kotlin无内存泄露的Handler写法

    private val handler : Handler = object : Handler() {
        override fun handleMessage(msg: Message) {
        }
    }

上面这种写法编译器会警告：‘constructor Handler()’ is deprecated. Deprecated in Java

    private val handler : Handler = object : Handler(Looper.myLooper()!!) {
        override fun handleMessage(msg: Message) {
        }
    }

注意上面要加!!这两个感叹号，代表是只有不为空时才执行，不加会报错：Type mismatch: inferred type is Looper? but Looper was expected

private class UIHandler(val mWeakRef: WeakReference) : Handler(Looper.myLooper()!!) {
        override fun handleMessage(msg: Message) {
            super.handleMessage(msg)
             // 注意这里加个.run，代表是跑在this中的，方便直接访问外部类，当然也可以不用run，
             // 但是所有访问外部类的地方都要用mWeakRef.get()->的形式，写起来麻烦点
            mWeakRef.get()?.run {
                when (msg.what) {
                	// xxxxxx
                }
            }
        }
    }
 
private val handler = UIHandler(WeakReference(this))

作者：帅得不敢出门