lift-app/lib/widgets/load_image.dart

import 'dart:math';

import 'package:cached_network_image/cached_network_image.dart';
import 'package:common_utils/common_utils.dart';
import 'package:flutter/material.dart';
import 'package:liftmanager/utils/image_utils.dart';
import 'package:liftmanager/utils/utils.dart';

/// 图片加载（支持本地与网络图片）
class LoadImage extends StatelessWidget {
  const LoadImage(this.image,
      {Key key,
      this.width,
      this.height,
      this.fit: BoxFit.cover,
      this.format: "png",
      this.holderImg: "none"})
      : super(key: key);

  final String image;
  final double width;
  final double height;
  final BoxFit fit;
  final String format;
  final String holderImg;

  @override
  Widget build(BuildContext context) {
    if (TextUtil.isEmpty(image) || image == "null") {
      return LoadAssetImage(holderImg,
          height: height, width: width, fit: fit, format: format);
    } else {
      if (image.startsWith("http")) {
        return CachedNetworkImage(
          imageUrl: Utils.getImagePath(image),
          placeholder: (context, url) =>
              LoadAssetImage(holderImg, height: height, width: width, fit: fit),
          errorWidget: (context, url, error) =>
              LoadAssetImage(holderImg, height: height, width: width, fit: fit),
          width: width,
          height: height,
          fit: fit,
        );
      } else {
        return LoadAssetImage(image,
            height: height, width: width, fit: fit, format: format);
      }
    }
  }
}

/// 加载本地资源图片
class LoadAssetImage extends StatelessWidget {
  const LoadAssetImage(this.image,
      {Key key,
      this.width: 25,
      this.height: 25,
      this.fit,
      this.format: 'png',
      this.color})
      : super(key: key);

  final String image;
  final double width;
  final double height;
  final BoxFit fit;
  final String format;
  final Color color;

  @override
  Widget build(BuildContext context) {
    return Image.asset(
      ImageUtils.getImgPath(image, format: format),
      height: height,
      width: width,
      fit: fit,
      color: color,
    );
  }
}

/// 加载网络图片，并进行异常处理，对路径进行验证，如果是相对路径，就拼接前缀，如果是绝对路径就直接显示
class LoadNetworkImage extends StatelessWidget {
  const LoadNetworkImage(this.image,
      {Key key,
      this.width,
      this.height,
      this.fit: BoxFit.cover,
      this.isWater = false,
      this.format: "png",
      this.holderImg: "brand_default"})
      : super(key: key);

  final String image;
  final double width;
  final double height;
  final BoxFit fit;
  final String format;
  final String holderImg;
  final bool isWater;

  @override
  Widget build(BuildContext context) {
    if (TextUtil.isEmpty(image) || image == "null") {
      return LoadAssetImage(holderImg,
          height: height, width: width, fit: fit, format: format);
    } else {
      return CachedNetworkImage(
        imageUrl: Utils.getImagePath(image, isWater: isWater),
        placeholder: (context, url) =>
            LoadAssetImage(holderImg, height: height, width: width, fit: fit),
        errorWidget: (context, url, error) =>
            LoadAssetImage(holderImg, height: height, width: width, fit: fit),
        width: width,
        height: height,
        fit: fit,
      );
    }
  }
}

class LoadNetworkImageAlt extends StatelessWidget {
  LoadNetworkImageAlt(
    this.image, {
    Key key,
    this.width,
    this.height,
    this.fit: BoxFit.cover,
    this.isWater = false,
    this.format: "png",
  }) : super(key: key);

  final String image;
  final double width;
  final double height;
  final BoxFit fit;
  final String format;
  // final String holderImg = "brand_default${Random().nextInt(4) + 1}";
  final String holderImg = "brand_default${1}";
  final bool isWater;

  @override
  Widget build(BuildContext context) {
    if (TextUtil.isEmpty(image) || image == "null") {
      return LoadAssetImage(holderImg,
          height: height, width: width, fit: fit, format: format);
    } else {
      return CachedNetworkImage(
        imageUrl: Utils.getImagePath(image, isWater: isWater),
        placeholder: (context, url) =>
            LoadAssetImage(holderImg, height: height, width: width, fit: fit),
        errorWidget: (context, url, error) =>
            LoadAssetImage(holderImg, height: height, width: width, fit: fit),
        width: width,
        height: height,
        fit: fit,
      );
    }
  }
}