话不多说。

html代码：一个from包裹的html

<div class="form-group" id="uploadForm">

<div class="h4">头像预览</div>

<div class="fileinput fileinput-new" data-provides="fileinput" id="exampleInputUpload">

<div class="fileinput-new thumbnail" style="width: 200px;height: auto;max-height:150px;">

@if (!string.IsNullOrEmpty(Model.User.Image))

{

<img id='picImg' style="width: 100%;height: auto;max-height: 140px;" src="@Model.User.Image" alt="" />

}

</div>

<div id="im" class="fileinput-preview fileinput-exists thumbnail" style="max-width: 200px; max-height: 150px;"></div>

<div>

<span class="btn btn-primary btn-file">

<span class="fileinput-new">选择文件</span>

<span class="fileinput-exists">换一张</span>

<input type="file" name="pic1" id="picID" accept="image/gif,image/jpeg,image/x-png" />

</span>

<a href="javascript:;" class="btn btn-warning fileinput-exists" data-dismiss="fileinput">移除</a>

</div>

</div>

</div>

<p>头像文件仅支持gif、png、jpg文件</p>

<button type="button" id="uploadSubmit" class="btnZHBlue mTop10">提交</button>

 

后台代码：

public ActionResult Update(int id)//上传头像

{

string all = Request["image"].ToString();//这是base64编码，直接保存数据库。

if (all == null)

{

return Json(false);

}

else

{

return Json(true);

}

}