
ImageViewer 图片
图片容器,在保留原生 img 的特性下,支持懒加载,自定义占位、加载失败等
基本用法
加载并显示图片文件
Demo
object-fit: fill
填充 默认值 使图片拉伸填满整个容器, 不保证保持原有的比例object-fit: contain
包含 保持原有尺寸比例缩放 保证整个图片都可以出现在容器中,因此此参数可能会在容器内留下空白object-fit: cover
覆盖 保持原有尺寸比例缩放,宽度和高度至少有一个和容器一致(尺寸小的一致)因此此参数可能会让图片部分区域不可见object-fit: none
无 保持原有尺寸比例,同时保持图片原始尺寸大小,多出的部分隐藏object-fit: scale-down
降低 就好像依次设置了 none 或 contain 最终呈现的是尺寸比较小的那个
Fill

Contain

Cover

None

ScaleDown

占位内容
可通过设置 ShowPlaceHolder
开启占位符功能,通过设置 PlaceHolderTemplate
自定义占位内容
Demo
图片加载后浏览器默认会缓存,建议 F12 关闭缓存体验此功能
默认

Loading...
自定义

加载中 ...
占位模板
可通过设置 PlaceHolderTemplate
开启占位模板功能,未设置 Url
或者正在加载时显示此模板内容
Demo
图片加载后浏览器默认会缓存,建议 F12 关闭缓存体验此功能
未设置 Url
占位模板
加载时显示

占位模板
加载失败
可通过设置 ErrorTemplate
开启错误模板功能,参数 Url
无法加载图片时显示此模板内容
Demo
Url 路径错误

自定义

大图预览
可通过设置 PreviewList
开启预览大图的功能
Demo


Attributes
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@page "/imageviewers"
<h3>ImageViewer 图片</h3>
<h4>图片容器,在保留原生 img 的特性下,支持懒加载,自定义占位、加载失败等</h4>
<DemoBlock Title="基本用法" Introduction="加载并显示图片文件" Name="Normal">
<ul class="ul-demo">
<li><code>object-fit: fill</code> 填充 默认值 使图片拉伸填满整个容器, 不保证保持原有的比例</li>
<li><code>object-fit: contain</code> 包含 保持原有尺寸比例缩放 保证整个图片都可以出现在容器中,因此此参数可能会在容器内留下空白</li>
<li><code>object-fit: cover</code> 覆盖 保持原有尺寸比例缩放,宽度和高度至少有一个和容器一致(尺寸小的一致)因此此参数可能会让图片部分区域不可见</li>
<li><code>object-fit: none</code> 无 保持原有尺寸比例,同时保持图片原始尺寸大小,多出的部分隐藏</li>
<li><code>object-fit: scale-down</code> 降低 就好像依次设置了 <b>none</b> 或 <b>contain</b> 最终呈现的是尺寸比较小的那个</li>
</ul>
<div class="images mt-3">
<div class="images-item">
<div>Fill</div>
<ImageViewer Url="_content/BootstrapBlazor.Shared/images/bird.jpeg" FitMode="ObjectFitMode.Fill" />
</div>
<div class="images-item">
<div>Contain</div>
<ImageViewer Url="_content/BootstrapBlazor.Shared/images/bird.jpeg" FitMode="ObjectFitMode.Contain" />
</div>
<div class="images-item">
<div>Cover</div>
<ImageViewer Url="_content/BootstrapBlazor.Shared/images/bird.jpeg" FitMode="ObjectFitMode.Cover" />
</div>
<div class="images-item">
<div>None</div>
<ImageViewer Url="_content/BootstrapBlazor.Shared/images/bird.jpeg" FitMode="ObjectFitMode.None" />
</div>
<div class="images-item">
<div>ScaleDown</div>
<ImageViewer Url="_content/BootstrapBlazor.Shared/images/bird.jpeg" FitMode="ObjectFitMode.ScaleDown" />
</div>
</div>
</DemoBlock>
<DemoBlock Title="占位内容" Introduction="可通过设置 <code>ShowPlaceHolder</code> 开启占位符功能,通过设置 <code>PlaceHolderTemplate</code> 自定义占位内容" Name="PlaceHolder">
<div>图片加载后浏览器默认会缓存,建议 <kbd>F12</kbd> 关闭缓存体验此功能</div>
<div class="images img-ph mt-3">
<div class="images-item">
<div>默认</div>
<ImageViewer Url="_content/BootstrapBlazor.Shared/images/image-ph.jpeg" ShowPlaceHolder="true" />
</div>
<div class="images-item">
<div>自定义</div>
<ImageViewer Url="_content/BootstrapBlazor.Shared/images/image-ph.jpeg" ShowPlaceHolder="true">
<PlaceHolderTemplate>
<div class="bb-img-holder">
<div class="bb-img-loading">加载中 ...</div>
</div>
</PlaceHolderTemplate>
</ImageViewer>
</div>
</div>
</DemoBlock>
<DemoBlock Title="占位模板" Introduction="可通过设置 <code>PlaceHolderTemplate</code> 开启占位模板功能,未设置 <code>Url</code> 或者正在加载时显示此模板内容" Name="PlaceHolderTemplate">
<div>图片加载后浏览器默认会缓存,建议 <kbd>F12</kbd> 关闭缓存体验此功能</div>
<div class="images img-ph mt-3">
<div class="images-item">
<div>未设置 Url</div>
<ImageViewer Url="">
<PlaceHolderTemplate>
<div class="bb-img-holder">
<div class="bb-img-loading">占位模板</div>
</div>
</PlaceHolderTemplate>
</ImageViewer>
</div>
<div class="images-item">
<div>加载时显示</div>
<ImageViewer Url="_content/BootstrapBlazor.Shared/images/image-ph.jpeg" ShowPlaceHolder="true">
<PlaceHolderTemplate>
<div class="bb-img-holder">
<div class="bb-img-loading">占位模板</div>
</div>
</PlaceHolderTemplate>
</ImageViewer>
</div>
</div>
</DemoBlock>
<DemoBlock Title="加载失败" Introduction="可通过设置 <code>ErrorTemplate</code> 开启错误模板功能,参数 <code>Url</code> 无法加载图片时显示此模板内容" Name="ErrorTemplate">
<div class="images img-ph mt-3">
<div class="images-item">
<div>Url 路径错误</div>
<ImageViewer Url="_content/BootstrapBlazor.Shared/images/error-image.jpeg" HandleError="true" />
</div>
<div class="images-item">
<div>自定义</div>
<ImageViewer Url="_content/BootstrapBlazor.Shared/images/error-image.jpeg">
<ErrorTemplate>
<div class="bb-img-holder">
<div class="bb-img-loading">加载失败</div>
</div>
</ErrorTemplate>
</ImageViewer>
</div>
</div>
</DemoBlock>
<DemoBlock Title="大图预览" Introduction="可通过设置 <code>PreviewList</code> 开启预览大图的功能" Name="PreviewList">
<div class="images img-ph mt-3">
<div class="images-item">
<ImageViewer Url="_content/BootstrapBlazor.Shared/images/bird.jpeg" PreviewList="PreviewList" />
</div>
</div>
</DemoBlock>
<AttributeTable Items="@GetAttributes()" />
// Copyright (c) Argo Zhang (argo@163.com). All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
// Website: https://www.blazor.zone or https://argozhang.github.io/
using BootstrapBlazor.Components;
using BootstrapBlazor.Shared.Common;
namespace BootstrapBlazor.Shared.Samples;
/// <summary>
/// Images 示例类
/// </summary>
public partial class ImageViewers
{
private List<string> PreviewList { get; } = new();
/// <summary>
/// OnInitialized 方法
/// </summary>
protected override void OnInitialized()
{
base.OnInitialized();
PreviewList.AddRange(new string[]
{
"_content/BootstrapBlazor.Shared/images/ImageList1.jpeg",
"_content/BootstrapBlazor.Shared/images/ImageList2.jpeg"
});
}
private static IEnumerable<AttributeItem> GetAttributes() => new AttributeItem[]
{
new AttributeItem() {
Name = nameof(ImageViewer.Url),
Description = "图片 Url",
Type = "string",
ValueList = " — ",
DefaultValue = " — "
},
new AttributeItem() {
Name = nameof(ImageViewer.Alt),
Description = "原生 alt 属性",
Type = "string",
ValueList = " — ",
DefaultValue = " — "
},
new AttributeItem() {
Name = nameof(ImageViewer.ShowPlaceHolder),
Description = "是否显示占位符 适用于大图片加载",
Type = "bool",
ValueList = "true|false",
DefaultValue = "false"
},
new AttributeItem() {
Name = nameof(ImageViewer.HandleError),
Description = "加载失败时是否显示错误占位符",
Type = "bool",
ValueList = "true|false",
DefaultValue = "false"
},
new AttributeItem() {
Name = nameof(ImageViewer.PlaceHolderTemplate),
Description = "占位模板 未设置 Url 或者正在加载大图时生效",
Type = "RenderFragment",
ValueList = "true|false",
DefaultValue = "false"
},
new AttributeItem() {
Name = nameof(ImageViewer.ErrorTemplate),
Description = "错误模板 图片路径错误时生效",
Type = "RenderFragment",
ValueList = "true|false",
DefaultValue = "false"
},
new AttributeItem() {
Name = nameof(ImageViewer.FitMode),
Description = "原生 object-fit 属性",
Type = "ObjectFitMode",
ValueList = "fill|contain|cover|none|scale-down",
DefaultValue = "fill"
},
new AttributeItem() {
Name = nameof(ImageViewer.ZIndex),
Description = "原生 z-index 属性",
Type = "int",
ValueList = " — ",
DefaultValue = "2050"
},
new AttributeItem() {
Name = nameof(ImageViewer.PreviewList),
Description = "预览大图链接集合",
Type = "List<string>",
ValueList = " — ",
DefaultValue = " — "
},
new AttributeItem() {
Name = nameof(ImageViewer.OnLoadAsync),
Description = "图片加载成功时回调方法",
Type = "Func<string, Task>",
ValueList = " — ",
DefaultValue = " — "
},
new AttributeItem() {
Name = nameof(ImageViewer.OnErrorAsync),
Description = "图片加载失败时回调方法",
Type = "Func<string, Task>",
ValueList = " — ",
DefaultValue = " — "
}
};
}