Question

我正在使用Appcelerator开发Android设备。由于我需要画一些线，我在我的项目中下载并安装了“com.wwl.canvas”模块。当我在我的项目上尝试app.js示例时，一切正常......无论如何，当我编写这段代码时：

var Canvas = require('com.wwl.canvas');
var canvas = Canvas.createCanvasView({
        backgroundColor: "transparent",
        right: "20dp",
        bottom: "80dp",
        top: "20dp",
        left: "20dp",
        zIndex: 10
    });

overlay.add(canvas);

var shapes = [
    {
        name: 'polygon',

        fn: function(){
            canvas.beginPath();
            canvas.lineWidth = 7;
            canvas.strokeStyle = 'blue';
            canvas.drawLine(0,0,400,400);
            canvas.drawLine(400,400,400,300);
            canvas.drawLine(400,300,800,300);
            canvas.drawLine(800,300,700,200);
            canvas.drawLine(700,200,0,0);
        }
    } 

    ];

shapes[0].fn();

它说：“在空对象引用上尝试从字段'com.wwl.canvas.CanvasView $ CView com.wwl.canvas.CanvasView.cView'读取在com.wwl.canvas.CanvasViewProxy.beginPath（CanvasViewProxy.java:109） ......“

任何人都可以帮助我吗？

com.wwl.canvas - 尝试从空对象上的字段读取

0 个答案: