三个作业题

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
android:orientation="vertical"
tools:context="com.example.my.myapplication.Test_Suijishu">

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/tv_1"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="生成随机数"
android:onClick="bt1_onClick"
android:id="@+id/bt_1"/>
</LinearLayout>

package com.example.my.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class Test_Suijishu extends AppCompatActivity {

TextView tv_1;
Button bt_1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test__suijishu);
tv_1=(TextView)findViewById(R.id.tv_1);
bt_1=(Button)findViewById(R.id.bt_1);
}
public void bt1_onClick(View v)
{
int[]a=new int[6];
String max="";
String min="";
String result="";
for (int i=0;i<6;i++) {
a[i] = (int) (Math.random() * 10);
while (a[0] == 0) {
a[0] = (int) (Math.random() * 10);
}
result += a[i];
}
tv_1.setText(result);
}

}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
android:orientation="vertical"
tools:context="com.example.my.myapplication.Test_duihuakuang">

<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="提示"
android:onClick="tishi_onClick"/>
</LinearLayout>

package com.example.my.myapplication;

import android.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;

public class Test_duihuakuang extends AppCompatActivity {

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

}
public void tishi_onClick(View v)
{
new AlertDialog.Builder(this)
.setTitle("提示")
.setMessage("确定要删除吗？\n要删除，请点击“是”。")
.setPositiveButton("否", null)
.setNegativeButton("是", null)
.show();
}
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
android:orientation="vertical"
tools:context="com.example.my.myapplication.Test_3">

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="请输入电话号码"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="phone"
android:id="@+id/ed_phone"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="拨出此号码"
android:id="@+id/bt_bd"
android:onClick="bd_onClick"/>
<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="给此号码发短信"
android:id="@+id/bt_fs"
android:onClick="fs_onClick"/>
</LinearLayout>
</LinearLayout>

package com.example.my.myapplication;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class Test_3 extends AppCompatActivity {

EditText ed_phone;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test_3);
ed_phone=(EditText)findViewById(R.id.ed_phone);
}
public void bd_onClick(View v)
{
String phone = getPhone();
if (phone==null)return;
Intent intent=new Intent(Intent.ACTION_DIAL);
Uri uri=Uri.parse("tel:"+phone);
intent.setData(uri);
startActivity(intent);
}
public String getPhone()
{
String phone=ed_phone.getText().toString().trim();
if (phone.length()==0)
{
Toast.makeText(Test_3.this, "请正确填写电话号码", Toast.LENGTH_SHORT).show();
return null;
}
return phone;
}
public String getMessage()
{
String message=ed_phone.getText().toString().trim();
if (message.length()==0)
{
Toast.makeText(Test_3.this, "请正确填写电话号码", Toast.LENGTH_SHORT).show();
return null;
}
return message;
}
public void fs_onClick(View v)
{
String message = getMessage();
if (message == null) return;
Uri smsToUri = Uri.parse("smsto:message");
Intent intent = new Intent(Intent.ACTION_SENDTO, smsToUri);
intent.setData(Uri.parse("smsto:"+message));
startActivity(intent);
}
}