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>

Activity中代码编写：

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>