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如何在onClickListener事件上第一次计算变量的值?

onclicklistener android-asynctask android java

Saeed · 技术社区 · 7 年前

private long checkOffCode(String pChode) {
    final long[] percent = {0};
    APIGettingPosts apiGettingPosts = new APIGettingPosts(MainActivity.this, "get_off_code.php");
    apiGettingPosts.getOffCode(new APIGettingPosts.OnOffCodeReceived() {
        @Override
        public void onReceived(List<Posts> posts) {
            if (posts == null || posts.isEmpty()) {
                // There is no value on sever...
            } else {
                for (int i = 0; i < posts.size(); ++i) {

                    // If the code in serve is equal with pCode],
                    // change the price value....

                    if (pChode.equals(posts.get(i).getCode())) {
                        percent[0] = Long.valueOf(posts.get(i).getPercent());
                    }
                }
            }
        }
    });

    return percent[0];
}

这个 checkOffCode 函数接收一个代码,并返回一个名为 percent

在事件中 setOnClickListener btnPurchase price 本节代码如下:

btnPurchase.setOnClickListener(new View.OnClickListener(){
    long percent = 0;
    @Override
    public void onClick (View view){

    percent = checkOffCode("MYCODE");
    if (percent != 0) {
        // update price value...
        price = price - price * percent / 100;
        Log.e("Success >>", String.valueOf(price));
    } else {
        Log.e("Failure >>", String.valueOf(price));
    }
}
});

问题是当我点击 BTN采购 第一次按下按钮,前一个值 百分比 [percent=0]是在操作中计算出来的,但是当我第二次单击按钮时,变量 价格 百分比

输出 Log cat 在第一次和第二次单击中分别显示如下:

如何计算 价格 用新的第一次的价值?

2 回复 | 直到 7 年前

orzangleli 7 年前

问题是您试图从 checkOffCode onReceived

private void checkOffCode(String pChode) {
    final long[] percent = {0};
    APIGettingPosts apiGettingPosts = new APIGettingPosts(MainActivity.this, "get_off_code.php");
    apiGettingPosts.getOffCode(new APIGettingPosts.OnOffCodeReceived() {
        @Override
        public void onReceived(List<Posts> posts) {
            if (posts == null || posts.isEmpty()) {
                // There is no value on sever...
            } else {
                for (int i = 0; i < posts.size(); ++i) {

                    // If the code in serve is equal with pCode],
                    // change the price value....

                    if (pChode.equals(posts.get(i).getCode())) {
                        percent[0] = Long.valueOf(posts.get(i).getPercent());
                    }
                }
            }
            if (percent[0] != 0) {
                // update price value...
                price = price - price * percent[0] / 100;
                Log.e("Success >>", String.valueOf(price));
            } else {
                Log.e("Failure >>", String.valueOf(price));
            }
        }
    });
}

btnPurchase.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        checkOffCode("MYCODE");
    }
});

Tepits 7 年前

您可以尝试添加布尔值,如果第一次单击,则计算价格,因此如果第二次再次单击,则不会触发计算。例如:

首先在onClick函数外生成布尔变量:

private Boolean isFirstClicked = false;

然后修改onClick函数:

if (!isFirstClicked) {
    // update price value...
    isFirstClicked = true
    price = price - price * percent / 100;
    Log.e("Success >>", String.valueOf(price));
} else {
    Log.e("Failure >>", String.valueOf(price));
}