第七周作业

1.三个界面，界面1点击按钮使用显式意图开启界面2.
界面2点击按钮隐式意图开启界面3
2.在界面1做一个按钮开启浏览器访问百度

<?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:gravity="center"
    android:orientation="vertical">

    <Button
        android:id="@+id/bt1"
        android:onClick="onclick"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="显示意图开启界面2"

        />
    <Button
        android:id="@+id/bt2"
        android:onClick="click2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="开启百度"
        android:layout_below="@id/bt1"
        />



</LinearLayout>

<?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=".secondActivity"
    android:gravity="center"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="界面2"
        android:textSize="36dp"
        />
    <Button
        android:id="@+id/bt3"
        android:onClick="click3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="隐式意图开启界面3"
        android:layout_below="@id/bt2"
        />


</LinearLayout>

<?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=".secondActivity"
    android:gravity="center">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="界面3"
        android:textSize="36dp"
        />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.anint">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".thirdActivity">
            <intent-filter>
            <action android:name="cn.itcast.START_ACTIVITY" />

            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
        </activity>
        <activity android:name=".secondActivity">

        </activity>
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

package com.example.anint;
import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button bt1=(Button)findViewById(R.id.bt1);
        Button bt2=(Button)findViewById(R.id.bt2);

        bt1.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent intent=new Intent(MainActivity.this,secondActivity.class);
                startActivity(intent);
            }
        });


    }
    public void click2(View view){
        Intent intent=new Intent();
        intent.setAction("android.intent.action.VIEW");
        intent.setData(Uri.parse("http://www.baidu.com"));
        startActivity(intent);
    }


}

package com.example.anint;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;

public class secondActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);
    }
    public void click3(View v){
        Intent intent = new Intent();
        intent.setAction("cn.itcast.START_ACTIVITY");
        startActivity(intent);
    }


}

   

 

3.2个edittext,4个按钮一个textview，实现简单计算器。

提示1：如何获取edittext上的数据？
String num1=((EditText)(findViewById(R.id.et1))).getText().toString();//获取et1上面的文本，并 
转成字符串
提示2：字符串如何转int
int n1=Integer.parseInt(num1);
提示3:如何把计算结果显示在textview上？
TextView tv1=(TextView)findViewById(R.id.tv1);//获取控件
tv1.setText("1233213");//用settext方法赋值

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"
    tools:context=".MainActivity" >
 
    <EditText
        android:id="@+id/et1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入第一个数"
        android:textSize="50dp"
        android:background="#32FF00"
        android:layout_marginBottom="100dp"
        />
 
    <EditText
        android:id="@+id/et2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入第二个数"
        android:textSize="50dp"
        android:background="#00FFF6"
        android:layout_below="@id/et1"
        android:layout_marginBottom="100dp"
        />
    <Button
        android:layout_below="@id/et2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/b1"
        android:text="+"
        android:textSize="50dp"
        android:textColor="#FF0000"
 
        />
    <Button
        android:layout_below="@id/et2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/b2"
        android:text="-"
        android:textSize="50dp"
        android:layout_toRightOf="@id/b1"
        />
    <Button
        android:layout_below="@id/et2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/b3"
        android:text="*"
        android:textSize="50dp"
        android:layout_toRightOf="@id/b2"
        />
    <Button
        android:layout_below="@id/et2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/b4"
        android:textSize="50dp"
        android:text="/"
        android:layout_toRightOf="@id/b3"
        />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tv"
        android:layout_below="@id/b1"
        android:text="结果是"
        android:textSize="50dp"
        />
 
 
</RelativeLayout>

package com.example.mya;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class ThreeActivity extends AppCompatActivity {

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

        //加法运算
        findViewById(R.id.C1).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.B1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.B2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1+n2;
                TextView jieguo=(TextView)findViewById(R.id.A2);
                jieguo.setText("计算结果是："+n3);
            }
        });

        //减法运算
        findViewById(R.id.C2).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.B1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.B2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1-n2;
                TextView jieguo=(TextView)findViewById(R.id.A2);
                jieguo.setText("计算结果是："+n3);
            }
        });

        //乘法运算
        findViewById(R.id.C3).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.B1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.B2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1*n2;
                TextView jieguo=(TextView)findViewById(R.id.A2);
                jieguo.setText("计算结果是："+n3);
            }
        });

        //除法运算
        findViewById(R.id.C4).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.B1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.B2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1/n2;
                TextView jieguo=(TextView)findViewById(R.id.A2);
                jieguo.setText("计算结果是："+n3);
            }
        });

    }

}

 
package com.example.myapplication;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
 
public class MainActivity extends Activity {
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
//        +
        findViewById(R.id.b1).setOnClickListener(new View.OnClickListener() {
 
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String num1=((EditText)(findViewById(R.id.et1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.et2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1+n2;
                TextView tv1=(TextView)findViewById(R.id.tv);
                tv1.setText("结果是"+n3);
            }
        });
//        -
        findViewById(R.id.b2).setOnClickListener(new View.OnClickListener() {
 
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String num1=((EditText)(findViewById(R.id.et1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.et2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1-n2;
                TextView tv1=(TextView)findViewById(R.id.tv);
                tv1.setText("结果是"+n3);
            }
        });
 
//        *
        findViewById(R.id.b3).setOnClickListener(new View.OnClickListener() {
 
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String num1=((EditText)(findViewById(R.id.et1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.et2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1*n2;
                TextView tv1=(TextView)findViewById(R.id.tv);
                tv1.setText("结果是"+n3);
            }
        });
 
//        /
        findViewById(R.id.b4).setOnClickListener(new View.OnClickListener() {
 
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String num1=((EditText)(findViewById(R.id.et1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.et2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1/n2;
                TextView tv1=(TextView)findViewById(R.id.tv);
                tv1.setText("结果是"+n3);
            }
        });
    }
 
 
}

package com.example.mya;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class ThreeActivity extends AppCompatActivity {

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

        //加法运算
        findViewById(R.id.C1).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.B1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.B2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1+n2;
                TextView jieguo=(TextView)findViewById(R.id.A2);
                jieguo.setText("计算结果是："+n3);
            }
        });

        //减法运算
        findViewById(R.id.C2).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.B1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.B2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1-n2;
                TextView jieguo=(TextView)findViewById(R.id.A2);
                jieguo.setText("计算结果是："+n3);
            }
        });

        //乘法运算
        findViewById(R.id.C3).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.B1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.B2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1*n2;
                TextView jieguo=(TextView)findViewById(R.id.A2);
                jieguo.setText("计算结果是："+n3);
            }
        });

        //除法运算
        findViewById(R.id.C4).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.B1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.B2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1/n2;
                TextView jieguo=(TextView)findViewById(R.id.A2);
                jieguo.setText("计算结果是："+n3);
            }
        });

    }

}

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"
    tools:context=".MainActivity" >
 
    <EditText
        android:id="@+id/et1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入第一个数"
        android:textSize="50dp"
        android:background="#32FF00"
        android:layout_marginBottom="100dp"
        />
 
    <EditText
        android:id="@+id/et2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入第二个数"
        android:textSize="50dp"
        android:background="#00FFF6"
        android:layout_below="@id/et1"
        android:layout_marginBottom="100dp"
        />
    <Button
        android:layout_below="@id/et2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/b1"
        android:text="+"
        android:textSize="50dp"
        android:textColor="#FF0000"
 
        />
    <Button
        android:layout_below="@id/et2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/b2"
        android:text="-"
        android:textSize="50dp"
        android:layout_toRightOf="@id/b1"
        />
    <Button
        android:layout_below="@id/et2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/b3"
        android:text="*"
        android:textSize="50dp"
        android:layout_toRightOf="@id/b2"
        />
    <Button
        android:layout_below="@id/et2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/b4"
        android:textSize="50dp"
        android:text="/"
        android:layout_toRightOf="@id/b3"
        />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tv"
        android:layout_below="@id/b1"
        android:text="结果是"
        android:textSize="50dp"
        />
 
 
</RelativeLayout>package com.example.mya;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class ThreeActivity extends AppCompatActivity {

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

        //加法运算
        findViewById(R.id.C1).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.B1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.B2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1+n2;
                TextView jieguo=(TextView)findViewById(R.id.A2);
                jieguo.setText("计算结果是："+n3);
            }
        });

        //减法运算
        findViewById(R.id.C2).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.B1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.B2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1-n2;
                TextView jieguo=(TextView)findViewById(R.id.A2);
                jieguo.setText("计算结果是："+n3);
            }
        });

        //乘法运算
        findViewById(R.id.C3).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.B1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.B2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1*n2;
                TextView jieguo=(TextView)findViewById(R.id.A2);
                jieguo.setText("计算结果是："+n3);
            }
        });

        //除法运算
        findViewById(R.id.C4).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String num1=((EditText)(findViewById(R.id.B1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.B2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1/n2;
                TextView jieguo=(TextView)findViewById(R.id.A2);
                jieguo.setText("计算结果是："+n3);
            }
        });

    }

} package com.example.myapplication;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
 
public class MainActivity extends Activity {
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
//        +
        findViewById(R.id.b1).setOnClickListener(new View.OnClickListener() {
 
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String num1=((EditText)(findViewById(R.id.et1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.et2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1+n2;
                TextView tv1=(TextView)findViewById(R.id.tv);
                tv1.setText("结果是"+n3);
            }
        });
//        -
        findViewById(R.id.b2).setOnClickListener(new View.OnClickListener() {
 
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String num1=((EditText)(findViewById(R.id.et1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.et2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1-n2;
                TextView tv1=(TextView)findViewById(R.id.tv);
                tv1.setText("结果是"+n3);
            }
        });
 
//        *
        findViewById(R.id.b3).setOnClickListener(new View.OnClickListener() {
 
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String num1=((EditText)(findViewById(R.id.et1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.et2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1*n2;
                TextView tv1=(TextView)findViewById(R.id.tv);
                tv1.setText("结果是"+n3);
            }
        });
 
//        /
        findViewById(R.id.b4).setOnClickListener(new View.OnClickListener() {
 
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String num1=((EditText)(findViewById(R.id.et1))).getText().toString();
                String num2=((EditText)(findViewById(R.id.et2))).getText().toString();
                int n1=Integer.parseInt(num1);
                int n2=Integer.parseInt(num2);
                int n3=n1/n2;
                TextView tv1=(TextView)findViewById(R.id.tv);
                tv1.setText("结果是"+n3);
            }
        });
    }
 
 
}