在Android中传递数据的方法非常多,本次介绍4中比较常用的数据传递方法:
1.通过Intent传递数据
2.通过静态变量(static)传递数据
3.通过剪贴板(Clipboard)传递数据
4.通过全局对象传递数据
在TransmitDataActivity.java中
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package mobile.android.transmit.data; public class TransmitDataActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super .onCreate(savedInstanceState); setContentView(R.layout.main); Button button1=(Button)findViewById(R.id.button1); Button button2=(Button)findViewById(R.id.button2); Button button3=(Button)findViewById(R.id.button3); Button button4=(Button)findViewById(R.id.button4); button1.setOnClickListener( new ButtonListenner()); button2.setOnClickListener( new ButtonListenner()); button3.setOnClickListener( new ButtonListenner()); button4.setOnClickListener( new ButtonListenner()); } class ButtonListenner implements OnClickListener{ @SuppressLint ( "NewApi" ) @Override public void onClick(View view) { Intent intent= null ; switch (view.getId()) { case R.id.button1: intent= new Intent(TransmitDataActivity. this ,MyActivity1. class ); //保存String类型的值 intent.putExtra( "intent_string" , "通过Intent传递的字符串" ); //保存integer类型的值 intent.putExtra( "intent_integer" , 300 ); Data data= new Data(); data.id= 1000 ; data.name= "Android" ; //保存可序列化的对象 intent.putExtra( "intent_object" , data); //显示用于接收数据的Activity startActivity(intent); break ; case R.id.button2: intent= new Intent(); intent.setClass(TransmitDataActivity. this , MyActivity2. class ); //下面的代码为MyActivity2中放入三个静态变量赋值 MyActivity2.id= 3000 ; MyActivity2.name= "保时捷" ; MyActivity2.data= new Data(); MyActivity2.data.id= 5555 ; MyActivity2.name= "Android" ; startActivity(intent); break ; case R.id.button3: intent= new Intent(TransmitDataActivity. this ,MyActivity3. class ); //获取剪贴板对象(ClipboardManager) ClipboardManager clipboard=(ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE); //创建Data对象 Data clipboardData= new Data(); //设置Data对象中字段的值 clipboardData.id= 6666 ; clipboardData.name= "通过Clipboard传递的数据" ; //创建字节数组输出流对象,用于将Data对象转换为字节流 ByteArrayOutputStream baos= new ByteArrayOutputStream(); //用于保存Data对象生成Base64格式的字符串 String base64Str= "" ; try { ObjectOutputStream oos= new ObjectOutputStream(baos); //将Data对象写入对象输出流 oos.writeObject(clipboardData); //将字节流进行Base64编码 base64Str=Base64.encodeToString(baos.toByteArray(), Base64.DEFAULT); oos.close(); } catch (IOException e) { e.printStackTrace(); } //获取存储文本数据的剪贴板数据对象(ClipData) ClipData clipData=ClipData.newPlainText( "data" , base64Str); //设置主剪贴板 clipboard.setPrimaryClip(clipData); //显示Myactivity3窗口 startActivity(intent); break ; case R.id.button4: //获取MyApp对象 MyApp myApp=(MyApp) getApplicationContext(); myApp.country= "美国" ; myApp.data.id= 1234 ; myApp.data.name= "飞碟" ; intent= new Intent(TransmitDataActivity. this ,MyActivity4. class ); startActivity(intent); break ; default : break ; } } } } |
Data类:这个类是可序列化的,也就是实现了java.io.Serializable接口的类。
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package mobile.android.transmit.data; import java.io.Serializable; public class Data implements Serializable{ public int id; public String name; } |
在Myactivity1.java中:package mobile.android.transmit.data;
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public class MyActivity1 extends Activity{ @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super .onCreate(savedInstanceState); setContentView(R.layout.myactivity); TextView textView=(TextView)findViewById(R.id.textview); //获得String类型的值 String intentString=getIntent().getStringExtra( "intent_string" ); //获得Integer类型的值 int intentInteger=getIntent().getExtras().getInt( "intent_integer" ); //获得Data类型的值 Data data=(Data) getIntent().getExtras().get( "intent_object" ); StringBuffer sb= new StringBuffer(); sb.append( "Intent_string:" ); sb.append(intentString); sb.append( "\n" ); sb.append( "intent_integer:" ); sb.append(intentInteger); sb.append( "\n" ); sb.append( "data.id:" ); sb.append(data.id); sb.append( "\n" ); sb.append( "data.name:" ); sb.append(data.name); sb.append( "\n" ); //在屏幕上输出传递过来的值 textView.setText(sb.toString()); } } |
在Myactivity2.java中:
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package mobile.android.transmit.data; public class MyActivity2 extends Activity{ public static String name; public static int id; public static Data data; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super .onCreate(savedInstanceState); setContentView(R.layout.myactivity); TextView textView=(TextView)findViewById(R.id.textview); StringBuffer sb= new StringBuffer(); sb.append( "name:" ); sb.append(name); sb.append( "\n" ); sb.append( "id:" ); sb.append(id); sb.append( "\n" ); sb.append( "data.id:" ); sb.append(data.id); sb.append( "\n" ); sb.append( "data.name:" ); sb.append(data.name); sb.append( "\n" ); textView.setText(sb.toString()); } } |
在Myactivity3中:
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package mobile.android.transmit.data; public class MyActivity3 extends Activity{ @SuppressLint ( "NewApi" ) @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super .onCreate(savedInstanceState); setContentView(R.layout.myactivity); TextView textView=(TextView)findViewById(R.id.textview); //获取剪贴板对象 ClipboardManager clipboardManager=(ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE); //从剪贴板中获取Base64编码字符串 String base64Str=clipboardManager.getPrimaryClip().getItemAt( 0 ).getText().toString(); //将Base64编码字符串编码成字节数组 byte [] buffer=Base64.decode(base64Str, Base64.DEFAULT); ByteArrayInputStream bais= new ByteArrayInputStream(buffer); try { ObjectInputStream ois= new ObjectInputStream(bais); //将字节流还原成Data对象 Data data=(Data) ois.readObject(); //将Base64编码原文和Data对象字段值显示在TextView控件中 textView.setText(base64Str+ "\n\ndata.id:" +data.id+ "\ndata.name:" +data.name); } catch (Exception e) { e.printStackTrace(); } } } |
在Myactivity4.java中:
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package mobile.android.transmit.data; import android.app.Activity; import android.os.Bundle; import android.widget.TextView; public class MyActivity4 extends Activity{ @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super .onCreate(savedInstanceState); setContentView(R.layout.myactivity); TextView textView=(TextView) findViewById(R.id.textview); MyApp myApp=(MyApp) getApplicationContext(); textView.setText( "MyApp.country:" +myApp.country+ "\nMyApp.data.id:" +myApp.data.id+ "\nMyApp.data.name:" +myApp.data.name); } } |
关于在不同Activity之间传递数据的四种常用方法小编就给大家介绍这么多,希望对大家有所帮助!