Uploaded images, image size verification, image preview effect code based on jquery_jquery

jquery implements uploaded images and image size verification, image preview effect code
Uploaded image verification

Copy code The code is as follows:

*/
function submit_upload_picture(){
var file = $('file_c').value;
if(!/.(gif|jpg |jpeg|png|gif|jpg|png)$/.test(file)){
alert("The picture type must be one of .gif, jpeg, jpg, png")
}else{
$('both_form').action="file!upload.action";
$('both_form').submit();
$('insert_img').sethtml('');
$('display_div').setstyle('display', 'block');
$ ('upload_div').setstyle('display', 'none');
}
}

Verification of image type and size

Copy code The code is as follows:

//Example 2
function validate_edit_logo(a){
var file = $('file').value;
if(!/.(gif|jpg|jpeg|png|gif|jpg|png)$/.test(file)){
alert(" The image type must be one of .gif, jpeg, jpg, png")
if(a==1){
return false;
}
}else{
var image = new image();
image.src = file;
var height = image.height;
var width = image.width;
var filesize = image.filesize;
$( 'beforeend').src=file;
$('div_regi_right').setstyle('display', 'block');
if(width>80 && height>80 && filesize>102400){
alert('Please upload an image of 80*80 pixels or less than 100k');
if(a==1){
return false;
}
}
if(a ==1){
return true;
}
}
}

Picture preview

Copy code The code is as follows:

//Example 3
function viewimg(index) {
var name = 'uploadimg' index;
var imgup = $(name);
var imgpath = getpath(imgup);
var local = imgup.value;
var point = local.lastindexof(".");
//Determine the size of the uploaded file
var img = document.createelement("img");
img.src = local;
var filesize = img.filesize;
img.onload = function (){filesize=this.filesize;}
if(img.filesize>5242880){
alert("The image file is too large! ");
return false;
}
//Determine whether it is an image format
var imgname = imgup.value.substring(imgup.value.lastindexof("."), imgup.value. length);
imgname = imgname.tolowercase();
if ((imgname != ".jpg") && (imgname != ".gif") && (imgname != ".jpeg") && ( imgname != ".png") && (imgname != ".bmp")) {
alert("u8bf7u9009u62e9u56feu7247u6587u4ef6uff0cu8c22u8c22!");
imgup.focus();
//Clear the value in file www.3ppt.com
imgup.select();
document.selection.clear();
} else {
//Display image
document.getelementbyid("sig_preview" index) .innerhtml = "";
}
if (index >=3){
var cnt = index 1;
$("img" cnt).style. display = "";
}
}