android学习之旅——01——Activity与Intent

Intent的基本作用

一个Intent对象包含了一组信息

1，Component name

2，Action

3，Data

4，Category

5，Extras

6，Flags

第一个 Activity: Android02Activity

package com.org;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class Android02Activity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //布局
        setContentView(R.layout.main);
        //取得Button对象
        Button btn = (Button)findViewById(R.id.mybtn);
        btn.setText("点击");
        //btn注册事件
        btn.setOnClickListener(new MyBtnListener());
    }
    class MyBtnListener implements OnClickListener{
    	@Override
    	public void onClick(View v) {
    		// TODO Auto-generated method stub
    		//生成一个intent对象
    		Intent intent = new Intent();
    		//intent传递数据
    		intent.putExtra("name", "jingjing"); 
    		intent.setClass(Android02Activity.this, OtherActivity.class);
    		//启动intent
    		Android02Activity.this.startActivity(intent);
    		
    		//发送短信
    		/*Uri uri = Uri.parse("smsto://0800000123");
    		Intent intent = new Intent(Intent.ACTION_SENDTO,uri);
    		intent.putExtra("name", "lisi");
    		startActivity(intent);*/
    	}
    }
}

第二个Activity: OtherActivity

package com.org;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

public class OtherActivity extends Activity {
	private TextView text ;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		// 如果是R.layout.main 提示错误
		setContentView(R.layout.other);
		
		Intent intent = getIntent();
		String name = intent.getStringExtra("name");
		
		text = (TextView)findViewById(R.id.mytext);
		text.setText(name);
	}
}

Android02Activity的布局文件 main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<Button
    android:id="@+id/mybtn"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    />
</LinearLayout>

OtherActivity的布局文件 other.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView
    android:id="@+id/mytext"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    />
</LinearLayout>

最后要在AndroidManifest.xml文件中注册 Activity

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.org"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="4" />

    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".Android02Activity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
            
        </activity>
        
        <!-- 注册Activity -->
        <activity android:name=".OtherActivity"
                  android:label="@string/other">
     
        </activity>

    </application>
</manifest>

不然会报异常