Android生成随机数的方法实例

package com.example.my_xm_bw_luowei;

import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

import java.util.Random;

public class MainActivity extends AppCompatActivity {

  private Button bt1;
  private EditText et1;
  private EditText et2;
  private TextView tv;
  private int i=0;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    bt1 = (Button) findViewById(R.id.bt1);
    et2 = (EditText) findViewById(R.id.et2);
    tv = (TextView) findViewById(R.id.tv);
    bt1.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        i++;
        String trim2 = et2.getText().toString().trim();
        String s = \"\";
        Random ran =new Random(System.currentTimeMillis());
        Log.d(\"aaa\", \"onClick: \"+i);
        for (int i = 0 ; i <1; i++) {
          s = s + \"\\n\" + ran.nextInt(Integer.parseInt(trim2));
        }
        tv.setText(s+\"\");
        if (i==10){
          tv.setText(\"直接让高金玉上 嘻嘻嘻\");
        }
      }
    });
  }

}

<?xml version=\"1.0\" encoding=\"utf-8\"?>
<LinearLayout 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\"
  tools:context=\".MainActivity\"
  android:orientation=\"vertical\"
  >

  <Button
    android:text=\"高金玉\"
    android:id=\"@+id/bt1\"
    android:background=\"#ffffff\"
    android:layout_width=\"wrap_content\"
    android:layout_height=\"wrap_content\"></Button>
  <EditText
    android:id=\"@+id/et2\"
    android:hint=\"0-n\"
    android:layout_width=\"match_parent\"
    android:layout_height=\"wrap_content\"></EditText>
  <TextView
    android:textColor=\"#DD0D0D\"
    android:textSize=\"50dp\"
    android:id=\"@+id/tv\"
    android:text=\"0\"
    android:layout_width=\"wrap_content\"
    android:layout_height=\"wrap_content\"></TextView>
</LinearLayout>