1.首先在pubspec.yaml文件中新增依赖pub.dev

image_picker: ^0.8.7+5
image_cropper: ^4.0.1

2.在Android的AndroidManifest.xml文件里面添加权限

<activityandroid:name="com.yalantis.ucrop.UCropActivity"android:screenOrientation="portrait"android:theme="@style/Theme.AppCompat.Light.NoActionBar"/>

3.在ios的Info.plist文件里面添加权限 项目根目录

    <key>NSCameraUsageDescription</key><string>这是你的自拍照</string><key>NSMicrophoneUsageDescription</key><string>用于音频插件</string><key>NSPhotoLibraryUsageDescription</key><string>用于相册选择插件</string><key>UIBackgroundModes</key><array><string>remote-notification</string></array>

4.代码实现

​​​​​​​_checkAvatar() {if (!kIsWeb) {loading(() async {final picker = ImagePicker();final pickerFile = await picker.pickImage(source: ImageSource.gallery);if (pickerFile != null) {CroppedFile? croppedImage = await ImageCropper().cropImage(sourcePath: pickerFile.path, //图片资源aspectRatio: const CropAspectRatio(ratioX: 1, ratioY: 1), //裁剪框比例uiSettings: [AndroidUiSettings(toolbarTitle: '裁剪',lockAspectRatio: true //锁定图片纵横比),IOSUiSettings(title: '裁剪',resetButtonHidden: true, //不显示重置按钮aspectRatioLockEnabled: true, //锁定图片纵横比aspectRatioPickerButtonHidden: true, //隐藏切换纵横比按钮doneButtonTitle: "完成", //confirm按钮文字cancelButtonTitle: "取消" //cancel按钮文字)]);//根据XFile对象的路径获得图片进行裁剪//裁剪完成if(croppedImage != null) {//裁剪后图片的路径String filepath = croppedImage.path;final res = await Api.getInstance().uploadAvatar(Provider.memberId, filepath);//pickerFile.pathif (res['code'] == 0) {setState(() {ThemeSnackBar.show(context, res['msg']);_getUserInfo();_user['profilePhoto'] = res['data']['url'];});} else {ThemeSnackBar.show(context, res['msg']);}print("filepath-----$filepath");}}});} else {final uploadInputElement = html.FileUploadInputElement();uploadInputElement.multiple = false;uploadInputElement.draggable = true;uploadInputElement.click();uploadInputElement.onChange.listen((event) {final file = uploadInputElement.files?.first;if (file != null) {loading(() async {final formData = html.FormData();formData.appendBlob("avatarfile", file.slice(), file.name);formData.append("memberId", Provider.memberId);Api.getInstance().uploadAvatarFromHtml(formData, (e) {if (e['code'] == 0) {setState(() {_user['profilePhoto'] = e['data']['url'];});} else {ThemeSnackBar.show(context, e['msg']);}});});}});}