android练习

package com.example.wang.testapp2;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import java.util.Random;

public class ZuoyeActivity extends AppCompatActivity {

    Button bt_2;
    Button bt_3;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_zuoye);

        bt_2=(Button)findViewById(R.id.bt_2);
        bt_3=(Button)findViewById(R.id.bt_3);
    }

    //
    public void bt1_OnClick(View v)
    {
        String string="";



        Random random = new Random();

        final String[] str =new String[6];

        for(int i=0;i<6;i++)
        {
            int t=random.nextInt(9);

            str[i]=String.valueOf(t);

            string=string+str[i];

        }
        if (str[0]=="0")
        {
            str[0]=String.valueOf(random.nextInt(9));

            string=str[0]+str[1]+str[2]+str[3]+str[4]+str[5];
        }

        Log.e("TAG", "string=" + string);

        View view=View.inflate(this,R.layout.activity_zuoye2,null);

      final AlertDialog alertDialog = new AlertDialog.Builder(this)

                .setTitle("生成最大值和最小值")
                .setView(view)
                .setPositiveButton("最小值", new DialogInterface.OnClickListener() {

                    String string1="";
                    @Override
                    public void onClick(DialogInterface dialog, int which) {

                        AlertDialog al =(AlertDialog)dialog;

                        int[] a = new int[6];
                        for (int i = 0; i < 6; i++) {
                            a[i] = Integer.parseInt(str[i]);
                            Log.e("TAG","a[}="+a[i]);
                        }

                        for (int i = 0; i < 6; i++) {
                            for (int j = 0; j < 5-i; j++) {
                                if (a[j] > a[j + 1]) {
                                    int b = a[j];

                                    a[j] = a[j + 1];
                                    a[j + 1] = b;
                                }
                            }
                        }
                        for (int i = 0; i < 6; i++) {

                            str[i]=String.valueOf(a[i]);

                            string1=string1+str[i];
                        }

                        Intent intent=new Intent(ZuoyeActivity.this,ZuoyeActivity3.class);

                        //intent.setData(Uri.parse(string1));

                        intent.putExtra("jieguo",string1);

                        startActivity(intent);

//                       EditText et_jieguo=(EditText)al.findViewById(R.id.et_jieguo);
//
//                        et_jieguo.setText(string1);


                    }

                })
                .setNegativeButton("最大值", null)
                .show();

        EditText et_suiji=(EditText)alertDialog.findViewById(R.id.et_suiji);

        et_suiji.setText(string);


    }

    public void bt2_OnClick(View v)
    {
        final AlertDialog alertDialog=new AlertDialog.Builder(this)

                .setTitle("提示")
                .setMessage("确定要删除吗？" + "\n" + "要删除，请点击“是”。")
                .setNegativeButton("否", null)
                .setPositiveButton("是", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        Toast.makeText(ZuoyeActivity.this, "删除成功" + which, Toast.LENGTH_SHORT).show();

                    }
                })
                .show();
    }

    public void bt3_OnClick(View v)
    {

         View  view=View.inflate(this, R.layout.activity_zuoye1, null);
        
        new AlertDialog.Builder(this)
                .setTitle("请输入电话号码")
                .setView(view)
                .setNeutralButton("拨出此号码", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {

                        AlertDialog al = (AlertDialog) dialog;

                        EditText et_1 = (EditText) al.findViewById(R.id.et_1);

                        String str = et_1.getText().toString();

                        Intent intent = new Intent(Intent.ACTION_CALL);

                        intent.setData(Uri.parse("tel:" + str));

                        try {
                            startActivity(intent);

                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                })
                .setPositiveButton("向此号码发短信", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {

                        AlertDialog al=(AlertDialog)dialog;

                        EditText et_1 = (EditText) al.findViewById(R.id.et_1);

                        String str = et_1.getText().toString();

                        Intent intent = new Intent(Intent.ACTION_SENDTO);

                        intent.setData(Uri.parse("smsto:"+str));

                        startActivity(intent);

                    }
                })
                .show();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.wang.testapp2.ZuoyeActivity3">



    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:id="@+id/et_jieguo" />

</RelativeLayout>

package com.example.wang.testapp2;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.EditText;

public class ZuoyeActivity3 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_zuoye3);

        EditText et_jieguo=(EditText)findViewById(R.id.et_jieguo);

        Intent intent=getIntent();

        String s=intent.getStringExtra("jieguo");

        et_jieguo.setText(s);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="练习题1"
        android:id="@+id/bt_1"
        android:onClick="bt1_OnClick"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="练习题2"
        android:id="@+id/bt_2"
        android:onClick="bt2_OnClick"/>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="练习题3"
        android:id="@+id/bt_3"
        android:onClick="bt3_OnClick"/>

</LinearLayout>

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

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="随机数："
            android:textSize="25sp"/>
        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/et_suiji" />

    </LinearLayout>

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:id="@+id/et_jieguo" />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.wang.testapp2.ZuoyeActivity3">



    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:id="@+id/et_jieguo" />

</RelativeLayout>