小编Raj*_*han的帖子

我想在画布上拖动外部图像并且它与该画布对象相交时,找到画布中已经存在的对象.这是我用于拖放的代码:

if (Modernizr.draganddrop) {
    // Browser supports HTML5 DnD.
    // Bind the event listeners for the image elements
    var images = document.querySelectorAll('#images img');
    [].forEach.call(images, function (img) {
        img.addEventListener('dragstart', handleDragStart, false);
        img.addEventListener('dragend', handleDragEnd, false);
    });
    // Bind the event listeners for the canvas
    var canvasContainer = document.getElementById('canvas-container');
    canvasContainer.addEventListener('dragenter', handleDragEnter, false);
    canvasContainer.addEventListener('dragover', handleDragOver, false);
    canvasContainer.addEventListener('dragleave', handleDragLeave, false);
    canvasContainer.addEventListener('drop', handleDrop, false);
} else {
    // Replace with a fallback to a library solution.
    alert("This browser doesn't support the HTML5 Drag and Drop API."); …

我想,让字符串开始与大写字母和前两个字符应该不包含NL但其他字母像DE,BE等.

这是我在javascript中的方式

str.substring(0,2).match(/^[ABCDEFGHIJKLMOPQRSTUVWXYZ]+[ABCDEFGHIJKMNOPQRSTUVWXYZ]+$/)

我想将它缩短到范围.我尝试使用这些范围表达式[A-MO-Z],[AM] [OZ] +,但它们不起作用.

编辑:我尝试了这些表达式,但它们不起作用

str.substring(0,2).match(/^[A-MO-Z]+[A-KM-Z]+$/)
str.substring(0,2).match(/^[A-M][O-Z]+[A-K][M-Z]+$/)
str.substring(0,2).match(/^([A-M][O-Z])+([A-K][M-Z])+$/)