点击android上的随机7位数字

Question

我希望你能帮我解决这个问题.我可以生成随机数但不是精确计数.

问题是,一旦点击按钮,如何生成7个随机数字？

请参考下面的代码:

    public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final Random myRandom = new Random();


        Button buttonGenerate = (Button)findViewById(R.id.generateme);
        final TextView textGenerateNumber = (TextView)findViewById(R.id.generatenumber);

        buttonGenerate.setOnClickListener(new OnClickListener(){

                 @Override
                 public void onClick(View v) {
                      // TODO Auto-generated method stub
                      textGenerateNumber.setText(String.valueOf(myRandom.nextInt()));
                  }
       });
  }
  }

这是我的XML文件

     <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >

    <Button
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Generate Random number"
    android:id="@+id/generateme"
    />
    <TextView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:id="@+id/generatenumber"
    />
    </LinearLayout

Answer 1

尝试使用此函数中的JAVA的Math和Random类来生成带有"n"数字的随机数.例如7位数的随机数.

private int nDigitRandomNo(int digits){
    int max = (int) Math.pow(10,(digits)) - 1; //for digits =7, max will be 9999999
    int min = (int) Math.pow(10, digits-1); //for digits = 7, min will be 1000000
    int range = max-min; //This is 8999999
    Random r = new Random(); 
    int x = r.nextInt(range);// This will generate random integers in range 0 - 8999999
    int nDigitRandomNo = x+min; //Our random rumber will be any random number x + min
    return nDigitRandomNo;
}
int digits = 7;
int n = nDigitRandomNo(digits);
//n will be a random number between 1000000 - 9999999