Example of JS detecting image size_javascript skills

Copy code The code is as follows:

< script type="text/javascript">
　var maxSize=document.getElementByIdx_x('MAX_FILE_SIZE').value;

function checkFileType(obj){

var path=obj. value.toString();

var perfix=path.substring(path.indexOf('.') 1);

var regExp=/(jpg|jpeg|gif|png)/ gi;

if(perfix.match(regExp)){

checkFileSize(obj); //If the image file type matches successfully, perform file size detection.

}else{

alert('Sorry, please select an image file'); return false;

} }
function checkFileSize(obj){

var img=new Image();

try{

var imgSize=obj.files.item(0).fileSize;

return isLarged(imgSize, maxSize); //Picture file size comparison.

}catch(e){ try{

img.src=obj.value;

return isLarged(img.fileSize,maxSize);

}catch(e){

obj.select();

var path=document.selection.createRange.text();

img.src=path;

return isLarged(img.fileSize,maxSize);

} } }
function isLarged(imgSize,maxSize){

if(imgSize>maxSize){

alert('Sorry, the image file you selected exceeds' parseInt(maxSize/1024) 'Kb');

return false;

}else{

alert(parseInt(imgSize/1024) 'kb ' 'This large is OK');

return true;

} }