Javascript 调用类函数

Question

我正在尝试调用类函数:

// Gantt chart object
function ganttChart(gContainerID) {

    this.isDebugMode = true;                                    // Is this chart in debug mode
    this.gContainer = document.getElementById(gContainerID);    // The container the chart is built inside
    this.gDebugPannel;                                          // Debug pannel

    // Create debug pannel
    if (this.isDebugMode) {
        this.gContainer.innerHTML += "<div id=\"gDebug" + gContainerID + "\" class=\"gDebug\">cometishian</div>";
        this.gDebugPannel = document.getElementById("gDebug" + gContainerID);
    }

    gDebug("lmfao!");

// Updates debug information
function gDebug(debugMessage) {
    alert(this.gDebugPannel.innerHTML);
    if (this.isDebugMode) { this.gDebugPannel.innerHTML = debugMessage; }
}
}

我希望它提醒“cometishian”，但 this.gDebugPannel.innerHTML 为空，有什么想法吗？

经进一步调查，this.gDebugPannel 未定义。

更新:

// Gantt chart object
function ganttChart(gContainerID) {

    this.isDebugMode = true;                                    // Is this chart in debug mode
    this.gContainer = document.getElementById(gContainerID);    // The container the chart is built inside
    this.gDebugPannel;                                          // Debug pannel
    this.gPosX;
    this.gPosY;

    // Create debug pannel
    if (this.isDebugMode) {
        this.gContainer.innerHTML += "<div id=\"gDebug" + gContainerID + "\" class=\"gDebug\">5,5 | 5.1</div>";
        this.gDebugPannel = document.getElementById("gDebug" + gContainerID);
    }

    // Updates debug information
    ganttChart.gDebug = function(debugMessage) {
        if (this.isDebugMode) { this.gDebugPannel.innerHTML = debugMessage; }
    }

    this.gDebug("wo");

}

this.gDebug("wo") 抛出的行:

网页错误详细信息

用户代理:Mozilla/4.0(兼容；MSIE 8.0；Windows NT 5.1；Trident/4.0；InfoPath.1；.NET CLR 2.0.50727；.NET CLR 3.0.04506.648；.NET CLR 3.5.21022；.NET CLR 1.1.4322；.NET CLR 3.0.4506.2152；.NET CLR 3.5.30729；OfficeLiveConnector.1.4；OfficeLivePatch.1.3)时间戳:2010 年 11 月 25 日星期四 12:57:51 UTC

Message: Object doesn't support this property or method
Line: 21
Char: 5
Code: 0
URI: http://server1/bb/ganttnew/gMain.js

Answer 1

您需要在 this 实例上调用该函数，如下所示:

gDebug.call(this, "Hi!");

正确的做法是将函数放在类原型(prototype)中:(这应该在声明构造函数之后完成)

ganttChart.prototype.gDebug = function(debugMessage) {
    alert(this.gDebugPannel.innerHTML);
    if (this.isDebugMode) { this.gDebugPannel.innerHTML = debugMessage; }
}

this.gDebug("Hi!");