将Base64字符串解码为图像在Flutter中

huangapple
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英文:

DECODE BASE64STRING TO IMAGE IN FLUTTER

问题

这是我的代码来显示图片，但最终出现了以下错误：
I/flutter (15439): 格式异常：无效的长度，必须是四的倍数（在字符256处）

有人可以帮助我吗？

英文:

this my code to display image

  1. body: ListView.builder(
  2.       itemCount: jsonList == null ? 0 : jsonList.length,
  3.       itemBuilder: (BuildContext context, int index) {
  4.         return ListTile(
  5.           leading:Image(image: MemoryImage(base64Decode(base64String))),
  6.           trailing: Text(jsonList[index]['pname']
  7.             ,
  8.             style: TextStyle(color: Colors.brown, fontSize: 15),
  9.           ),
  10.           title: Text(jsonList[index]['pdesc']),
  11.         );
  12.       }),

but end up with this error
I/flutter (15439): FormatException: Invalid length, must be multiple of four (at character 256)
I/flutter (15439): ...2vt6b997q855/zhVdW9337r3dgewn+fll6e607fqVJ3z/Z3z209deIfeof+fSfytO1CEBCfeR+0
I/flutter (15439):

anybody please help me?

答案1

得分: 0

The base64String is wrong, try another and it should work for you. I'll send you an example.

  1. import 'dart:convert';
  2. import 'package:flutter/material.dart';
  4. void main() => runApp(const MyApp());
  6. class MyApp extends StatelessWidget {
  7.   const MyApp({super.key});
  9.   @override
  10.   Widget build(BuildContext context) {
  11.     final List jsonList = [
  12.       {"pname": "test", "pdesc": "example"}
  13.     ];
  15.     //String base64String =
  16.     //    "iVBORw0KGgoAAAANSUhEUgAAAGAAAABgCAYAAADimHc4AAAABHNCSVQICAgIfAhkiAAAIABJREFUeJztnXmYHVWd9z/nVN2lt3R30p3urIQkhCSQEMISdjCIEEZREYbNDcdxXubl9cGRxdFBZdwQlRl1RHnAEXVEUV9FUXYxISQhZCH7TrbO2vt6b997q855/zhVdW9337r3dgewn+fll6e607fqVJ3z/Z3z209deIfeof+fSfytO1CEBCfeR+0";
  17.     String base64String =
  18.         "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";
  19.     return MaterialApp(
  20.       title: 'Material App',
  21.       home: Scaffold(
  22.         appBar: AppBar(
  23.           title: const Text('Material App Bar'),
  24.         ),
  25.         body: ListView.builder(
  26.             itemCount: jsonList.length,
  27.             itemBuilder: (BuildContext context, int index) {
  28.               return ListTile(
  29.                 leading: Image(image: MemoryImage(base64Decode(base64String))),
  30.                 trailing: Text(
  31.                   jsonList[index]['pname'],
  32.                   style: const TextStyle(color: Colors.brown, fontSize: 15),
  33.                 ),
  34.                 title: Text(jsonList[index]['pdesc']),
  35.               );
  36.             }),
  37.       ),
  38.     );
  39.   }
  40. }
英文:

The base64String is wrong, try another and it should work for you. I'll send you an example.

  1. import 'dart:convert';
  2. import 'package:flutter/material.dart';
  4. void main() => runApp(const MyApp());
  6. class MyApp extends StatelessWidget {
  7.   const MyApp({super.key});
  9.   @override
  10.   Widget build(BuildContext context) {
  11.     final List jsonList = [
  12.       {"pname": "test", "pdesc": "example"}
  13.     ];
  15.     //String base64String =
  16.     //    "iVBORw0KGgoAAAANSUhEUgAAAGAAAABgCAYAAADimHc4AAAABHNCSVQICAgIfAhkiAAAIABJREFUeJztnXmYHVWd9z/nVN2lt3R30p3urIQkhCSQEMISdjCIEEZREYbNDcdxXubl9cGRxdFBZdwQlRl1RHnAEXVEUV9FUXYxISQhZCH7TrbO2vt6b997q855/zhVdW9337r3dgewn+fll6e607fqVJ3z/Z3z209deIfeof+fSfytO1CEBCfeR+0";
  17.     String base64String =
  18.         "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";
  19.     return MaterialApp(
  20.       title: 'Material App',
  21.       home: Scaffold(
  22.         appBar: AppBar(
  23.           title: const Text('Material App Bar'),
  24.         ),
  25.         body: ListView.builder(
  26.             itemCount: jsonList.length,
  27.             itemBuilder: (BuildContext context, int index) {
  28.               return ListTile(
  29.                 leading: Image(image: MemoryImage(base64Decode(base64String))),
  30.                 trailing: Text(
  31.                   jsonList[index]['pname'],
  32.                   style: const TextStyle(color: Colors.brown, fontSize: 15),
  33.                 ),
  34.                 title: Text(jsonList[index]['pdesc']),
  35.               );
  36.             }),
  37.       ),
  38.     );
  39.   }
  40. }

huangapple
  • 本文由 发表于 2023年7月20日 22:40:29
  • 转载请务必保留本文链接：https://go.coder-hub.com/76731023.html
  • base64
  • flutter
  • listview
  • node.js
  • uint8list
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