修改了签名板和关联选项设置不兼容的bug

src/widget/writingboard/vueSignature.vue

@@ -102,8 +102,10 @@
   const getSizeRatio = () => {
     return !props.fullScreen && props.backIsCenter
   }
-  const setCanvasImageBack = (status: any) => {
+  const setCanvasImageBack = (status: any,canvas:any) => {
-    const canvas = canvasRef.value as HTMLCanvasElement
+    //const canvas = canvasRef.value as HTMLCanvasElement
+    //console.log(canvas)
+    if(typeof(canvas)!="undefined"&&typeof(canvas.width)!="undefined"){
       let pat = canvasTxt.value?.createPattern(canvasBackDom.value, (props.isRepeat || "no-repeat"));
       canvasTxt.value?.rect(0,0,canvas.width ,canvas.height)
       canvasTxt!.value!.fillStyle = (pat as any); 
@@ -112,10 +114,12 @@
           autoDraw(null, null)
       }
     }
-  const setCanvasBack = (status: any) => {
+    
-     const canvas = canvasRef.value as HTMLCanvasElement
+  }
+  const setCanvasBack = (status: any,canvas:any) => {
+     //const canvas = canvasRef.value as HTMLCanvasElement
      if (props.canvasBack && canvasBackDom.value && isImgaes(props.canvasBack)) {
-      setCanvasImageBack(status)
+      setCanvasImageBack(status,canvas)//liwenxuan
       } else {
         canvas.style.background = canvasBackground.value
       }
@@ -145,12 +149,19 @@
       canvasTxt.value?.scale(1 * sratio.value, 1 * sratio.value)
       sratio.value = realw / (domPatams.width ? domPatams.width : props.fullScreen ? screenPatams.width : props.width)
       canvasTxt.value?.scale(1 / sratio.value, 1 / sratio.value)
+      
       if (props.canvasBack) {
         let IntervaId = setInterval(() => {
+          //console.log("111111111111111111111111111111111111111111111111111111")
+          //console.log(canvas)
+          if(typeof(canvas)!="undefined"){
+            console.log(canvas)
             if ((canvasBackDom.value && isLoad.value) || !isImgaes(props.canvasBack)) {
-            setCanvasBack(status)
+              setCanvasBack(status,canvas)//liwenxuan
               clearInterval(IntervaId)
             }
+          }
+          
         }, 100)
       } else {
         if (status) {