如何对对象的 ArrayList 进行排序（玩家姓名和玩家分数）答案

【问题标题】：How to sort an ArrayList of Objects (Player Names and Player Scores)如何对对象的 ArrayList 进行排序（玩家姓名和玩家分数）
【发布时间】：2017-06-13 14:05:16
【问题描述】：

我尝试解决这个问题，但我不知道我做错了什么，已经过了 7 天尝试了很多事情，我需要帮助解决它，我认为错误出在我创建的类上。

我有 4 个玩家，有 4 个文本视图和 4 个其他文本视图用于玩家的得分。此外，我还为 place1、place2、place3、place4 制作了另外 4 个新的文本视图。我想要做的是，我需要对分数进行排序并将它们显示在 place1、place2、place3、place4 以及拥有该分数的玩家的姓名。

到目前为止，我所做的是将我的类创建到 onCreate 部分上方的主要活动中

public class MainActivity extends AppCompatActivity {

    //my created class
    class JucatorScor {

        public String Name;
        public int Scor;

        public JucatorScor (String sName, int iScor) {
            this.Name = sName;
            this.Scor = iScor;
        }
    }

    //begin oncreate
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    //end oncreate
}

我还有一个按钮，当我点击它时，从文本视图中读取我的值，查看球员姓名、球员得分，然后对数组进行排序后显示 place1、place2、place3、place4，如下所示：

//begin button click
public void sorteazaCLICK (View view) {

    //initialization place1, place2, place3, place4 where i will put the sorting value
    TextView varPozitia1 = (TextView) findViewById(R.id.text_loc1);
    TextView varPozitia2 = (TextView) findViewById(R.id.text_loc2);
    TextView varPozitia3 = (TextView) findViewById(R.id.text_loc3);
    TextView varPozitia4 = (TextView) findViewById(R.id.text_loc4);

    //initialization name of players
    TextView varNumeJucator1 = (TextView) findViewById(R.id.text_numeJuc1);
    String sNameJuc1;
    sNameJuc1 = varNumeJucator1.getText().toString();

    TextView varNumeJucator2 = (TextView) findViewById(R.id.text_numeJuc2);
    String sNameJuc2;
    sNameJuc2 = varNumeJucator1.getText().toString();

    TextView varNumeJucator3 = (TextView) findViewById(R.id.text_numeJuc3);
    String sNameJuc3;
    sNameJuc3 = varNumeJucator1.getText().toString();

    TextView varNumeJucator4 = (TextView) findViewById(R.id.text_numeJuc4);
    String sNameJuc4;
    sNameJuc4 = varNumeJucator1.getText().toString();

    //initialization scores
    TextView varScorJucator1 = (TextView) findViewById(R.id.text_scorJuc1);
    String t1;
    t1 = varScorJucator1.getText().toString();

    TextView varScorJucator2 = (TextView) findViewById(R.id.text_scorJuc2);
    String t2;
    t2 = varScorJucator2.getText().toString();

    TextView varScorJucator3 = (TextView) findViewById(R.id.text_scorJuc3);
    String t3;
    t3 = varScorJucator1.getText().toString();

    TextView varScorJucator4 = (TextView) findViewById(R.id.text_scorJuc4);
    String t4;
    t4 = varScorJucator1.getText().toString();


    //transform the values from text view scores into integer
    int iScorJuc1;
    iScorJuc1 = Integer.parseInt(t1);

    int iScorJuc2;
    iScorJuc2 = Integer.parseInt(t2);

    int iScorJuc3;
    iScorJuc3 = Integer.parseInt(t3);

    int iScorJuc4;
    iScorJuc4 = Integer.parseInt(t4);


    ArrayList<JucatorScor> arrJucatorScor = new ArrayList<>(4);


        //building manually the array list
        arrJucatorScor.add(new JucatorScor(sNameJuc1, iScorJuc1));  //position 0
        arrJucatorScor.add(new JucatorScor(sNameJuc2, iScorJuc2));  //position 1
        arrJucatorScor.add(new JucatorScor(sNameJuc3, iScorJuc3));  //position 2
        arrJucatorScor.add(new JucatorScor(sNameJuc4, iScorJuc4));  //position 3

    Collections.sort(arrJucatorScor, new Comparator<JucatorScor>() {

        //sorting my object array depending on scores
        @Override
        public int compare(JucatorScor o1, JucatorScor o2) {
            return Integer.valueOf(o1.Scor).compareTo(o2.Scor);
        }

    });


    //here display them from bigger to smaller according to eatch place1, place2, place3, place4
    varPozitia1.setText(String.valueOf(arrJucatorScor.get(3)));
    varPozitia2.setText(String.valueOf(arrJucatorScor.get(2)));
    varPozitia3.setText(String.valueOf(arrJucatorScor.get(1)));
    varPozitia4.setText(String.valueOf(arrJucatorScor.get(0)));

} //end button click

问题是，当我点击按钮时，不要把 place1、place2、place3、place4 的名称和分数排序...只是出现在这张照片中的一些东西：

【问题讨论】：

标签： java android arrays sorting

【解决方案1】：

这里你使用JucatorScor的toString()方法来渲染对象：

varPozitia1.setText(String.valueOf(arrJucatorScor.get(3)));
varPozitia2.setText(String.valueOf(arrJucatorScor.get(2)));
varPozitia3.setText(String.valueOf(arrJucatorScor.get(1)));
varPozitia4.setText(String.valueOf(arrJucatorScor.get(0)));

您在屏幕上看到的是基类提供的默认实现toString()。

你要么用想要的文本实现toString()

或者另一种解决方案是在辅助方法中执行渲染，并在TextView 中设置合适的String：

public set renderTopJucatorScor(JucatorScor jucatorScor, int ranking, TextView varPozitia){    
    varPozitia.setText("Loc" + ranking +  " = " + jucatorScor.getName() + jucatorScor.getScore());
}

然后你可以像这样调用辅助方法：

renderTopJucatorScor(varPozitia1, arrJucatorScor.get(3), 1);
renderTopJucatorScor(varPozitia2, arrJucatorScor.get(2), 2);
renderTopJucatorScor(varPozitia3, arrJucatorScor.get(1), 3);
renderTopJucatorScor(varPozitia4, arrJucatorScor.get(0), 4);

【讨论】：

非常感谢您的回答...但是...我不明白..您可以用代码举例吗？我试着把这个放在我的课上 @Override public String toString() { return Name + " " + Scor; } 但没有正确显示结果:((
不客气。如果在 JucatorScor 类中添加 toString() 方法，它应该可以工作。您是否注意到渲染的任何变化？如果你什么也没看到，可能编译的代码没有更新。
我创建的类现在看起来像这样 class JucatorScor { public String Name;公共 int 得分；公共 JucatorScor (String sName, int iScor) { this.Name = sName; this.Scor = iScor; } @Override public String toString() { return Name + " " + Scor;这是我只在课堂上所做的所有更改，当我运行应用程序时。显示结果如下所示 Place1 = Aladin 550 Place2 = Aladin 120 Place3 = Aladin 120 Place4 = Aladin 120
你在初始代码中想要获取第三个和第四个textView的分数时出现了不注意的错误。您仍然使用 varScorJucator1 代替 varScorJucator3 和 varScorJucator4：TextView varScorJucator3 = (TextView) findViewById(R.id.text_scorJuc3); String t3; t3 = varScorJucator1.getText().toString(); TextView varScorJucator4 = (TextView) findViewById(R.id.text_scorJuc4); String t4; t4 = varScorJucator1.getText().toString();T
结局很开心 :) 为避免此类问题，您应该像我在回答中所做的那样支持使用辅助方法，而不是进行简单但也会带来风险的复制/粘贴重用坏变量。例如，获取每个 textview 分数的三个指令可以在返回 String 的辅助方法中。

【解决方案2】：

在发现（在用户“davidxxx”的帮助下）我的 textviews 初始化中出现了一些错误，最终我设法解决了这个问题。我还在我创建的类中添加了一个方法：toString。

正确的解决办法是这样的：

//my created class
class JucatorScor {

    public String Name;
    public int Scor;

    public JucatorScor (String sName, int iScor) {
        this.Name = sName;
        this.Scor = iScor;
    }
//this is the toString added to diplay name and score 
    @Override
    public String toString() {
        return Name + " " + Scor;
    }

}

以及按钮点击的执行代码

//begin button click
public void sorteazaCLICK(View view) {

    //initialization of textvies for place1 to place 4
    TextView varPozitia1 = (TextView) findViewById(R.id.text_loc1);
    TextView varPozitia2 = (TextView) findViewById(R.id.text_loc2);
    TextView varPozitia3 = (TextView) findViewById(R.id.text_loc3);
    TextView varPozitia4 = (TextView) findViewById(R.id.text_loc4);

    //initialization for name of players
    TextView varNumeJucator1 = (TextView) findViewById(R.id.text_numeJuc1);
    String sNameJuc1;
    sNameJuc1 = varNumeJucator1.getText().toString();

    TextView varNumeJucator2 = (TextView) findViewById(R.id.text_numeJuc2);
    String sNameJuc2;
    sNameJuc2 = varNumeJucator2.getText().toString();

    TextView varNumeJucator3 = (TextView) findViewById(R.id.text_numeJuc3);
    String sNameJuc3;
    sNameJuc3 = varNumeJucator3.getText().toString();

    TextView varNumeJucator4 = (TextView) findViewById(R.id.text_numeJuc4);
    String sNameJuc4;
    sNameJuc4 = varNumeJucator4.getText().toString();

    //initialization of scores
    TextView varScorJucator1 = (TextView) findViewById(R.id.text_scorJuc1);
    String t1;
    t1 = varScorJucator1.getText().toString();

    TextView varScorJucator2 = (TextView) findViewById(R.id.text_scorJuc2);
    String t2;
    t2 = varScorJucator2.getText().toString();

    TextView varScorJucator3 = (TextView) findViewById(R.id.text_scorJuc3);
    String t3;
    t3 = varScorJucator3.getText().toString();

    TextView varScorJucator4 = (TextView) findViewById(R.id.text_scorJuc4);
    String t4;
    t4 = varScorJucator4.getText().toString();


    //transformation scores into integer values
    int iScorJuc1;
    iScorJuc1 = Integer.parseInt(t1);

    int iScorJuc2;
    iScorJuc2 = Integer.parseInt(t2);

    int iScorJuc3;
    iScorJuc3 = Integer.parseInt(t3);

    int iScorJuc4;
    iScorJuc4 = Integer.parseInt(t4);


    ArrayList<JucatorScor> arrJucatorScor = new ArrayList<>(4);


    //manually construct of the object array list
    arrJucatorScor.add(new JucatorScor(sNameJuc1, iScorJuc1));  //position 0
    arrJucatorScor.add(new JucatorScor(sNameJuc2, iScorJuc2));  //position 1
    arrJucatorScor.add(new JucatorScor(sNameJuc3, iScorJuc3));  //position 2
    arrJucatorScor.add(new JucatorScor(sNameJuc4, iScorJuc4));  //position 3

    Collections.sort(arrJucatorScor, new Comparator<JucatorScor>() {

        //the sort of the object list by their scores
        @Override
        public int compare(JucatorScor o1, JucatorScor o2) {
            return Integer.valueOf(o1.Scor).compareTo(o2.Scor);
        }

    });


    //here are displayed in the position place1 to place4 from bigger score to smaller score
    varPozitia1.setText(String.valueOf(arrJucatorScor.get(3)));
    varPozitia2.setText(String.valueOf(arrJucatorScor.get(2)));
    varPozitia3.setText(String.valueOf(arrJucatorScor.get(1)));
    varPozitia4.setText(String.valueOf(arrJucatorScor.get(0)));


}//end button click

非常感谢您的帮助。

【讨论】：