小编Hac*_*ode的帖子

我正在尝试获取某些数组元素的值。它适用于元素 [0]、[1]、[2]、[3]，但不适用于 [4]。

function getBase64() {
  const urls = ['https://i.imgur.com/egNg7JU.jpg',
    'https://i.imgur.com/RLZ7WH1.jpg', 'https://i.imgur.com/qfabBbA.jpg',
    'https://i.imgur.com/Zuh1KaX.jpg', 'https://i.imgur.com/yD7X6Q1.jpg'
  ];

  let base64urls = [];

  const start = async () => {
    await asyncForEach(urls, async (num) => {
      await waitFor(50)
      toDataURL(num, function(dataURL) {
        base64urls.push(dataURL);
      });
    })
    console.log(base64urls);
    console.log(base64urls[4]);
  }
  start()

}

async function asyncForEach(array, callback) {
  for (let index = 0; index < array.length; index++) {
    await callback(array[index], index, array)
  }
}

const waitFor = (ms) => new Promise(r => setTimeout(r, ms))

toDataURL简单地返回图像的 base64 值。每当我尝试 …