為什么我到他顯示出1的時(shí)候我的顯示不出來(lái)
var WINDOW_WIDTH = 1024;
var WINDOW_HEIGHT = 768;
var RADIUS = 8;
window.onload = function(){
??? var canvas = document.getElementById('canvas');
??? var context = canvas.getContext("2d");
??? canvas.width = WINDOW_WIDTH;
??? canvas.height = WINDOW_HEIGHT;
??? render( context )
}
function render( cxt ){
??? var hours = 12;
??? var minutes = 34;
??? var seconds = 56;
???? renderDigit(10,10,parseInt( hours/10 ),context);
}
function renderDigit( x , y , num , cxt ){
??? cxt.fillStyle = "rgb(0,102,153)";
??? for( var i = 0 ; i < digit[num].length ; i ++ )
??????? for(var j = 0 ; j < digit[num][i].length ; j ++ )
??????????? if( digit[num][i][j] == 1 ){
??????????????? cxt.beginPath();
??????????????? cxt.arc( x+j*2*(RADIUS+1)+(RADIUS+1) , y+i*2*(RADIUS+1)+(RADIUS+1) , RADIUS , 0 , 2*Math.PI )
??????????????? cxt.closePath()
??????????????? cxt.fill()
??????????? }
}
2017-11-10
第一個(gè)錯(cuò)誤:少了一個(gè)*
renderDigit(MARGIN_LEFT+15(RADIUS+1),MARGIN_TOP,parseInt(hours%10),cxt);
renderDigit(MARGIN_LEFT+15*(RADIUS+1),MARGIN_TOP,parseInt(hours%10),cxt);
第二個(gè)錯(cuò)誤:少了一個(gè)大括號(hào)
for(var j=0;j<digit[num][i].length;j++)
for(var j=0;j<digit[num][i].length;j++){
2017-10-08
?哪里有錯(cuò)嗎?為什么瀏覽器中什么都不顯示?
var WINDOW_WIDTH=1024;
var WINDOW_HEIGHT=768;
var RADIUS=8;
var MARGIN_TOP=60;
var MARGIN_LEFT=30;
window.onload=function(){
?? ?var canvas=document.getElementById('canvas');
?? ?var context=canvas.getContext("2d");
?? ?canvas.width=WINDOW_WIDTH;
?? ?canvas.height=WINDOW_HEIGHT;
?? ?render(context);
}
function render(cxt){
?? ?var hours=12;
?? ?var minutes=34;
?? ?var seconds=56;
?? ?renderDigit(MARGIN_LEFT,MARGIN_TOP,parseInt(hours/10),cxt);
?? ?renderDigit(MARGIN_LEFT+15(RADIUS+1),MARGIN_TOP,parseInt(hours%10),cxt);
?? ?renderDigit(MARGIN_LEFT+30*(RADIUS+1),MARGIN_TOP,10,cxt);
?? ?renderDigit( MARGIN_LEFT + 39*(RADIUS+1) , MARGIN_TOP , parseInt(minutes/10) , cxt);
??? renderDigit( MARGIN_LEFT + 54*(RADIUS+1) , MARGIN_TOP , parseInt(minutes%10) , cxt);
??? renderDigit( MARGIN_LEFT + 69*(RADIUS+1) , MARGIN_TOP , 10 , cxt);
??? renderDigit( MARGIN_LEFT + 78*(RADIUS+1) , MARGIN_TOP , parseInt(seconds/10) , cxt);
??? renderDigit( MARGIN_LEFT + 93*(RADIUS+1) , MARGIN_TOP , parseInt(seconds%10) , cxt);
}
function renderDigit(x,y,num,cxt){
?? ?cxt.fillStyle="rgb(0,102,153)";
?? ?for(var i=0;i<digit[num].length;i++)
?? ??? ?for(var j=0;j<digit[num][i].length;j++)
?? ??? ?if(digit[num][i][j]==1){
?? ??? ??? ?cxt.beginPath();
?? ??? ??? ?cxt.arc(x+j*2*(RADIUS+1)+(RADIUS+1),y+i*2*(RADIUS+1)+(RADIUS+1),RADIUS,0,2*Math.PI)
?? ??? ??? ?cxt.closePath()
}
?? ??? ??? ?cxt.fill()
?? ??? ?}
}
2017-09-24
我代碼看了好久 沒(méi)發(fā)現(xiàn)錯(cuò)誤,然后我去改了我HTML中的本來(lái)我的設(shè)置是這樣的
<canvas id="canvas" style="border: 1px soild blue;display:block; margin: 0 auto;"></canvas>
開(kāi)始我不行的時(shí)候 可是會(huì)出現(xiàn)canvas 的繪圖框 ,然后我刪了canvas 下面的 style 就會(huì)顯示數(shù)字 1 了,然后我再添加 style 就可以了 ,這個(gè)是什么原因