jQuery上傳預覽之前的最大高度和最大寬度驗證

Question

好的，所以我嘗試在jquery上傳預覽之前進行最大高度最大寬度驗證，以便如果圖像大於最大高度或最大寬度來提醒用戶並要求他們選擇較小的照片。 我將如何執行那部分代碼？

html代碼：

<img id="uploadPreview" style="display:none;"/>

<!-- image uploading form -->
<form action="upload.php" method="post" enctype="multipart/form-data">
<input id="uploadImage" type="file" accept="image/jpeg" name="image" />
<input type="submit" value="Upload">

<!-- hidden inputs -->
<input type="hidden" id="x" name="x" />
<input type="hidden" id="y" name="y" />
<input type="hidden" id="w" name="w" />
<input type="hidden" id="h" name="h" />
</form>

jQuery代碼：

function setInfo(i, e) {
    $('#x').val(e.x1);
    $('#y').val(e.y1);
    $('#w').val(e.width);
    $('#h').val(e.height);
}

$(document).ready(function() {
    var p = $("#uploadPreview");

    // prepare instant preview
    $("#uploadImage").change(function(){
        // fadeOut or hide preview
        p.fadeOut();

        // prepare HTML5 FileReader
        var oFReader = new FileReader();
        oFReader.readAsDataURL(document.getElementById("uploadImage").files[0]);

        oFReader.onload = function (oFREvent) {
            p.attr('src', oFREvent.target.result).fadeIn();
        };
    });

    // implement imgAreaSelect plug in (http://odyniec.net/projects/imgareaselect/)
    $('img#uploadPreview').imgAreaSelect({
        // set crop ratio (optional)
        aspectRatio: '1:1',
        onSelectEnd: setInfo
    });
});

Answer 1

只需將您的script.js替換為

function setInfo(i, e) {
    $('#x').val(e.x1);
    $('#y').val(e.y1);
    $('#w').val(e.width);
    $('#h').val(e.height);
}
$(document).ready(function () {
    var p = $("#uploadPreview");
    // prepare instant preview
    $("#uploadImage").change(function () {
        var that=this;
        // fadeOut or hide preview
        p.fadeOut();
        // prepare HTML5 FileReader
        var oFReader = new FileReader();
        oFReader.readAsDataURL(document.getElementById("uploadImage").files[0]);
        oFReader.onload = function (oFREvent) {
            var image = new Image();
            image.src = oFREvent.target.result;
            image.onload = function () {
                if ((this.width > 400) && (this.height)) {
                    that.value="";
                    alert("choose another file");
                }
                else {
                    p.attr('src', oFREvent.target.result).fadeIn();
                }
                // access image size here & do further implementation
            };
        };
    });
    // implement imgAreaSelect plug in (http://odyniec.net/projects/imgareaselect/)
    $('img#uploadPreview').imgAreaSelect({
        // set crop ratio (optional)
        aspectRatio: '1:1',
        onSelectEnd: setInfo,
        maxHeight: 100,
        maxWidth: 100
    });
});

我會幫你的..