javascript+canvas制作九宫格小程序

js核心代码

/*

 *canvasid:html canvas标签id

 *imageid:html img 标签id

 *gridcountX:x轴图片分割个数

 *gridcountY:y轴图片分割个数

 *gridspace:宫格空隙

 *offsetX：x*y宫格相对canvas（0，0）X坐标偏移量

 **offsetX：x*y宫格相对canvas（0，0）Y坐标偏移量

 *isanimat：是否启用动画显示

 */

function ImageGrid(canvasid, imageid, gridcountX, gridcountY, gridspace, offsetX, offsetY, isanimat) {

    var image = new Image();

    var g = document.getElementById(canvasid).getContext("2d");

    var img=document.getElementById(imageid);

    image.src=img.getAttribute("src");

    g.drawImage(image, 0, 0);

    var imagedata = g.getImageData(0, 0, image.width, image.height);

    var grid_width = imagedata.width / gridcountX;

    var grid_height = imagedata.height / gridcountY;

    //动画

    if (isanimat) {

        var x = 0,

            y = 0;

        var inter = setInterval(function() {

            g.putImageData(imagedata, gridspace * x + offsetX, gridspace * y + offsetY, grid_width * x, grid_height * y, grid_width, grid_height);

            x < gridcountX ? x++ : x = 0;

            if (x == 0) {

                y < gridcountY ? y++ : y = 0;

            }

        }, 200);

        y == gridcountY ? clearInterval(inter) : null;

    } else { //非动画

        for (var y = 0; y < gridcountY; y++) {

            for (var x = 0; x < gridcountX; x++) {

                g.putImageData(imagedata, gridspace * x + offsetX, gridspace * y + offsetY, grid_width * x, grid_height * y, grid_width, grid_height);

            }

        }

    }

}

html代码

<canvas id="canvas1" width="900px" height="550px">Canvas demo</canvas>

 <img id="image1" style="display:none" src="//img.jbzj.com/file_images/article/201412/2014122894620636.jpg"/>

使用方法：

//eg...

ImageGrid("canvas1", "image1", 3, 3, 2, 220, 0, true); //3*3

ImageGrid("canvas1", "image1", 4, 4, 2, 440, 0, true); //4*4

ImageGrid("canvas1", "image1", 3, 4, 2, 660, 0, false); //3*4

代码很简洁，效果却非常炫酷，小伙伴们学会了吗？