Question

我想更改代码，以便每次单击“下一个数字”按钮时，它会生成一个随机数。生成最后一个号码时，应用程序将执行除最后一个号码之外的排序。生成最后一个数字后，单击该按钮将没有响应。您需要单击“清除”按钮才能重新启动。并没有出现重复。这是我的代码 MainActivity.java

public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

int Count=0;
public void generate(View v){
    Random myRandom = new Random();

    TextView tv_number_one = (TextView)findViewById(R.id.tv_number_one);
    TextView tv_number_two = (TextView)findViewById(R.id.tv_number_two);
    TextView tv_number_three = (TextView)findViewById(R.id.tv_number_three);
    TextView tv_number_four = (TextView)findViewById(R.id.tv_number_four);
    TextView tv_number_five = (TextView)findViewById(R.id.tv_number_five);
    TextView tv_number_six = (TextView)findViewById(R.id.tv_number_six);
    TextView tv_number_seven = (TextView)findViewById(R.id.tv_number_seven);
    String ran=String.valueOf(myRandom.nextInt(50));
    switch(Count%7){

        case 0:
            tv_number_one.setText(ran);
            break;

        case 1:
            tv_number_two.setText(ran);
            break;

        case 2:
            tv_number_three.setText(ran);
            break;

        case 3:
            tv_number_four.setText(ran);
            break;

        case 4:
            tv_number_five.setText(ran);
            break;

        case 5:
            tv_number_six.setText(ran);
            break;

        case 6:
            tv_number_seven.setText(ran);
            break;

    }
    Count++;
}
public void clear (View v){
TextView tv_number_one = (TextView)findViewById(R.id.tv_number_one);
TextView tv_number_two = (TextView)findViewById(R.id.tv_number_two);
TextView tv_number_three = (TextView)findViewById(R.id.tv_number_three);
TextView tv_number_four = (TextView)findViewById(R.id.tv_number_four);
TextView tv_number_five = (TextView)findViewById(R.id.tv_number_five);
TextView tv_number_six = (TextView)findViewById(R.id.tv_number_six);
TextView tv_number_seven = (TextView)findViewById(R.id.tv_number_seven);

tv_number_one.setText("?");
tv_number_two.setText("?");
tv_number_three.setText("?");
tv_number_four.setText("?");
tv_number_five.setText("?");
tv_number_six.setText("?");
tv_number_seven.setText("?");

}

}

activity_main

<TextView android:text="\?" android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/tv_number_one"
    android:textSize="30sp"
    android:textIsSelectable="true"
    android:layout_marginLeft="10dp"
    android:textColor="#67ceff"
    android:layout_marginStart="20dp"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="\?"
    android:id="@+id/tv_number_two"
    android:layout_alignBottom="@+id/tv_number_one"
    android:layout_toRightOf="@+id/tv_number_one"
    android:layout_toEndOf="@+id/tv_number_one"
    android:textColor="#67ceff"
    android:textSize="30sp"
    android:layout_marginLeft="20dp"
    android:layout_marginStart="20dp"
    />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="\?"
    android:id="@+id/tv_number_three"
    android:layout_alignParentTop="true"
    android:layout_toRightOf="@+id/tv_number_two"
    android:layout_toEndOf="@+id/tv_number_two"
    android:layout_marginLeft="20dp"
    android:textColor="#67ceff"
    android:textSize="30sp"
    android:layout_marginStart="20dp"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="\?"
    android:id="@+id/tv_number_four"
    android:layout_alignParentTop="true"
    android:layout_toRightOf="@+id/tv_number_three"
    android:layout_toEndOf="@+id/tv_number_three"
    android:textColor="#67ceff"
    android:textSize="30sp"
    android:textIsSelectable="true"
    android:layout_marginLeft="20dp"
    android:layout_marginStart="20dp"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="\?"
    android:id="@+id/tv_number_five"
    android:layout_alignParentTop="true"
    android:layout_toRightOf="@+id/tv_number_four"
    android:layout_toEndOf="@+id/tv_number_four"
    android:layout_marginLeft="20dp"
    android:textColor="#67ceff"
    android:textSize="30sp"
    android:layout_marginStart="20dp"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="\?"
    android:id="@+id/tv_number_six"
    android:layout_alignBottom="@+id/tv_number_five"
    android:layout_toRightOf="@+id/tv_number_five"
    android:layout_toEndOf="@+id/tv_number_five"
    android:textColor="#67ceff"
    android:textSize="30sp"
    android:layout_marginLeft="20dp"
    android:layout_marginStart="20dp"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="\?"
    android:id="@+id/tv_number_seven"
    android:layout_alignParentTop="true"
    android:layout_toRightOf="@+id/tv_number_six"
    android:layout_toEndOf="@+id/tv_number_six"
    android:layout_marginLeft="20dp"
    android:textColor="#6198ff"
    android:textSize="30sp"
    android:layout_marginStart="20dp"/>

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="NEXT NUMBER"
    android:id="@+id/button_next_num"
    android:layout_below="@+id/tv_number_one"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_marginTop="41dp"
    android:onClick="generate"/>

有谁知道怎么做？

Answer 1

只需在onclickListener event of button中添加代码，并在计数达到7时在onclickListener中设置counter integer然后停止。代码如下 -

public class MainActivity extends AppCompatActivity {
int intCount=0;
int[] arr = new int[7];
final Button nextButton;
Random randomGenerator = new Random(); 

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    nextButton = (Button)findviewbyid(R.id.button_next_num)
    TextView tv_number_one = (TextView)findViewById(R.id.tv_number_one);
    TextView tv_number_two = (TextView)findViewById(R.id.tv_number_two);
    TextView tv_number_three = (TextView)findViewById(R.id.tv_number_three);
    TextView tv_number_four = (TextView)findViewById(R.id.tv_number_four);
    TextView tv_number_five = (TextView)findViewById(R.id.tv_number_five);
    TextView tv_number_six = (TextView)findViewById(R.id.tv_number_six);
    TextView tv_number_seven = (TextView)findViewById(R.id.tv_number_seven);

    button.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                // Perform action on click   


             intCount++; //when intCount becomes 7 stop execution
             arr[intCount]= randomGenerator.nextInt(100) + 1;;
               // intCount++; //when intCount becomes 7 stop execution
             if(intCount == 1){tv_number_one.setText(arr[intCount]);}
             else if(intCount == 2){tv_number_two.setText(arr[intCount]);}
             else if(intCount == 3){tv_number_three.setText(arr[intCount]);}
             else if(intCount == 4){tv_number_four.setText(arr[intCount]);}
             else if(intCount == 5){tv_number_five.setText(arr[intCount]);}
             else if(intCount == 6){tv_number_six.setText(arr[intCount]);}
             else if(intCount == 7){tv_number_seven.setText(arr[intCount]);}
             else{ intCount=0;nextButton.setEnabled(false);}
            }
        });    
  }
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
  }

   @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}
}

Answer 2

是的，您的代码将无法运行，因为您创建了一个大小为2的数组，但是您尝试在该数组中获取7个元素，它将引发一个名为ArrayIndexOutOfBound的异常。因为声明的数组有2个元素试图检索更多的元素。为什么不能获得直接随机值并添加到textview。

int clickCount = 0;

public void generate(View v) {
    Random myRandom = new Random();

    if(clickCount >= 7) return;

    TextView tv_number_one = (TextView)findViewById(R.id.tv_number_one);
    TextView tv_number_two = (TextView)findViewById(R.id.tv_number_two);
    TextView tv_number_three = (TextView)findViewById(R.id.tv_number_three);
    TextView tv_number_four = (TextView)findViewById(R.id.tv_number_four);
    TextView tv_number_five = (TextView)findViewById(R.id.tv_number_five);
    TextView tv_number_six = (TextView)findViewById(R.id.tv_number_six);
    TextView tv_number_seven = (TextView)findViewById(R.id.tv_number_seven);

    String randStr = String.valueOf(myRandom.nextInt(48));

    switch(clickCount % 7) {
        case 0:
            tv_number_one.setText(randStr);
            break;

        case 1:
            tv_number_two.setText(randStr);
            break;

        case 2:
            tv_number_three.setText(randStr);
            break;

        case 3:
            tv_number_four.setText(randStr);
            break;

        case 4:
            tv_number_five.setText(randStr);
            break;

        case 5:
            tv_number_six.setText(randStr);
            break;

        case 6:
            tv_number_seven.setText(randStr);
            break;
    }

    clickCount++;
}

还有一件事，String.valueOf()方法将返回String，因此您无需在此之前附加空字符串。

android随机数组

2 个答案: