Javascript 带超时的canvas drawimage循环
我正在尝试用canvas对象编写一个小型流式客户端 这是必要的代码:Javascript 带超时的canvas drawimage循环,javascript,loops,canvas,stream,Javascript,Loops,Canvas,Stream,我正在尝试用canvas对象编写一个小型流式客户端 这是必要的代码: this.drawPictures = function() { var i = 0; while (i <= 3000) { this.addPicture("Pictures/Wildlife/" + i + '.bmp', 1, 1); i = i + 4; } } 有人知道为什么它与alert一起工作,而与addPicture不一起工作吗?因为当我不使用
this.drawPictures = function() {
var i = 0;
while (i <= 3000) {
this.addPicture("Pictures/Wildlife/" + i + '.bmp', 1, 1);
i = i + 4;
}
}
有人知道为什么它与alert一起工作,而与addPicture不一起工作吗?因为当我不使用时间戳(第一个代码示例)时,它工作得很好 在ctx.drawImage中,imageObj后面的两个参数是X/Y而不是图像大小 您需要留出足够的时间加载图像(1秒不够) addPicture开始(但未完成)加载图像,但在再次调用addPicture时图像尚未完全加载 有很多图像加载程序…这里有一个:
var imageURLs=[]; // put the paths to your images here
var imagesOK=0;
var imgs=[];
imageURLs.push("myPicture1.png");
imageURLs.push("myPicture2.png");
imageURLs.push("myPicture3.png");
imageURLs.push("myPicture4.png");
loadAllImages(start);
function loadAllImages(callback){
for (var i=0; i<imageURLs.length; i++) {
var img = new Image();
imgs.push(img);
img.onload = function(){
imagesOK++;
if (imagesOK>=imageURLs.length ) {
callback();
}
};
img.onerror=function(){alert("image load failed");}
img.crossOrigin="anonymous";
img.src = imageURLs[i];
}
}
function start(){
// the imgs[] array holds fully loaded images
// the imgs[] are in the same order as imageURLs[]
// Start your timer and display your pictures with addPicture
}
var-imageURLs=[];//将图像的路径放在这里
var-imagesOK=0;
var-imgs=[];
push(“myPicture1.png”);
push(“myPicture2.png”);
push(“myPicture3.png”);
push(“myPicture4.png”);
加载图像(开始);
函数LoadAllImage(回调){
for(var i=0;i=imageURL.length){
回调();
}
};
img.onerror=function(){alert(“映像加载失败”);}
img.crossOrigin=“匿名”;
img.src=imageURL[i];
}
}
函数start(){
//imgs[]数组保存完全加载的图像
//imgs[]与ImageURL[]的顺序相同
//启动计时器并使用addPicture显示图片
}
this.addPicture = function (cPicPath, nSizeX, nSizeY) {
var imageObj = new Image();
imageObj.onload = function () {
ctx.drawImage(imageObj, nSizeX, nSizeY);
}
imageObj.src = cPicPath;
}
var imageURLs=[]; // put the paths to your images here
var imagesOK=0;
var imgs=[];
imageURLs.push("myPicture1.png");
imageURLs.push("myPicture2.png");
imageURLs.push("myPicture3.png");
imageURLs.push("myPicture4.png");
loadAllImages(start);
function loadAllImages(callback){
for (var i=0; i<imageURLs.length; i++) {
var img = new Image();
imgs.push(img);
img.onload = function(){
imagesOK++;
if (imagesOK>=imageURLs.length ) {
callback();
}
};
img.onerror=function(){alert("image load failed");}
img.crossOrigin="anonymous";
img.src = imageURLs[i];
}
}
function start(){
// the imgs[] array holds fully loaded images
// the imgs[] are in the same order as imageURLs[]
// Start your timer and display your pictures with addPicture
}