如何在自定义表单操作Sharepoint Designer中获取当前项

尝试使用以下javascript函数:

function GetQueryVariable(variable) {
    var query = window.location.search.substring(1);
    var vars = query.split("&");
    for (var i = 0; i < vars.length; i++) {
        var pair = vars[i].split("=");
        if (pair[0] == variable) {
            return pair[1];
        }
    }
}

function GetCurrentItem() {
    var itemId = GetQueryVariable("ID");
    try {
        var context = new SP.ClientContext.get_current();
        var web = context.get_web();
        var list = web.get_lists().getByTitle('list-title');
        this.currItem = list.getItemById(itemId);

        context.load(currItem);
        context.executeQueryAsync(Function.createDelegate(this, this.funcSuccess), Function.createDelegate(this, this.funcFailed));
    }
    catch (e) {
        alert(e);
    }
}

function funcSuccess() {}
function funcFailed() {}