android变量不会在循环内递增

Question

我正在尝试编写一个简单的 android 程序，它将按以下格式将 99 瓶啤酒的歌词打印在墙上。

第 1 行：墙上有 99 瓶啤酒……

第 2 行：墙上有 98 瓶啤酒……

等等。

我正在尝试创建一个循环来打印第一行歌词，然后递增/递减变量“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，而且每行歌词都得到相同的重复数字。

我做错了什么？ （cmets 中的底部循环是我尝试过的第一个循环，我只是将其作为自己的参考）

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

您只将字符串的值分配给lineNumber、numOfBottles 和lessNumOfBottles 的第一个值。 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");
        }
    }
}