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
要求,按钮点击功能使用setOnclickListener方式
2.在界面1做一个按钮开启浏览器访问百度
package com.example.app6;
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,Activity2.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.app6;
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 Activity2 extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_activity2);
Button bt2=(Button)findViewById(R.id.bt2);
bt2.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent=new Intent();
intent.setAction("com.lrp.start");
intent.addCategory("android.intent.category.DEFAULT");
startActivity(intent);
}
});
}
}
package com.example.app6;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
public class Activity3 extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_activity3);
}
}
<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/bt1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="开启界面二"
/>
<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"
/>
</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=".Activity2" >
<Button
android:id="@+id/bt2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="开启界面三"
/>
</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=".Activity3" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/hello_world" />
</RelativeLayout>
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.app6"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.app6.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.app6.Activity2"
android:label="@string/title_activity_activity2" >
</activity>
<activity
android:name="com.example.app6.Activity3"
android:label="@string/title_activity_activity3" >
<intent-filter>
<action android:name="com.lrp.start" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
</application>
</manifest>
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
package com.example.app7;
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);
}
});
}
}
<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" >
<EditText
android:id="@+id/et1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="请输入第一个数"
/>
<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:layout_below="@id/et1"
/>
<Button
android:layout_below="@id/et2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/b1"
android:text="+"
/>
<Button
android:layout_below="@id/et2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/b2"
android:text="-"
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: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: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"
/>
</RelativeLayout>
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