusNode.requestFocus();
// 隐藏键盘
focusNode.unfocus();

• 4. 横竖屏设置

SystemChrome.setPreferredOrientations([
    DeviceOrientation.portraitUp,
    DeviceOrientation.portraitDown
  ]);
runApp(MyApp());

• 5. TextField光标文字焦点不对齐问题

TextField(
   style: TextStyle(textBaseline: TextBaseline.alphabetic),
)

6. ios打包白屏

• 1. 在项目下运行：

flutter build ios --release

• 2. 在Xcode中打开项目， Product -> Archive 即可

7. 图片充满父视图

ConstrainedBox(
        child: Image.asset(
                  AssetImages.start2,
                  fit: BoxFit.cover,
                  ),
        constraints: new BoxConstraints.expand(),
       )

8. 运行报错：Unhandled Exception: ServicesBinding.defaultBinaryMessenger was accessed before the binding was initialized.

void main() {
  // 加上这句即可
  WidgetsFlutterBinding.ensureInitialized();
  //
  runApp(MyApp());
}