android 变量不在循环内递增

Question

我正在尝试编写一个简单的 android 程序，它将按照以下格式将歌词打印到墙上的 99 瓶啤酒。

第 1 行：99 瓶啤酒在墙上...

第 2 行：98 瓶啤酒在墙上...

等等。

我正在尝试创建一个循环来打印第一行歌词，然后 increment/decrement 变量 "lineNumber"、"numOfBottles" 和 "lessNumOfBottles"。

我尝试了几种不同的方法和运算符，但我的变量在编译时从未改变，而且我在每一行歌词中得到相同的重复数字。

我做错了什么？（评论中的底部循环是我尝试的第一个，我只留下它作为自己的参考）

protected void onResume(){
    super.onResume();


    int lineNumber = 1;
    int numOfBottles = 99;
    int lessNumOfBottles = 98;
    String line = "Line " + lineNumber + ":\n";
    String lyrics= "Lyrics to 99 bottles of beer \n\n";
    String song =line +  numOfBottles + " bottles of beer on the wall," + numOfBottles + " bottles of beer, take one down, pass it around," + lessNumOfBottles + " bottles of beer on the wall.\n\n";


    TextView textview = (TextView) findViewById(R.id.myTextView);

    textview.setText(lyrics);

    for(int i = 99;i >= 1;i--) {
        if (numOfBottles >= 1) {
            textview.append(song);
            --numOfBottles;
            --lessNumOfBottles;
            ++lineNumber;
        }
    }

    /*for (int i=0;i<99;){
        lineNumber++;
        numOfBottles= --numOfBottles;
        lessNumOfBottles= --lessNumOfBottles;
        textview.setText(song);
        textview.append(song);
        i++;
    }*/
}

Answer 1

您仅将字符串的值分配给 lineNumber、numOfBottles 和 lessNumOfBottles 的第一个值一次。 line 和 song 变量永远不会更新。

试试这个：

protected void onResume(){
    super.onResume();


    int numLines = 100;
    int numOfBottles = 99;
    String line;
    String lyrics= "Lyrics to 99 bottles of beer \n\n";

    TextView textview = (TextView) findViewById(R.id.myTextView);

    textview.setText(lyrics);

    for(int i = numOfBottles;i >= 1;i--) {
        if (numOfBottles >= 1) {
            line = "Line " + numLines-i + ":\n";
            textview.append(line + i + " bottles of beer on the wall," + 
                             i + " bottles of beer, take one down, pass it around," + 
                             i-1 + " bottles of beer on the wall.\n\n");
        }
    }
}

android 变量不在循环内递增

android variables not incrementing inside loop

java

android

loops

increment

operators