Android 点击生成随机数。

来源：互联网发布：linux history 条数编辑：程序博客网时间：2024/06/03 06:43

原文：生产随机数
代码：

public class MainActivity extends Activity {    private Button button;    private String code;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        button=(Button)findViewById(R.id.aa);        button.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {            //true 和false代表是否随机数字，4代表几位随机数。                code = createRandom(true,4);                Toast.makeText(getApplicationContext(),""+code,Toast.LENGTH_SHORT).show();            }        });    }    public static String createRandom(boolean numberFlag, int length){        String retStr = "";        String strTable = numberFlag ? "1234567890" : "1234567890abcdefghijkmnpqrstuvwxyz";        int len = strTable.length();        boolean bDone = true;        do {            retStr = "";            int count = 0;            for (int i = 0; i < length; i++) {                double dblR = Math.random() * len;                int intR = (int) Math.floor(dblR);                char c = strTable.charAt(intR);                if (('0' <= c) && (c <= '9')) {                    count++;                }                retStr += strTable.charAt(intR);            }            if (count >= 2) {                bDone = false;            }        } while (bDone);        return retStr;    }}

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