如何从非活性类访问绘 [英] How to access drawable from non activity class

问题描述

我在一个情况下，我必须使用绘制文件夹我的应用程序的形成非活性类。我试着用父活动具有以下code：

I am in a situation where I have to use the drawable folder of my app form a non activity class. I tried using the parent activity with the following code:

ParentActivity pa = new ParentActivity();
Drawable d = pa.getResources()..getDrawable(R.drawable.icon);`

但是，这将返回我一个 NullPointerException异常。
我怎样才能做到这一点？

But this returns me a NulLPointerException. How can I achieve this?

推荐答案

传递上下文对象作为参数传递给非活动类的构造函数。

Pass the context object as a parameter to the constructor of the non Activity class.

然后使用上下文对象来获取资源。

Then use that context object to get the Resources.

示例

public class MyClass {
  Context context;
  public MyClass(Context context) {
      this.context = context;
  }

  public void urMethod() {
    Drawable drawable=context.getResources().getDrawable(R.drawable.icon);
    // use this drawable as u need
  }
}

这篇关于如何从非活性类访问绘的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！