my.previewImage

//.json
{
    "defaultTitle": "Picture"
}

<!-- .axml -->
<view class="page">
  <view class="page-section">
    <view class="page-section-btns">
      <view onTap="chooseImage">Select image</view>
      <view onTap="previewImage">Preview image</view>
      <view onTap="saveImage">Save image</view>
    </view>
  </view>
</view>

//.js
Page({
  chooseImage() {
    my.chooseImage({
      sourceType: ['camera','album'],
      count: 2,
      success: (res) => {
        my.alert({
          content: JSON.stringify(res),
          
        });
      },
      fail:()=>{
        my.showToast({
          content: 'fail', // text contents 
        });
      }
    })
  },
  previewImage() {
    my.previewImage({
      current: 2,
      urls: [
        'https://img.example.com/example1.jpg',
        'https://img.example.com/example2.jpg',
        'https://img.example.com/example3.jpg'
      ],
    });
  },
  saveImage() {
    my.saveImage({
      url: 'https://img.example.com/example1.jpg',
      showActionSheet: true,
      success: () => {
        my.alert({
          title: 'Save success',
        });
      },
    });
  }
});