Question

I am currently using the following library: https://www.npmjs.com/package/vue-signature-pad which has the following example: https://codesandbox.io/s/n5qjp3oqv4

I am applying it as the example, but I have it in a modal:

<v-dialog v-model="canvasVehiculo" fullscreen hide-overlay transition="dialog-bottom-transition">
         <v-card>
         <v-toolbar dark color="primary">
         <v-btn icon dark @click="canvasVehiculo = false">
          <v-icon>close</v-icon>
         </v-btn>
         <v-toolbar-title>Seleccionar partes del vehiculo:</v-toolbar-title>
            <v-spacer></v-spacer>
            <v-toolbar-items>
            <v-btn dark flat @click="undo">Deshacer</v-btn>
          </v-toolbar-items>
        </v-toolbar>
        <v-list three-line subheader>
        <v-subheader></v-subheader>            
        <VueSignaturePad
         id="signature"
         width="100%"
         height="450px"
         ref="signaturePad"
        />
   </v-list>
 </v-card>

<script>
import VueSignature from 'vue-signature-pad'; //Unicamente lo importo
</script>
<style scoped>
#signature {
  border: double 3px transparent;
  border-radius: 5px;
  background-image: url('imagen.png');
  background-size: 900px 456px; 
  background-position: center;
  background-origin: border-box;
  background-clip: content-box, border-box;
}
</style>

If I use it outside of the modal, it works correctly; but in the modal, to make it work, I must modify the size of the screen (for example, by using the DevTools' Toggle device toolbar to see the responsive form).

Answer 1

打开DevTools并查看canvas元素。首先，您会看到其宽度和高度（不是宽度和高度样式）设置为0，然后调整窗口大小，您会看到宽度和高度被更改为某些值并且可以正常工作。

在VueSignaturePad.js。看一下resizeCanvas方法

canvas.width = canvas.offsetWidth * ratio;
canvas.height = canvas.offsetHeight * ratio;

在安装v-dialog之后再安装VueSignaturePad时。 resizeCanvas在mounted被调用一次，并且此时画布以某种方式没有宽度和高度（由于其父级），因此将这些值设置为0。调整窗口大小后，它将再次调用并更新这些值。

解决此问题的一种方法是在父项完成渲染后调用resizeCanvas。

this.$nextTick(() => {
  this.$refs.signaturePad.resizeCanvas();
})

请参见codesandbox。

注意：resizeCanvas不是官方方法。

Answer 2

由于对话框没有宽度和高度，这是由于画布在其中进行初始化时要解决的，您可以将resizeCanvas事件调用传递给组件的选项：

<VueSignaturePad
    id="signature"
    width="100%"
    height="200px"
    ref="signaturePad"
    :options="{onBegin: () => {$refs.signaturePad.resizeCanvas()}}"
/>

Why doesn't vue-signature-pad work in a modal?

2 个答案: