html5(2)

    canvas:  
    getContext('2d'):    
    stroRect(x,y,width,height):     ，      
    fillRect(x,y,width,height):      ，   
    clearRect(x,y,width,height):      
    fillStyle:     ，     
    strokeStyle:      ，   
    lineWidth:      ，   
    line='round'            
    line='bevel'            

      
    moveTo(x,y):   
    lineTo(x,y):   
    stroke():    
    fill():    
    beginPath():      
    closePath():    

      
    arc(x,y,  ，    ，    ，    )
    x,y    
      =  *Math.PI/180

    drawImage()         img,x,y
            img,x,y,width,height
            img,sx,sy,swidth,sheight,x,y,width,height
    createPattern()          img,    
    createLinearGradient(x,y,x2,y2)    
    createRadialGradient(x1,y1,r1,x2,y2,r2)      
    strokeText(  ，x，y，)     
    fillText(  ,x,y,)     
    font='     '
    textAlign      
    textBaseLine      
    measureText(  )     
    shadowOffsetX,shadowOffsetY     X Y   
    shadowBlur     
    shadowColor