我有一种情况，我想获得一个列表（按钮点击）列出的4个玩家的分数（新活动）（1.名称 - 得分2.名称 - 得分等）从高分到低分。以下是我在Activity中的代码，其中我将姓名和分数发送到活动2。
Button calculate4 = (Button) findViewById(R.id.calculate4);
calculate4.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent myIntent = new Intent(view.getContext(), FourCalculate.class);
myIntent.putExtra("name1", name1.getText().toString());
myIntent.putExtra("name2", name2.getText().toString());
myIntent.putExtra("name3", name3.getText().toString());
myIntent.putExtra("name4", name4.getText().toString());
myIntent.putExtra("p1", p1.getText().toString());
myIntent.putExtra("p2", p2.getText().toString());
myIntent.putExtra("p3", p3.getText().toString());
myIntent.putExtra("p4", p4.getText().toString());
startActivity(myIntent);
}
});
这是我在活动2中的代码：
public class FourCalculate extends Activity {
class Calculate {
public String Name;
public int Scor;
public Calculate(String sName, int iScor) {
this.Name = sName;
this.Scor = iScor;
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_four_calculate);
// Names
TextView place1final = (TextView) findViewById(R.id.place1);
place1final.setText(getIntent().getExtras().getString("name1"));
String name1final;
name1final = place1final.getText().toString();
TextView place2final = (TextView) findViewById(R.id.place2);
place2final.setText(getIntent().getExtras().getString("name2"));
String name2final;
name2final = place2final.getText().toString();
TextView place3final = (TextView) findViewById(R.id.place3);
place3final.setText(getIntent().getExtras().getString("name3"));
String name3final;
name3final = place3final.getText().toString();
TextView place4final = (TextView) findViewById(R.id.place4);
place4final.setText(getIntent().getExtras().getString("name4"));
String name4final;
name4final = place4final.getText().toString();
// Scores
TextView place1finalscore = (TextView) findViewById(R.id.place1score);
place1finalscore.setText(getIntent().getExtras().getString("p1"));
String score1final;
score1final = place1finalscore.getText().toString();
TextView place2finalscore = (TextView) findViewById(R.id.place2score);
place1finalscore.setText(getIntent().getExtras().getString("p2"));
String score2final;
score2final = place2finalscore.getText().toString();
TextView place3finalscore = (TextView) findViewById(R.id.place3score);
place3finalscore.setText(getIntent().getExtras().getString("p3"));
String score3final;
score3final = place3finalscore.getText().toString();
TextView place4finalscore = (TextView) findViewById(R.id.place4score);
place4finalscore.setText(getIntent().getExtras().getString("p4"));
String score4final;
score4final = place4finalscore.getText().toString();
int finalscore1;
finalscore1 = Integer.parseInt(score1final);
int finalscore2;
finalscore2 = Integer.parseInt(score2final);
int finalscore3;
finalscore3 = Integer.parseInt(score3final);
int finalscore4;
finalscore4 = Integer.parseInt(score4final);
ArrayList<FourCalculate> arrFourCalculate = new ArrayList<>(4);
//building manually the array list
arrFourCalculate.add(new Calculate(name1final, finalscore1));
arrFourCalculate.add(new Calculate(name2final, finalscore2));
arrFourCalculate.add(new Calculate(name3final, finalscore3));
arrFourCalculate.add(new Calculate(name4final, finalscore4));
Collections.sort(arrFourCalculate, new Comparator<FourCalculate>() {
@Override
public int compare(FourCalculate o1, FourCalculate o2) {
return Integer.valueOf(o1.Scor).compareTo(o2.Scor);
}
});
place1final.setText(String.valueOf(arrFourCalculate.get(3)));
place2final.setText(String.valueOf(arrFourCalculate.get(2)));
place3final.setText(String.valueOf(arrFourCalculate.get(1)));
place4final.setText(String.valueOf(arrFourCalculate.get(0)));
}
}
输入姓名和号码后，当我尝试访问活动2时，应用程序崩溃。 logcat的：
07-23 18:32:26.416 12392-12392/com.example.sante.myapplication E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.sante.myapplication, PID: 12392
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.sante.myapplication/com.example.sante.myapplication.FourCalculate}: java.lang.NumberFormatException: For input string: ""
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6119)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
Caused by: java.lang.NumberFormatException: For input string: ""
at java.lang.Integer.parseInt(Integer.java:533)
at java.lang.Integer.parseInt(Integer.java:556)
at com.example.sante.myapplication.FourCalculate.onCreate(FourCalculate.java:79)
at android.app.Activity.performCreate(Activity.java:6679)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2618)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6119)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
答案 0 :(得分：0)
你的错误似乎很明显，这里发生了什么。你 不能 实例化一个活动，所以这个：
public FourCalculate (String sName, int iScor) {
this.Name = sName;
this.Scor = iScor;
}
和此：
arrFourCalculate.add(new FourCalculate(name1final, finalscore1));
arrFourCalculate.add(new FourCalculate(name2final, finalscore2));
arrFourCalculate.add(new FourCalculate(name3final, finalscore3));
arrFourCalculate.add(new FourCalculate(name4final, finalscore4));
无法完成。为对象创建单独的模型类
答案 1 :(得分：0)
Finaly！在一些帮助下，我实现了我想要的。分享正确的代码。
public class FourCalculate extends Activity {
class Calculate {
public String Name;
public int Scor;
public Calculate(String sName, int iScor) {
this.Name = sName;
this.Scor = iScor;
}
@Override
public String toString() {
return Name + " " + Scor;
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_four_calculate);
// Names
TextView place1final = (TextView) findViewById(R.id.place1);
place1final.setText(getIntent().getExtras().getString("name1"));
String name1final;
name1final = place1final.getText().toString();
TextView place2final = (TextView) findViewById(R.id.place2);
place2final.setText(getIntent().getExtras().getString("name2"));
String name2final;
name2final = place2final.getText().toString();
TextView place3final = (TextView) findViewById(R.id.place3);
place3final.setText(getIntent().getExtras().getString("name3"));
String name3final;
name3final = place3final.getText().toString();
TextView place4final = (TextView) findViewById(R.id.place4);
place4final.setText(getIntent().getExtras().getString("name4"));
String name4final;
name4final = place4final.getText().toString();
String finalscore1 = getIntent().getExtras().getString("p1");
String finalscore2 = getIntent().getExtras().getString("p2");
String finalscore3 = getIntent().getExtras().getString("p3");
String finalscore4 = getIntent().getExtras().getString("p4");
finalscore1 = finalscore1.length() > 0 ? finalscore1 : "0";
finalscore2 = finalscore2.length() > 0 ? finalscore2 : "0";
finalscore3 = finalscore3.length() > 0 ? finalscore3 : "0";
finalscore4 = finalscore4.length() > 0 ? finalscore4 : "0";
ArrayList<Calculate> arrFourCalculate = new ArrayList<>(4);
arrFourCalculate.add(new Calculate(name1final, Integer.parseInt(finalscore1)));
arrFourCalculate.add(new Calculate(name2final, Integer.parseInt(finalscore2)));
arrFourCalculate.add(new Calculate(name3final, Integer.parseInt(finalscore3)));
arrFourCalculate.add(new Calculate(name4final, Integer.parseInt(finalscore4)));
Collections.sort(arrFourCalculate, new Comparator<Calculate>() {
@Override
public int compare(Calculate o1, Calculate o2) {
return Integer.valueOf(o1.Scor).compareTo(o2.Scor);
}
});
place1final.setText(String.valueOf(arrFourCalculate.get(3)));
place2final.setText(String.valueOf(arrFourCalculate.get(2)));
place3final.setText(String.valueOf(arrFourCalculate.get(1)));
place4final.setText(String.valueOf(arrFourCalculate.get(0)));
}
}