一:
1.鼠標監視坐標值
1 <!DOCTYPE html> 2 <head> 3 <meta charset=UTF-8> 4 <title>canvas的演示</title> 5 <script src="D:\jquery\jquery-1.12.4.min.js""></script> 6 </head> 7 <body> 8 <canvas id="tt" width="100" height="100" onmousemove="mousexy(event)">不支持H5</canvas> 9 <div id="xy"></div> 10 11 <script type="text/javascript"> 12 var c=document.getElementById("tt"); 13 var tt=c.getContext("2d"); 14 15 function mousexy(n){ 16 x=n.clientX; 17 y=n.clientY; 18 document.getElementById("xy").innerHTML="x:"+x+"y:"+y; 19 } 20 </script> 21 </body> 22 </html>
2.運行結果
3.畫矩形
兩種方式:
其中,rgb支持透明度,0.5是透明度為0.5,所以可以看到底下的另一個矩形的顏色
1 <!DOCTYPE html> 2 <head> 3 <meta charset=UTF-8> 4 <title>canvas的演示</title> 5 <script src="D:\jquery\jquery-1.12.4.min.js""></script> 6 </head> 7 <body> 8 <canvas id="tt" width="400" height="400" onmousemove="mousexy(event)">不支持H5</canvas> 9 10 <script type="text/javascript"> 11 var c=document.getElementById("tt"); 12 var tt=c.getContext("2d"); 13 //yi 14 tt.fillStyle="red"; 15 tt.fillRect(0,0,200,200); 16 //er 17 tt.fillStyle="rgba(0,0,255,0.5)"; 18 tt.fillRect(100,100,300,300) 19 </script> 20 </body> 21 </html>
4.運行結果
5.畫線
1 <!DOCTYPE html> 2 <head> 3 <meta charset=UTF-8> 4 <title>canvas的演示</title> 5 <script src="D:\jquery\jquery-1.12.4.min.js""></script> 6 </head> 7 <body> 8 <canvas id="tt" width="300" height="300" onmousemove="mousexy(event)">不支持H5</canvas> 9 10 <script type="text/javascript"> 11 var c=document.getElementById("tt"); 12 var tt=c.getContext("2d"); 13 14 //line 15 tt.moveTo(30,30); 16 tt.lineTo(80,290); 17 tt.lineTo(130,10); 18 tt.stroke(); 19 20 </script> 21 </body> 22 </html>
6.運行結果
7.畫圓
1 <!DOCTYPE html> 2 <head> 3 <meta charset=utf-8> 4 <title>canvas的演示</title> 5 <script src="D:\jquery\jquery-1.12.4.min.js""></script> 6 </head> 7 <body> 8 <canvas id="tt" width="300" height="300">不支持H5</canvas> 9 10 <script type="text/javascript"> 11 var c=document.getElementById("tt"); 12 var tt=c.getContext("2d"); 13 14 tt.fillStyle="blue"; 15 tt.beginPath(); 16 tt.arc(100,100,50,0,Math.PI*2,true); 17 tt.closePath(); 18 tt.fill(); 19 </script> 20 </body> 21 </html>
8.運行結果
9.漸近色
1 <!DOCTYPE html> 2 <head> 3 <meta charset=UTF-8> 4 <title>canvas的演示</title> 5 <script src="D:\jquery\jquery-1.12.4.min.js""></script> 6 </head> 7 <body> 8 <canvas id="tt" width="400" height="400">不支持H5</canvas> 9 10 <script type="text/javascript"> 11 var c=document.getElementById("tt"); 12 var tt=c.getContext("2d"); 13 14 // 15 var change=tt.createLinearGradient(100,100,200,50); 16 change.addColorStop(0,"yellow"); 17 change.addColorStop(1,"blue"); 18 tt.fillStyle=change; 19 tt.fillRect(100,100,200,50); 20 21 </script> 22 </body> 23 </html>
10.運行效果
11.圖形載入
目前在谷歌瀏覽器上不可以展示,圖中使用的是I瀏覽器
1 <!DOCTYPE html> 2 <head> 3 <meta charset=UTF-8> 4 <title>canvas的演示</title> 5 <script src="D:\jquery\jquery-1.12.4.min.js""></script> 6 </head> 7 <body> 8 <canvas id="tt" width="400" height="400">不支持H5</canvas> 9 10 <script type="text/javascript"> 11 var c=document.getElementById("tt"); 12 var tt=c.getContext("2d"); 13 14 // 15 var img=new Image(); 16 img.src="logo.png"; 17 tt.drawImage(img,100,100); 18 19 </script> 20 </body> 21 </html>
12.運行效果