Android——Activity跳转

Activity_main.xml

<?xmlversion="1.0"encoding="utf-8"?>
<RelativeLayoutxmlns: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="com.hanqi.text3.MainActivity">

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="HelloWorld!"
android:id="@+id/textView"/>

<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="跳转页面"
android:id="@+id/mybutton"
android:layout_below="@+id/textView"
android:layout_toRightOf="@+id/textView"
android:layout_toEndOf="@+id/textView"
android:layout_marginTop="78dp"
android:onClick="onMyButtonClick"
/>
</RelativeLayout>

MainActivity.java

packagecom.hanqi.text3;

importandroid.app.Activity;
importandroid.content.Intent;
importandroid.os.Bundle;
importandroid.util.Log;
importandroid.view.View;

//继承了Activity
publicclassMainActivityextendsActivity{

@Override//覆盖重写了父类的onCreate()
protectedvoidonCreate(BundlesavedInstanceState){
//super父类
//调用了父类的方法
super.onCreate(savedInstanceState);
//设置Java代码和layout文件的关联
//通过R文件的id值
setContentView(R.layout.activity_main);
}
//按钮点击事件的回调函数
publicvoidonMyButtonClick(Viewv)
{
Log.e("ATG","按钮点击事件触发");
//Activity2a2=newActivity2();
//先创建意图Intent
//第一个参数来源实例，就是当前Activity实例
//第二个参数目标类，目标Activity的class
Intentin=newIntent(this,Activity2.class);

//发动意图
startActivity(in);

}
}

需要注意的是这个方法必须符合三个条件：1.public　　2.返回void　　3.只有一个参数View，这个View就是被点击的这个控件。

activity2.xml

<?xmlversion="1.0"encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"
android:layout_height="match_parent"><TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"android:text="大家好"/>
<EditText
android:layout_width="100dp"
android:layout_height="wrap_content"
android:id="@+id/et"
/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="跳转下一个"
android:onClick="onbuttonclick"
/></LinearLayout>

Activity2.java

packagecom.hanqi.text3;importandroid.app.Activity;
importandroid.content.Intent;
importandroid.os.Bundle;
importandroid.os.PersistableBundle;
importandroid.util.Log;
importandroid.view.View;
importandroid.widget.EditText;/**
*CreatedbyAdministratoron2016/3/16.
*/
//回调方法
publicclassActivity2extendsActivity{@Override
protectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);//
setContentView(R.layout.activity2);System.out.println("这是我运行的第一个Activity");//Log.d("text","log输出的信息");
//Log.w("text","log输出的信息");
//Log.e("text","log输出的信息");
//Log.i("text","log输出的信息");
//Log.v("text","log输出的信息");Log.e("TAG","######创建");}
@Override
protectedvoidonStart(){
super.onStart();Log.e("ATG","######启动");}
@Override
protectedvoidonResume(){
super.onResume();
Log.e("ATG","######显示");
}@Override
protectedvoidonPause(){
super.onPause();
Log.e("ATG","######暂停");
}
@Override
protectedvoidonStop(){
super.onStop();
Log.e("ATG","######停止");
}
@Override
protectedvoidonRestart(){
super.onRestart();
Log.e("ATG","######重新启动");
}
//回调方法
//1.在暂停之后和停止之前保存
inti=0;
Stringetkey="edittext";//成员变量
EditTextet;
@Override
protectedvoidonSaveInstanceState(BundleoutState){
//Bundle实际是一个Map，可以存储键值对key/value
i++;
Log.e("ATG","保存="+i);outState.putInt("myKey",i);super.onSaveInstanceState(outState);//保存用户的输入信息
//EditText
//使用id查找并获取View的实例
et=(EditText)findViewById(R.id.et);Stringstr=et.getText().toString();//局部变量Log.e("TAG","获取用户输入="+str);
outState.getString("edittext",str);}//2.恢复销毁前的保持状态
@Override
protectedvoidonRestoreInstanceState(BundlesavedInstanceState){
super.onRestoreInstanceState(savedInstanceState);i=savedInstanceState.getInt("myKey");
Log.e("ATG","获取="+i);//恢复用户数据
Stringstr=savedInstanceState.getString(etkey);
Log.e("ATG","获取str="+str);
//设置输入框里面的内容
//操作View的实例
et=(EditText)findViewById(R.id.et);
et.setText(str);
}@Override
protectedvoidonDestroy(){
super.onDestroy();
Log.e("ATG","######销毁");
}publicvoidonbuttonclick(Viewv)
{
Intentin=newIntent(this,Activity3.class);startActivity(in);
}}

activity3.xml

<?xmlversion="1.0"encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"><Button
android:layout_width="100dp"
android:layout_height="wrap_content"
android:text="关闭"
android:onClick="onClick"
/>
</LinearLayout>

Activity3.java

packagecom.hanqi.text3;importandroid.app.Activity;
importandroid.os.Bundle;
importandroid.os.PersistableBundle;
importandroid.view.View;/**
*CreatedbyAdministratoron2016/3/19.
*/
publicclassActivity3extendsActivity{@Override
publicvoidonCreate(BundlesavedInstanceState,PersistableBundlepersistentState){
super.onCreate(savedInstanceState,persistentState);setContentView(R.layout.activity3);
}
publicvoidonClick(Viewv)
{
//关闭
finish();
}
}

AndroidManifest.xml

<?xmlversion="1.0"encoding="utf-8"?>
<manifestxmlns:android="http://schemas.android.com/apk/res/android"
package="com.hanqi.text3"><application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme"><activityandroid:name=".Activity2">
<intent-filter>
<actionandroid:name="android.intent.action.VIEW"/><categoryandroid:name="android.intent.category.DEFAULT"/>
</intent-filter></activity>
<activityandroid:name=".Activity3">
<intent-filter>
<actionandroid:name="android.intent.action.VIEW"/><categoryandroid:name="android.intent.category.DEFAULT"/>
</intent-filter></activity><activityandroid:name=".MainActivity">
<intent-filter>
<actionandroid:name="android.intent.action.MAIN"/><categoryandroid:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application></manifest>