Javascript 绘制到画布时出现控制台错误
我有一个主javascript文件,它试图为一个游戏在画布上绘制一个tilemap,我有一个包含的文件,它实际上绘制了地图等,但我在firebug中遇到了这个错误: TypeError:无法将值转换为以下任意值:HTMLImageElement、HtmlCanvaElement、HTMLVideoElement。 [在此错误上中断] 调用my level.js文件的主js如下所示:Javascript 绘制到画布时出现控制台错误,javascript,canvas,map,tile,Javascript,Canvas,Map,Tile,我有一个主javascript文件,它试图为一个游戏在画布上绘制一个tilemap,我有一个包含的文件,它实际上绘制了地图等,但我在firebug中遇到了这个错误: TypeError:无法将值转换为以下任意值:HTMLImageElement、HtmlCanvaElement、HTMLVideoElement。 [在此错误上中断] 调用my level.js文件的主js如下所示: $(document).ready(function(){ var canvas = document.getE
$(document).ready(function(){
var canvas = document.getElementById("TBG");
var context = canvas.getContext("2d");
var ui = new Gui();
var level = new Level();
//----------Login/Register Gui --------------
$('#TBG').hide();
$('#load-new').hide();
$('#reg').hide();
$('#login').hide();
//if login_but is clicked do ui.login function
$('#login_but').click(ui.login);
//if reg_but is clicked do ui.register function
$('#reg_but').click(ui.register);
$('#new_but').click(function(){
game_settings("new");
});
$('#load_but').click(function(){
game_settings("load");
});
//if login_sumbit button is clicked do ui.login_ajax function
$("#login_submit").click(ui.login_ajax);
$("#reg_submit").click(ui.register_ajax);
$("#welcome").on("click", "#logout_but", ui.logout);
//____________________________________________
//Initialisation of game
function game_settings(state){
if(state == "load"){
ui.load_game();
//do ajax call to load user last save
//level.level_init(0,1);
draw();
}
else{
//set beginning params
//Change screens
ui.new_game();
alert("new game");
}
}
function draw () {
context.clearRect(0,0,canvas.width,canvas.height);
level.draw(context);
setTimeout(draw, 30);
}
// End Loop
});
function Level(){
var tilesize = 32;
var map = 0;
var mapTiles = [];
// var saved_level = level;
//var saved_location = location;
map = [
[1,1,1,1,1,1,1,1,1,1],
[2,2,2,2,2,2,2,2,2,2]
];
for (x = 1; x <= 256; x++) {
var imageObj = new Image(); // new instance for each image
imageObj.src = "images/prototype/"+x+".jpg";
mapTiles.push(imageObj);
}
this.draw = function(ctx) {
for (var x = 0; x <= 31; x++){
for ( var y = 0; y <= 31; y++){
ctx.drawImage(mapTiles[map[x][y]],x*tilesize, y*tilesize);
}
}
};
}
这行代码(level.js)所在的文件如下所示:
$(document).ready(function(){
var canvas = document.getElementById("TBG");
var context = canvas.getContext("2d");
var ui = new Gui();
var level = new Level();
//----------Login/Register Gui --------------
$('#TBG').hide();
$('#load-new').hide();
$('#reg').hide();
$('#login').hide();
//if login_but is clicked do ui.login function
$('#login_but').click(ui.login);
//if reg_but is clicked do ui.register function
$('#reg_but').click(ui.register);
$('#new_but').click(function(){
game_settings("new");
});
$('#load_but').click(function(){
game_settings("load");
});
//if login_sumbit button is clicked do ui.login_ajax function
$("#login_submit").click(ui.login_ajax);
$("#reg_submit").click(ui.register_ajax);
$("#welcome").on("click", "#logout_but", ui.logout);
//____________________________________________
//Initialisation of game
function game_settings(state){
if(state == "load"){
ui.load_game();
//do ajax call to load user last save
//level.level_init(0,1);
draw();
}
else{
//set beginning params
//Change screens
ui.new_game();
alert("new game");
}
}
function draw () {
context.clearRect(0,0,canvas.width,canvas.height);
level.draw(context);
setTimeout(draw, 30);
}
// End Loop
});
function Level(){
var tilesize = 32;
var map = 0;
var mapTiles = [];
// var saved_level = level;
//var saved_location = location;
map = [
[1,1,1,1,1,1,1,1,1,1],
[2,2,2,2,2,2,2,2,2,2]
];
for (x = 1; x <= 256; x++) {
var imageObj = new Image(); // new instance for each image
imageObj.src = "images/prototype/"+x+".jpg";
mapTiles.push(imageObj);
}
this.draw = function(ctx) {
for (var x = 0; x <= 31; x++){
for ( var y = 0; y <= 31; y++){
ctx.drawImage(mapTiles[map[x][y]],x*tilesize, y*tilesize);
}
}
};
}
功能级别(){
var tilesize=32;
var-map=0;
var-mapTiles=[];
//var保存的\u级别=级别;
//var保存位置=位置;
地图=[
[1,1,1,1,1,1,1,1,1,1],
[2,2,2,2,2,2,2,2,2,2]
];
对于(x=1;x忘掉画布和其他一切,看看map
数组和使用它的代码。让我们撕掉画布代码,用一些console.log()调用检查数组访问:
map = [
[1,1,1,1,1,1,1,1,1,1],
[2,2,2,2,2,2,2,2,2,2]
];
console.log( map.length );
console.log( map[0].length );
for (var x = 0; x <= 31; x++){
for ( var y = 0; y <= 31; y++){
console.log( x, y, map[x], map[x] && map[x][y] );
}
}
当map[x][y]
是未定义的时,这个表达式的计算结果是什么?苏格拉底,是你吗?:p回答:我们试图访问超出我们实际设置的元素数量的map数组元素。(嗨,迈克尔·盖里,我已经足够大了,在大学里我是用苏格拉底的方法学习的!)柏拉图!见到你真高兴,老朋友。是的,另一种说法是“mapTiles[未定义]
的计算结果是什么?”我们的朋友亚里士多德怎么样?你最近有没有收到他的来信?我一直想问他溢出堆栈意味着什么。