第四次作业
1.
package com.example.tn1; import android.os.Bundle; import android.app.Activity; import android.content.Intent; import android.view.Menu; import android.view.View; public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } public void click1(View view){ Intent intent =new Intent(this,SecendActivity.class); startActivity(intent); } }
<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=".MainActivity" > <Button android:id="@+id/btu1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="界面1按钮" android:onClick="click1" /> </RelativeLayout>
<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=".SecendActivity" > <Button android:id="@+id/btu2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="界面2按钮" android:onClick="click2" /> </RelativeLayout>
<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=".ThirdActivity" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="界面3" /> </RelativeLayout>
2.
package com.example.charp2; import android.net.Uri; import android.os.Bundle; import android.app.Activity; import android.content.Intent; import android.view.Menu; import android.view.View; public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } public void click1(View view){ Intent intent=new Intent(); intent.setAction("android.intent.action.VIEW"); intent.setData(Uri.parse("http://www.baidu.com")); startActivity(intent); } }
<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=".MainActivity" > <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="打开浏览器" android:onClick="click1" /> </RelativeLayout>
3.
<?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:orientation="vertical"> <EditText android:id="@+id/edt1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="输入第一个数" android:textSize="25dp" /> <EditText android:id="@+id/edt2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="输入第二个数" android:textSize="25dp" /> <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" > <Button android:id="@+id/btn_1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="+" android:textSize="25dp" android:onClick="click1" /> <Button android:id="@+id/btn2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="-" android:textSize="25dp" android:onClick="click2" /> <Button android:id="@+id/btn3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="*" android:textSize="25dp" android:onClick="click3" /> <Button android:id="@+id/btn4" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="/" android:textSize="25dp" android:onClick="click4"/> </LinearLayout> <TextView android:id="@+id/tv1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="结果是" android:textSize="25dp" /> </LinearLayout>
package com.example.myapplication; import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.EditText; import android.widget.TextView; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); findViewById(R.id.btn_1).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String num1=((EditText)(findViewById(R.id.edt1))).getText().toString(); int n1=Integer.parseInt(num1); String num2=((EditText)(findViewById(R.id.edt2))).getText().toString(); int n2=Integer.parseInt(num2); TextView tv1=(TextView) findViewById(R.id.tv1); int n3=n1+n2; tv1.setText("答案是"+n3); } }); findViewById(R.id.btn2).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String num1=((EditText)(findViewById(R.id.edt1))).getText().toString(); int n1=Integer.parseInt(num1); String num2=((EditText)(findViewById(R.id.edt2))).getText().toString(); int n2=Integer.parseInt(num2); TextView tv1=(TextView) findViewById(R.id.tv1); int n3=n1-n2; tv1.setText(n3); } }); findViewById(R.id.btn3).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String num1=((EditText)(findViewById(R.id.edt1))).getText().toString(); int n1=Integer.parseInt(num1); String num2=((EditText)(findViewById(R.id.edt2))).getText().toString(); int n2=Integer.parseInt(num2); TextView tv1=(TextView) findViewById(R.id.tv1); int n3=n1*n2; tv1.setText(n3); } });findViewById(R.id.btn4).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String num1=((EditText)(findViewById(R.id.edt1))).getText().toString(); int n1=Integer.parseInt(num1); String num2=((EditText)(findViewById(R.id.edt2))).getText().toString(); int n2=Integer.parseInt(num2); TextView tv1=(TextView) findViewById(R.id.tv1); int n3=n1/n2; tv1.setText(n3); } }); } }