我使用图片插件( image:^ 2.0.4 ),以便可以在图片上写一些内容,然后将其保存为新图片到设备或通过邮件发送。我尝试使用“ new File ” 加载图像,但Flutter出现错误。我询问并搜索,并得到一个提示,我可以使用rootBundle在Flutter中加载图像。我做到了,我得到以下错误。
[错误:topaz / lib / tonic / logging / dart_error.cc(16)]未处理的异常:无法加载资产:包/ myAppName /资产/图像/ReceiptRaw_1.jpg
当我创建一个简单的Dart控制台应用程序时,该插件可以工作,但无法使用Flutter加载。任何帮助,
这是Flutter代码:
Future<bool> makeReceiptImage() async { // UPDATE **************************************** // load the receipt jpeg var imageData = await rootBundle.load('packages/myAppName/dekonts/ReceiptRaw_1.jpg'); print("imageData: $imageData"); // Prints as imageData: Instance of '_ByteDataView' // UPDATE **************************************** Image _receiptImage = await decodeImage(new File(imageData).readAsBytesSync()); drawString(_receiptImage, arial_48, 440, 30, “Customer Name”, color: 0xFF000000); // Write it to disk as a different jpeg var new_jpeg = await encodeJpg(_receiptImage); String newImagePath = await rootBundle.loadString('packages/myAppName/assets/images/ReceiptRaw_2.jpg'); await new File(‘$newImagePath’).writeAsBytesSync(new_jpeg); }
这是Dart控制台代码:
import 'dart:io'; import 'dart:convert'; import 'dart:async'; import 'package:image/image.dart'; void main() async { // load the receipt jpeg String mImagePath = 'images/ReceiptRaw_1.jpg'; Image _receiptImage = decodeImage(new File(mImagePath).readAsBytesSync()); drawString(_receiptImage, arial_48, 440, 30, “Customer Name”, color: 0xFF000000); // Write it to disk as a different jpeg var new_jpeg = encodeJpg(_receiptImage); new File('images/ReceiptRaw_1.jpg').writeAsBytesSync(new_jpeg); }
更新1: 当我使用下面的代码时,我会得到以下错误:
在pubspec.yaml中检测到错误: 找不到资产的文件或变体:包/ myAppName /资产/图像/ReceiptRaw_1.jpg
String imageData = await rootBundle.loadString('packages/myAppName/assets/images/ReceiptRaw_1.jpg'); Image _receiptImage = await decodeImage(new File(imageData).readAsBytesSync());
更新2: 如果我使用rootBundle.load我得到以下错误。
rootBundle.load
错误:无法将类型为’dart.typed_data :: ByteData’的值分配给类型为’dart.core :: String’的变量。
var imageData = await rootBundle.load('packages/myAppName/assets/images/ReceiptRaw_1.jpg'); Image _receiptImage = await decodeImage(new File(imageData).readAsBytesSync());
新更新:
步骤1: 移动到ReceiptRaw_1.jpg入lib/dekonts/夹
ReceiptRaw_1.jpg
lib/dekonts/
改成:
assets: - packages/myAppName/dekonts/ReceiptRaw_1.jpg
var imageData = await rootBundle.load('packages/myAppName/dekonts/ReceiptRaw_1.jpg'); print("imageData: $imageData");
结果: 打印为
imageData:“ _ ByteDataView”的实例
步骤2: 移至资料 /lib/assets/images/ReceiptRaw_1.jpg夹
/lib/assets/images/ReceiptRaw_1.jpg
assets: - packages/myAppName/lib/assets/images/ReceiptRaw_1.jpg
var imageData = await rootBundle.load('packages/myAppName/lib/assets/images/ReceiptRaw_1.jpg'); print("imageData: $imageData");
结果: 错误为:
解决依赖项…正在运行’gradlew assembleDebug’…在pubspec.yaml中检测到错误:找不到资产的文件或变体:包/myAppName/lib/assets/images/ReceiptRaw_1.jpg
更新:
///要包含第一张图片,pubspec.yaml应用的图片应 ///在资源部分中指定: /// ///资源:///-包/fancy_backgrounds/backgrounds/background1.png /// /// lib/ 是隐含的,因此不应将其包含在资产路径中。
pubspec.yaml
lib/
pub依赖项的文件不能作为文件使用。它们包含在存档文件中。
将图像添加到资产 pubspec.yaml
flutter: assets: - packages/myAppName/assets/images/ReceiptRaw_1.jpg
然后加载
var imageData = await rootBundle.load('packages/myAppName/assets/images/ReceiptRaw_1.jpg');
为此,ReceiptRaw_1.jpg需要将文件放入
myAppName/lib/assets/images/ReceiptRaw_1.jpg
如果该lib/部分是强制性的。