本例主要讲述如何用Intent打开第二个页面,再从第二个页面返回第一个页面,现在大多数应用界面都带有返回按钮,貌似显得高级一点,用Intent打开一个activity的用法:首先实例化一个intent对象,Intent intent = new Intent(MainActivity.this, SecondActivity.class);第一个参数为当前Activity,第二个参数为你要打开的Activity,然后调用startActivity(intent);方法,把intent传进去即可,下面上代码:
MainActivity代码:
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
public class MainActivity extends ActionBarActivity {
private ImageView imageView = null;
private Button button = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, SecondActivity.class);
startActivity(intent);
}
});
}
}
MainActivity的布局文件:
<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">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/blue" />
<Button
android:id="@+id/button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="启动下一个Activity" />
</RelativeLayout>
SecondActivity代码:
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.Button;
public class SecondActivity extends ActionBarActivity {
private Button button;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
button = (Button)findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(SecondActivity.this,MainActivity.class);
startActivity(intent);
}
});
}
}
SecondActivity布局文件:
<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="com.example.administrator.intent.SecondActivity">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/yellow" />
<Button
android:id="@+id/button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="返回上一个Activity"/>
</RelativeLayout>
上面两个界面布局用了ImageView添加了两张图片作为背景,用以区分两个Activity,点击"启动下一个Activity"按钮进入SecondActivity,点击"返回上一个Activity"回到MainActivity.效果如下: