Asp.Net平台下的图片在线裁剪功能的实现代码(源码打包)

<link href="Styles/jquery.Jcrop.css" rel="stylesheet" type="text/css" />

<script src="Scripts/jquery-1.4.1.js" type="text/javascript"></script>

<script src="Scripts/jquery.Jcrop.js" type="text/javascript"></script>

<asp:Label ID="Label1" Text="原始图片" runat="server"></asp:Label><br />

<asp:Image ID="target" runat="server" />

<br />

<asp:Label ID="Label2" runat="server" Text="最终显示效果"></asp:Label>

<div id="preImg" style="width: 150px; height: 80px; overflow: hidden;">

<asp:Image ID="preview" alt="Preview" runat="server" />

</div>

$('#target').Jcrop({

onChange: updatePreview,

onSelect: updatePreview,

onRelease: clearCoords,

aspectRatio: 150 / 80,

minSize: _minarray,

setSelect: _array

}, function () {

var bounds = this.getBounds();

boundx = bounds[0];

boundy = bounds[1];

jcrop_api = this;

});

//此方法是用来及时展现图片裁剪效果

function updatePreview(c) {

if (parseInt(c.w) > 0) {

var rx = 150 / c.w;

var ry = 80 / c.h;

var _width;

var _height;

if (Math.round(rx * boundx) > $targetImg.width()) {

_width = $targetImg.width();

}

else {

_width = Math.round(rx * boundx);

}

if (Math.round(ry * boundy) > $targetImg.height()) {

_height = $targetImg.height();

}

else {

_height = Math.round(ry * boundy);

}

$('#preview').css({

width: _width + 'px',

height: _height + 'px',

marginLeft: '-' + Math.round(rx * c.x) + 'px',

marginTop: '-' + Math.round(ry * c.y) + 'px'

});

}

$('#x1').val(c.x);

$('#y1').val(c.y);

$('#Iwidth').val(c.w);

$('#Iheight').val(c.h);

};

<form id="Form1" runat="server">

<asp:HiddenField ID="HdnNewImgPath" runat="server" />

<asp:HiddenField ID="x1" runat="server" />

<asp:HiddenField ID="y1" runat="server" />

<asp:HiddenField ID="Iwidth" runat="server" />

<asp:HiddenField ID="Iheight" runat="server" />

<br />

<asp:Button ID="SaveImg" runat="server" Text="裁剪并保存图片" OnClick="saveImg" OnClientClick="return CheckIMG()" />

</form>

using System.Drawing;

using System.Drawing.Imaging;

using System.Drawing.Design;

protected void saveImg(object sender, EventArgs e)

{

if (IsPostBack)

{

string tempurl = Path.Combine(ConfigAccess.UploadImagePath, _url);

int startX = int.Parse(x1.Value);

int startY = int.Parse(y1.Value);

int width = int.Parse(Iwidth.Value);

int height = int.Parse(Iheight.Value);

ImgReduceCutOut(startX, startY, width, height, tempurl, tempurl);

this.target.Visible = false;

this.Label1.Visible = false;

this.SaveImg.Enabled = false;

}

}

//通过连接创建Image对象

System.Drawing.Image oldimage = System.Drawing.Image.FromFile(input_ImgUrl);

oldimage.Save(Server.MapPath("temp.jpg"));//把原图Copy一份出来,然后在temp.jpg上进行裁剪,最后把裁剪后的图片覆盖原图 oldimage.Dispose();//一定要释放临时图片,要不之后的在此图上的操作会报错,原因冲突 Bitmap bm = new Bitmap(Server.MapPath("temp.jpg"));

//处理JPG质量的函数

ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();

ImageCodecInfo ici = null;

foreach (ImageCodecInfo codec in codecs)

{

if (codec.MimeType == "image/jpeg")

{

ici = codec;

break;

}

}

EncoderParameters ep = new EncoderParameters();

ep.Param[0] = new EncoderParameter(Encoder.Quality, (long)level);

// 裁剪图片

Rectangle cloneRect = new Rectangle(startX, startY, int_Width, int_Height);

PixelFormat format = bm.PixelFormat;

Bitmap cloneBitmap = bm.Clone(cloneRect, format);

if (int_Width > int_Standard_Width)

{

//缩小图片

System.Drawing.Image cutImg = cloneBitmap.GetThumbnailImage(int_Standard_Width, int_Standard_Height, new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback), IntPtr.Zero);

cutImg.Save(out_ImgUrl, ici, ep);

cutImg.Dispose();

}

else

{

//保存图片

cloneBitmap.Save(out_ImgUrl, ici, ep);

}

cloneBitmap.Dispose();

bm.Dispose();

}

public bool ThumbnailCallback()

{

return false;

}