Implementation code for JS file size judgment_image special effects

Method one, use ActiveX control to implement: Copy the code The code is as follows: function getFileSize(filePath) { var fso = new ActiveXObject("Scripting.FileSystemObject"); alert("File Size is: " fso.GetFile(filePath).size); } This method can be used in IE. If there are any shortcomings, there will be a security prompt. Changing the name to .hta will block the security prompts. Method 2, use the dynsrc attribute of img: Copy the code The code is as follows: function getFileSize(filePath) { var image=new Image(); image.dynsrc=filePath; alert(image.fileSize); } This method can be used in IE6, but cannot be used in IE7, IE8, Firefox, and chrome. Method three, use the fileSize of img: Copy the code The code is as follows: var ImgObj=new Image(); //Create an image object var AllImgExt=".jpg|.jpeg|.gif|.bmp|. png|"//All image format types var FileObj,ImgFileSize,ImgWidth,ImgHeight,FileExt,ErrMsg,FileMsg,HasCheked,IsImg//Global variable image related attributes //The following are restricted variables var AllowExt=".jpg|.gif|.doc|.txt|" //What types of files are allowed to be uploaded? For unlimited, add a "|" after each extension. Lowercase letters represent //var AllowExt=0 var AllowImgFileSize=70; //The size of the image file allowed to be uploaded. 0 is unlimited unit: KB var AllowImgWidth=500; //The width of the image file allowed to be uploaded is unlimited unit: px (pixel) var AllowImgHeight=500; //The height of the uploaded image is allowed? Unlimited unit: px (pixel) HasChecked=false; function CheckProperty(obj) //Detect image properties { FileObj=obj; if(ErrMsg!="") //Check whether the error message is returned for the correct image file and reset { ShowMsg(ErrMsg,false); return false; //Return } if(ImgObj.readyState!="complete") //If the image is not loaded, perform loop detection { setTimeout("CheckProperty(FileObj)", 500); return false; } ImgFileSize=Math.round(ImgObj.fileSize/1024*100)/100;//Get the size of the image file ImgWidth=ImgObj.width // Get the width of the picture ImgHeight=ImgObj.height; //Get the height of the picture FileMsg="nPicture size:" ImgWidth "*" ImgHeight "px"; FileMsg=FileMsg "nPicture file size :"ImgFileSize"Kb"; Please upload a file with a width smaller than " AllowImgWidth "px. The current image width is " ImgWidth "px"; if(AllowImgHeight!=0&&AllowImgHeight ErrMsg=ErrMsg "nThe image height exceeds the limit. Please upload a file with a height less than "AllowImgHeight"px. The current image height is "ImgHeight "px"; if(AllowImgFileSize!=0&&AllowImgFileSize ErrMsg=ErrMsg "nThe image file size exceeds the limit. Please upload files smaller than " AllowImgFileSize "KB, the current file size is " ImgFileSize "KB"; if(ErrMsg!="") ShowMsg(ErrMsg,false); else ShowMsg( FileMsg,true); } ImgObj.onerror=function(){ErrMsg='nThe picture format is incorrect or the picture is damaged!'} function ShowMsg(msg,tf) //Display prompt message tf=true displays file information tf=false displays error message msg-information content { msg=msg.replace("n"," "); msg=msg.replace( /n/gi," "); if(!tf) { document.all.UploadButton.disabled=true; FileObj.outerHTML=FileObj.outerHTML; MsgList.innerHTML=msg; HasChecked=false; } else { document.all.UploadButton.disabled=false; if(IsImg) PreviewImg.innerHTML=" " else PreviewImg.innerHTML="Non-image file"; MsgList.innerHTML=msg; HasChecked=true; } } function CheckExt(obj) { ErrMsg=""; FileMsg=""; FileObj=obj; IsImg=false; HasChecked=false; PreviewImg.innerHTML="Preview area"; if(obj.value=="")return false; MsgList.innerHTML="File information processing..."; document.all.UploadButton.disabled=true; FileExt=obj.value.substr(obj.value.lastIndexOf(".")) .toLowerCase(); if(AllowExt!=0&&AllowExt.indexOf(FileExt "|")==-1) //Determine whether the file type is allowed to be uploaded { ErrMsg="nThis file type is not allowed Upload allowed.Please upload a file of " AllowExt " type. The current file type is " FileExt; ShowMsg(ErrMsg,false); return false; } if(AllImgExt.indexOf(FileExt "|") !=-1) //If it is an image file, perform image information processing { IsImg=true; ImgObj.src=obj.value; CheckProperty(obj); return false; } else { FileMsg="nFile extension:" FileExt; ShowMsg(FileMsg,true); } } function SwitchUpType(tf) { if(tf) str=' ' else str=' ' document. all.file1.outerHTML=str; document.all.UploadButton.disabled=true; MsgList.innerHTML=""; } &lt ;legend> Image source Local Remote: Preview area It can be used in IE, FireFox, and chrome, but it only determines the size of the image file.

Implementation code for JS file size judgment_image special effects

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