android - 什么是 SystemClock.elapsedRealtime - 毫秒？

Question

我对我从给出的一些答案中检索到的一段代码有一些疑问，这些代码用于避免用户多次单击同一个按钮。有人可以向我解释这部分代码的作用和示例吗？

代码是

private long mLastClickTime = 0;

//Avoid the user clicking more than one
                if (SystemClock.elapsedRealtime() - mLastClickTime < 1000){
                    return;
                }
                mLastClickTime = SystemClock.elapsedRealtime();

if 条件放在每个按钮下面。setonclicklistener

我只是想明白这段代码只是做了什么:)

Answer 1

我会用更详细的变量名来解释它。

private long mLastClickTime = 0;
private long theUserCannotClickTime = 1000; // milliseconds. the time that must pass before the user's click become valid


long currentTime = SystemClock.elapsedRealtime(); // not necessarily the current realworld time, and it doesn't matter. You can even use System.currentTimeMillis()
long elapsedTime = currentTime - mLastClickTime; // the time that passed after the last time the user clicked the button

if (elapsedTime < theUserCannotClickTime)
    return; // 1000 milliseconds hasn't passed yet. ignore the click
}
// over 1000 milliseconds has passed. do something with the click

// record the time the user last clicked the button validly
mLastClickTime = currentTime;