Question

以下是一些代码：

- (IBAction)buttonClicked:(id)sender
{

    self.alertController = [UIAlertController alertControllerWithTitle: nil
                                                           message: nil
                                                    preferredStyle: UIAlertControllerStyleAlert];

    MyCustomViewController *v     = [[MyCustomViewController alloc] init];

    [self.alertController setValue:v forKey:@"contentViewController"];
    [self presentViewController: self.alertController animated: true  completion: nil];

}

它读入此文件：

import fs = require('fs');

export interface Answer {
  order: number,
  text: string
}

export class Config {
  responses:Answer[];
  timestamp_column: string;
  name_column: string

  fromJSONFile(fileName: string) {
    var fileString = fs.readFileSync(fileName);
    var parsedFile = JSON.parse(fileString.toString());
    this.responses = parsedFile.responses;
    this.timestamp_column = parsedFile.timestamp_column;
    this.name_column = parsedFile.name_column;
  }

  mapAnswerToNum(answer:string):number {
    for (var a of this.responses) {
      if (a.text == answer) { return a.order;}
    }
    throw new Error(`Invalid response string ${answer}`);
  }
}

请注意，我正在从fromJSONFile中逐个复制每个实例变量的相应JSON字段。似乎重复，因为我注意确保类的结构与JSON文件完全相同。还有更好的方法吗？

Answer 1

使用Object.assign

fromJSONFile(fileName: string) {
    var fileString = fs.readFileSync(fileName);
    var parsedFile = JSON.parse(fileString.toString());
    Object.assign(this,parsedFile);
}

加载实例变量在TypeScript中形成一个文件

1 个答案: