Android——Intent,Bundle

• Intent——切换activity
  

  intent.setClass(first.this,second.class);
  startActivity(intent);

• Bundle——切换时数据传递
  

  //跳转
  Intent intent = new Intent();
  //跳转时数据传输
  Bundle bundle = new Bundle();
  intent.setClass(MainActivity.this, SecondActivity.class);
  bundle.putString("message", str);
  intent.putExtras(bundle);
  startActivity(intent);

  Bundle bundle = this.getIntent().getExtras();
  String message = bundle.getString("message");

Source Code:

package com.example.intent;

import android.os.Bundle;
import android.R.string;
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;
import android.widget.EditText;

public class MainActivity extends Activity {
    
    private EditText myText;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        Button button = (Button)findViewById(R.id.button1);
        myText = (EditText)findViewById(R.id.editText1);
        
        button.setOnClickListener(new OnClickListener() {
            @Override 
            public void onClick(View v) {
                
                String str = myText.getText().toString();
                //跳转
                Intent intent = new Intent();
                //跳转时数据传输
                Bundle bundle = new Bundle();
                
                intent.setClass(MainActivity.this, SecondActivity.class);
                bundle.putString("message", str);
                intent.putExtras(bundle);
                
                
                startActivity(intent);
                
            }
        });
        
        
    }

    
}

package com.example.intent;

import android.app.Activity;
import android.os.Bundle;
import android.view.TextureView;
import android.widget.TextView;

public class SecondActivity extends Activity{
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.second);
        
        Bundle bundle = this.getIntent().getExtras();
        String message = bundle.getString("message");
        
        TextView myText = (TextView)findViewById(R.id.textView2);
        myText.setText(message);
        
    }
    
}

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">Intent</string>
    <string name="action_settings">Settings</string>
    <string name="hello_world">Hello world!</string>
    <string name="Tree">TreeDream</string>

</resources>

<?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:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/Tree" />
    
    <TextView
           android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="TextView" />

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/x" />



</LinearLayout>

<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" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView1"
        android:layout_below="@+id/textView1"
        android:layout_marginTop="51dp"
        android:text="Turn to the secondActivity." />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/textView1"
        android:ems="10" >

        <requestFocus />
    </EditText>

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_toRightOf="@+id/textView1"
        android:src="@drawable/y" />

</RelativeLayout>