Question

我正在使用此插件：https://github.com/blinkmobile/cordova-plugin-sketch与Ionic 3。

我的最后一个重要步骤是将结果放在回调函数之外，以便进一步使用它。

这是我的代码：

anhangArray: Array<{ name: string, value: string }>=[];



  takePhoto() {
  const options: CameraOptions = {
  quality: 100,
  destinationType: this.camera.DestinationType.FILE_URI,
  encodingType: this.camera.EncodingType.JPEG,
  mediaType: this.camera.MediaType.PICTURE,
  correctOrientation: true,
  allowEdit: false,
}

this.camera.getPicture(options).then((imageData) => {

  // imageData is either a base64 encoded string or a file URI
  // If it's base64:
  //base64Image = 'data:image/jpeg;base64,' + imageData;
  //>>> FILE_URI
  this.getSketch(imageData);

}, (err) => {
  // Handle error
});
}

getSketch(src: string) {
window.navigator.sketch.getSketch(this.onSuccess, this.onFail, {
  destinationType: window.navigator.sketch.DestinationType.DATA_URL,
  encodingType: window.navigator.sketch.EncodingType.JPEG,
  inputType: window.navigator.sketch.InputType.FILE_URI,
  inputData: src
});
}

onSuccess(imageData) {
var _mythis = this;
if (imageData == null) { return; }

// do your thing here!
setTimeout(function () {
  if (imageData.indexOf("data:image") >= 0) {
  } else {
    imageData = "data:image/jpeg;base64," + imageData;
  }
  _mythis.anhangArray.push({ name: "anhang_" + parseInt(_mythis.user._kunnr), value: imageData });
  console.log(this.anhang);

}, 0);
}

错误：未捕获的TypeError：无法读取未定义的属性'anhangArray'

Answer 1

您的问题在于 window.navigator.sketch.getSketch（）。当 window.navigator.sketch.getSketch 触发您的回调 this.onSuccess 时，会更改回调的范围。要解决此问题，您可以更改下面的实现。

getSketch(src: string) {
  window.navigator.sketch.getSketch(imageData => {
    this.onSuccess(imageData);
  }, error => {
    this.onFail(error);
  }, {
    destinationType: window.navigator.sketch.DestinationType.DATA_URL,
    encodingType: window.navigator.sketch.EncodingType.JPEG,
    inputType: window.navigator.sketch.InputType.FILE_URI,
    inputData: src
  });
}

Answer 2

你也可以这样解决：

＆＃13;

this.camera.getPicture(options).then((imageData) => {

  // imageData is either a base64 encoded string or a file URI
  // If it's base64:
  //base64Image = 'data:image/jpeg;base64,' + imageData;
  //>>> FILE_URI
  this.getSketch(imageData).bind(this);

＆＃13;

其中.bind(this)将范围传递给您的来电者。

访问回调内的类属性

2 个答案: