android组件之Activity
用两种方法实现两个界面的切换，
第一种，更换布局文件：
在main布局文件中：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="第一页" />
<Button
android:id="@+id/layout1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="下一页" />
</LinearLayout>
在second布局文件中：
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="vertical" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="第二页" /> <Button android:id="@+id/layout2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="上一页" /> </LinearLayout>
package cn.sword.activity;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class FirstActivity extends Activity {
Button btn1;
Button btn2;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
findViews();
btn1.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
nextLayout();
}
});
}
public void upLayout(){
setContentView(R.layout.main);
btn1 = (Button) this.findViewById(R.id.layout1);
btn1.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
nextLayout();
}
});
}
public void nextLayout() {
setContentView(R.layout.second);
btn2 = (Button) this.findViewById(R.id.layout2);
btn2.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
upLayout();
}
});
}
public void findViews(){
btn2 = //获取可编辑文本框的ID
btn1 = (Button) this.findViewById(R.id.layout1);//获取Button按钮的ID
}
}
第二种方法，两个Activity进行替换，同样有两个布局文件，分别对应两个Activity：
布局main中：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/first"
android:layout_gravity="center"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/first_btn"
android:text="下一页"
android:layout_gravity="center"/>
</LinearLayout>
在main布局对应的FirstActivity中的代码编写：
package cn.sword.activity;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class FirstActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button btn1 = (Button) this.findViewById(R.id.first_btn);
btn1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(FirstActivity.this,SecondActivity.class);
FirstActivity.this.startActivity(intent);
}
});
}
}
secondlayout布局文件中：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/second"
android:layout_gravity="center" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/second_btn"
android:text="上一页"
android:layout_gravity="center"/>
</LinearLayout>
在secondlayout布局文件对应的SecondActivity中的代码编写：
package cn.sword.activity; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class SecondActivity extends Activity { protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); this.setContentView(R.layout.secondlayout); Button btn2 = (Button) this.findViewById(R.id.second_btn); btn2.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent(SecondActivity.this,FirstActivity.class); SecondActivity.this.startActivity(intent); } }); } }
上面两步完成之后，要记得在AndroidManifest.xml文件配置SecondActivity：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="cn.sword.activity"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="8" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:label="@string/app_name"
android:name=".FirstActivity" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:label="@string/app_name"
android:name=".SecondActivity"></activity>
</application>
</manifest>