关于jQuery - 图片库

Question

$("#right").click(function(){
    var nextIndex=currIndex.next();

    var nextImg = nextIndex.children("img").attr("src");
    $("#main").attr("src",nextImg);

    currIndex = nextIndex;

}); 

$("#left").click(function(){
    var prevIndex=currIndex.prev();

    var prevImg = prevIndex.children("img").attr("src");
    $("#main").attr("src",prevImg);

    currIndex = prevIndex;

});  

当我在最后一张图片中时，右箭头或左箭头不起作用。

Answer 1

我认为您收到错误是因为变量未定义，我建议您检查下一个或前一个元素是否存在。

$("#right").click(function(){ 
  var nextIndex = currIndex.next();
  if (typeof nextIndex !== "undefined") {
    var nextImg = nextIndex.children("img").attr("src");
    $("#main").attr("src",nextImg);

    currIndex = nextIndex;
  }


}); 

$("#left").click(function(){
  var prevIndex=currIndex.prev();
  if (typeof prevIndex !== "undefined") {
    var prevImg = prevIndex.children("img").attr("src");
    $("#main").attr("src",prevImg);

    currIndex = prevIndex;
  }

});