问题描述
我正在合并几张图像并将其显示为一张。 我有两个dart文件，一个用于添加图像，另一个用于显示合并结果。
class SingleImageUpload extends StatefulWidget {
@override
_SingleImageUploadState createState() {
return _SingleImageUploadState();
}
}
class _SingleImageUploadState extends State<SingleImageUpload> {
List<Object> images = List<Object>();
File _selectedFile;
bool _inProcess = false;
Map data = {};
Readerservice _readerservice;
@override
void initState() {
// Todo: implement initState
super.initState();
setState(() {
images.add("Add Image");
images.add("Add Image");
images.add("Add Image");
images.add("Add Image");
});
}
@override
Widget build(BuildContext context) {
return new MaterialApp(
debugShowCheckedModeBanner: false,home: new Scaffold(
appBar: AppBar(
backgroundColor: Colors.white,leading: Padding(
padding: EdgeInsets.only(left: 12),child: IconButton(
icon: Icon(Icons.arrow_back_ios,color: Colors.black,size: 30,),onpressed: () {
Navigator.pushNamed(context,'/');
},title: Row(
mainAxisAlignment: MainAxisAlignment.center,children:<Widget>[
Text('Basic AppBar'),]
),actions: <Widget>[
IconButton(
icon: Icon(Icons.more_vert,onpressed: () {
print('Click start');
},],body:
Column(
children: <Widget>[
SizedBox(height: 10),Row(children: <Widget>[
Text('Image',style: TextStyle(
color: Colors.black,fontSize: 33,fontWeight: FontWeight.bold,)),Text('Merger',style: TextStyle(
color: Colors.orange,]),SizedBox(height: 40),Text(' merge it here'),SizedBox(height: 10),Expanded(
child: buildGridView(),RaisedButton(
textColor: Colors.white,color: Colors.orange,child: Text("Finish",style: TextStyle(fontSize: 15),onpressed: () {
pasimage();
},shape: new RoundedRectangleBorder(
borderRadius: new BorderRadius.circular(8.0),);
}
Widget buildGridView() {
return GridView.count(
shrinkWrap: true,crossAxisCount: 3,childAspectRatio: 1,children: List.generate(images.length,(index) {
if (images[index] is ImageUploadModel) {
ImageUploadModel uploadModel = images[index];
return Card(
clipBehavior: Clip.antiAlias,child: Stack(
children: <Widget>[
Image.file(
uploadModel.imageFile,width: 300,height: 300,Positioned(
right: 5,top: 5,child: InkWell(
child: Icon(
Icons.remove_circle,size: 20,color: Colors.red,onTap: () {
setState(() {
images.replaceRange(index,index + 1,['Add Image']);
});
},);
} else {
return Card(
child: IconButton(
icon: Icon(Icons.add),onpressed: () {
//popup
showDialog(
context: context,builder: (context) {
return Dialog(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(10)),elevation: 16,child: Container(
height: 180.0,width: 330.0,child: ListView(
children: <Widget>[
SizedBox(height: 20),//Center(
Padding(
padding: const EdgeInsets.only(left: 15.0),child: Text(
"Add a Receipt",textAlign: TextAlign.left,style: TextStyle(
fontSize: 24,fontWeight: FontWeight.bold),// ),SizedBox(height: 20),FlatButton(
child: Text(
'Take a photo..',style: TextStyle(fontSize: 20),onpressed: () {
_onAddImageClick(index,ImageSource.camera);
Navigator.of(context).pop();
// picker.getimage(ImageSource.camera);
},textColor: Colors.black,FlatButton(
child: Text(
'Choose from Library..',ImageSource.gallery);
Navigator.of(context).pop();
},);
},);
//pop ends
},);
}
}),);
}
Future _onAddImageClick(int index,ImageSource source ) async {
setState(() {
_inProcess = true;
});
File image = await ImagePicker.pickImage(source: source);
if(image != null){
File cropped = await ImageCropper.cropImage(
sourcePath: image.path,maxWidth: 1080,maxHeight: 1080,compressFormat: ImageCompressFormat.jpg,androidUiSettings: AndroidUiSettings(
toolbarColor: Colors.black,toolbarWidgetColor: Colors.white,//toolbarTitle: "RPS Cropper",statusBarColor: Colors.deepOrange.shade900,backgroundColor: Colors.black,initAspectRatio: CropAspectRatioPreset.original,lockAspectRatio: false
),iosUiSettings: IOSUiSettings(
minimumAspectRatio: 1.0,)
);
this.setState((){
_selectedFile = cropped ;
_inProcess = false;
});
} else {
this.setState((){
_inProcess = false;
});
}
getFileImage(index);
}
void getFileImage(int index) async {
// var dir = await path_provider.getTemporaryDirectory();
setState(() {
ImageUploadModel imageUpload = new ImageUploadModel();
imageUpload.isuploaded = false;
imageUpload.uploading = false;
imageUpload.imageFile = _selectedFile;
imageUpload.imageUrl = '';
images.replaceRange(index,[imageUpload]);
});
}
void pasimage(){
Navigator.pushReplacementNamed(context,'/crop',arguments: {
'imageList':ImagesMerge(
images,///required,images list
direction: Axis.vertical,///direction
backgroundColor: Colors.black26,///background color
fit: false,///scale image to fit others
),});
}
}
class ImageUploadModel {
bool isuploaded;
bool uploading;
File imageFile;
String imageUrl;
ImageUploadModel({
this.isuploaded,this.uploading,this.imageFile,this.imageUrl,});
}
添加图像后点击完成按钮时，显示错误 在处理手势时引发了以下_TypeError： 类型“列表”不是类型“列表”的子类型
请问是否有人知道为什么会出错并帮助我。
解决方法
将images更改为List<Object> images = []。