Java Android-当切换按钮打开时，是否可以迭代生成随机数？

我正在尝试在Android中创建一个应用程序，在切换按钮打开时重复生成数字。因此，当用户再次点击开关将其关闭时，它将停止生成随机数。但我不确定这是否可能，因为由于无限循环，我的代码不断出现运行时错误。 切换按钮打开时是否可以迭代生成随机数

MainActivity.java

package dan.cielos;

import android.widget.CompoundButton;
import android.os.Bundle;
import android.support.design.widget.Snackbar; 
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.MultiAutoCompleteTextView;
import android.app.Activity;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
import android.widget.ToggleButton;
import android.widget.TextView;
import android.widget.NumberPicker;

public class MainActivity extends AppCompatActivity {

//private
private int min = 1;
private int max = 100;
private TextView txt;

/*public boolean recurse(boolean toggle) {
    if (toggle == false) {
        return false;
    }
    else {
        return recurse(toggle);
    }
}*/

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_random);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    NumberPicker np = (NumberPicker) findViewById(R.id.numPick);
    final TextView rn = (TextView) findViewById(R.id.random_number);
    final ToggleButton tog = (ToggleButton) findViewById(R.id.random_button);
    np.setMinValue(min);
    np.setMaxValue(max);
    toolbar.setTitle("Random Number");
    setSupportActionBar(toolbar);

    tog.setOnClickListener(new OnClickListener() {
            public void onClick(View v){
                //recurse(tog.isChecked());
                if (tog.isChecked()) {//the result i want to achieve is while the toggle button is on, iteratively generate numbers until user press the toggle button again

                    double ran = Math.random() * (max -min) + min;
                    ran = Math.round(ran);
                    rn.setText(Double.toString(Math.floor(ran)));

                }

            }
        });
    }


@Override
public boolean onCreateOptionsMenu(Menu menu) {

    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    int id = item.getItemId();

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

    return super.onOptionsItemSelected(item);
}


}

activity_random.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="dan.cielos.MainActivity">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/AppTheme.PopupOverlay" />

 </android.support.design.widget.AppBarLayout>
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Number"
    android:id="@+id/random_number"
    android:textSize="80sp"
    android:layout_above="@+id/random_button"
    android:layout_centerHorizontal="true" />

<ToggleButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="New ToggleButton"
    android:id="@+id/random_button"
    android:height="75dp"
    android:width="150dp"
    android:textOff="Generate"
    android:textOn="Stop"
    android:layout_marginBottom="58dp"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true" />

<NumberPicker
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/numPick"
    android:layout_above="@id/random_number"
    android:layout_centerHorizontal="true" />
</RelativeLayout>
</android.support.design.widget.CoordinatorLayout>

---

无限循环是不好的，因为您不希望程序在生成数字时停止。记住-Android需要运行它的UI，以便正确显示您所做的更改

相反，只要单击“切换”按钮，您就希望每隔很短的时间间隔（比如说每100毫秒？）显示一个不同的随机数

以下是您可以实现此目标的方法：

private boolean isGeneratingRandomNum; // <-- this will prevent duplicate initiations of the "loop"
private boolean isToggleButtonOn; // <-- change this value to true / false depending on whether or not the button is on.

private void displayRandomNumber() {
    // if the toggle button is off, stop
    // if the loop iteration has already started, stop
    if (!isToggleButtonOn || isGeneratingRandomNum)
        return;

    // indicate that the loop iteration has begun
    isGeneratingRandomNum = true;

    // your code for setting a random number
    double ran = Math.random() * (max -min) + min;
    ran = Math.round(ran);
    rn.setText(Double.toString(Math.floor(ran)));

   // set up the next iteration to occur in 100 ms on the ui thread.
   postDelayed(new Runnable() {
       @Override
       public void run() {
           // indicate that the loop iteration is done, meaning we are ready to perform another iteration.
           isGeneratingRandomNum = false;

           // call the method again.
           displayRandomNumber();
       }
   }, 100);
}

// call this method from your toggleButton onClickListener
private void onToggleButtonChange() {
    isToggleButtonOn = !isToggleButtonOn;

    if (isToggleButtonOn)
       displayRandomNumber();
}

---

private boolean isGeneratingRandomNum；//我不知道你的目的和你的代码，但我相信你在UI线程中做无限循环，这就是为什么你会出错。尝试在后台使用AsyncTask或IntentService来执行此操作为什么不？您可以使用标志（启用切换时为true）在函数内部再次调用函数（递归）。遇到问题时，请尝试写信。添加代码段。你正在读取那些随机数吗？也许最好使用一个处理程序，每X毫秒运行一次