Dart 如何在Flatter中将图像转换为base64图像?
实际上,我正在尝试将颤振中的Dart 如何在Flatter中将图像转换为base64图像?,dart,flutter,Dart,Flutter,实际上,我正在尝试将颤振中的ImagePicker拾取的图像转换为base64图像。我总是犯错误 FileSystemException: Cannot open file, path = 'file:///storage/emulated/0/Download/Abid_Wipro_neemuchwala1- 770x433.jpg' (OS Error: No such file or directory, errno = 2) E/flutter ( 5042): #0 _F
ImagePicker
拾取的图像转换为base64
图像。我总是犯错误
FileSystemException: Cannot open file, path =
'file:///storage/emulated/0/Download/Abid_Wipro_neemuchwala1-
770x433.jpg' (OS Error: No such file or directory, errno = 2)
E/flutter ( 5042): #0 _File.throwIfError
(dart:io/file_impl.dart:628)
E/flutter ( 5042): #1 _File.openSync
(dart:io/file_impl.dart:472)
E/flutter ( 5042): #2 _File.readAsBytesSync
(dart:io/file_impl.dart:532)
我使用的代码就是这个
File fileData;
/////////////...........
new Container(
child: new FutureBuilder<File>(
future: imageFile,
builder: (BuildContext context, AsyncSnapshot<File> snapshot) {
if (snapshot.connectionState == ConnectionState.done &&
snapshot.data != null) {
fileData = snapshot.data;
return new Container(
height: MediaQuery.of(context).size.height / 2,
width: MediaQuery.of(context).size.width,
margin: const EdgeInsets.all(4.0),
decoration: new BoxDecoration(
image: new DecorationImage(
image: new FileImage(snapshot.data,),
fit: BoxFit.cover
),
),
);
} else if (snapshot.error != null) {
return new Column(children: <Widget>[
centerWidget('Choose Image or Audio or Video'),
_circleAvatar()
]);
} else {
return new Column(children: <Widget>[
centerWidget('Choose Image or Audio or Video'),
_circleAvatar()
]);
}
},
),
),
/////////////////
File imageFile = new File(widget.fileData.uri.toString());
List<int> imageBytes = imageFile.readAsBytesSync();
String base64Image = base64Encode(imageBytes);
文件文件数据;
/////////////...........
新容器(
孩子:新未来建设者(
未来:图像文件,
生成器:(BuildContext上下文,异步快照){
如果(snapshot.connectionState==connectionState.done&&
snapshot.data!=null){
fileData=snapshot.data;
退回新货柜(
高度:MediaQuery.of(context).size.height/2,
宽度:MediaQuery.of(context).size.width,
边距:所有常数边集(4.0),
装饰:新盒子装饰(
图片:新装饰图片(
映像:新文件映像(snapshot.data,),
适合:BoxFit.cover
),
),
);
}else if(snapshot.error!=null){
返回新列(子项:[
centerWidget(“选择图像、音频或视频”),
_圆变星()
]);
}否则{
返回新列(子项:[
centerWidget(“选择图像、音频或视频”),
_圆变星()
]);
}
},
),
),
/////////////////
File imageFile=新文件(widget.fileData.uri.toString());
List imageBytes=imageFile.readAsBytesSync();
字符串base64Image=base64Encode(imageBytes);
请问,有人能告诉我哪里出了错吗
非常感谢,,
Mahi嗨,我刚刚更改了代码,如下所示
List<int> imageBytes = widget.fileData.readAsBytesSync();
print(imageBytes);
String base64Image = base64Encode(imageBytes);
List imageBytes=widget.fileData.readAsBytesSync();
打印(图像字节);
字符串base64Image=base64Encode(imageBytes);
现在这一切都很好
最好异步读取,因为映像可能非常大,这可能会导致主线程阻塞
List<int> imageBytes = await widget.fileData.readAsBytes();
List imageBytes=wait widget.fileData.readAsBytes();
您只需将图像更改为字符串:
final bytes=Io.File(imageBytes.path).readAsBytesSync();
字符串img64=base64Encode(字节);
容器(
儿童:新的手势检测器(
onTap:()异步{
聚焦范围(上下文)
.requestFocus(新的FocusNode());
等待getImage();
},
孩子:新中心(
子项:_image==null
?新堆栈(
儿童:[
新中心(
孩子:新CircleAvatar(
半径:80.0,
背景颜色:
常量颜色(0xFF778899),
),
),
新中心(
子:图标(
Icons.perm_标识,
尺寸:120,
),
),
],
)
:新CircleAvatar(
半径:60,
孩子:斜坡(
子对象:对齐(
高度系数:0.8,
宽度系数:1.0,
子项:新的Image.file(_Image),
),
),
),
),
),
),
Future getImage()异步{
UserService userRestSrv=UserService();
PickedFile image=await ImagePicker().getImage(来源:ImageSource.gallery,imageQuality:50);
如果(图像!=null){
设置状态(){
_image=文件(image.path);
});
final bytes=文件(image.path).readAsBytesSync();
字符串img64=base64Encode(字节);
var responseProfileImage=await userRestSrv.updateImage(userId,img64);
if(responseProfileImage!=null&&responseProfileImage.data['ResponseCode']=“00”)
showMessage('Profile Image not upload',false);
}
}
您尝试读取的文件不存在或应用程序没有读取权限。这个错误似乎与base64Thanks@GünterZöchbauer,但文件存在于指定的路径中,和显示在手机上,但无法将图像转换为base64当错误显示该文件无法读取时,它仍然与base64无关。嗨@zoechi是否有其他解决方案,以便我可以将图像文件转换为base64编码。谢谢@zoechi,你很惊讶路径被修改,我删除了行fileimagefile=newfile(widget.fileData.uri.toString())
并将我的代码更改为List imageBytes=widget.fileData.uri.readAsBytesSync()代码>现在正在运行。您从哪里获得函数base64Encode()
?hi@ArnoldParge它来自dart:convert
API,如果您想查看它的话。
Container(
child: new GestureDetector(
onTap: () async {
FocusScope.of(context)
.requestFocus(new FocusNode());
await getImage();
},
child: new Center(
child: _image == null
? new Stack(
children: <Widget>[
new Center(
child: new CircleAvatar(
radius: 80.0,
backgroundColor:
const Color(0xFF778899),
),
),
new Center(
child: Icon(
Icons.perm_identity,
size: 120,
),
),
],
)
: new CircleAvatar(
radius: 60,
child: ClipOval(
child: Align(
heightFactor: 0.8,
widthFactor: 1.0,
child: new Image.file(_image),
),
),
),
),
),
),
Future getImage() async {
UserService userRestSrv = UserService();
PickedFile image = await ImagePicker().getImage(source: ImageSource.gallery, imageQuality: 50);
if (image != null) {
setState(() {
_image = File(image.path);
});
final bytes = File(image.path).readAsBytesSync();
String img64 = base64Encode(bytes);
var responseProfileImage = await userRestSrv.updateImage(userId, img64);
if (responseProfileImage != null && responseProfileImage.data['ResponseCode'] == "00")
showMessage('Profile Image not uploaded', false);
}
}