編輯:關於Android編程
在Android中傳遞數據的方法非常多,本次介紹4中比較常用的數據傳遞方法:
1.通過Intent傳遞數據
2.通過靜態變量(static)傳遞數據
3.通過剪貼板(Clipboard)傳遞數據
4.通過全局對象傳遞數據
在TransmitDataActivity.java中
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類型的值 intent.putExtra("intent_string", "通過Intent傳遞的字符串"); //保存integer類型的值 intent.putExtra("intent_integer", 300); Data data=new Data(); data.id=1000; data.name="Android"; //保存可序列化的對象 intent.putExtra("intent_object", data); //顯示用於接收數據的Activity startActivity(intent); break; case R.id.button2: intent=new Intent(); intent.setClass(TransmitDataActivity.this, MyActivity2.class); //下面的代碼為MyActivity2中放入三個靜態變量賦值 MyActivity2.id=3000; MyActivity2.name="保時捷"; 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); //獲取剪貼板對象(ClipboardManager) ClipboardManager clipboard=(ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE); //創建Data對象 Data clipboardData=new Data(); //設置Data對象中字段的值 clipboardData.id=6666; clipboardData.name="通過Clipboard傳遞的數據"; //創建字節數組輸出流對象,用於將Data對象轉換為字節流 ByteArrayOutputStream baos=new ByteArrayOutputStream(); //用於保存Data對象生成Base64格式的字符串 String base64Str=""; try { ObjectOutputStream oos=new ObjectOutputStream(baos); //將Data對象寫入對象輸出流 oos.writeObject(clipboardData); //將字節流進行Base64編碼 base64Str=Base64.encodeToString(baos.toByteArray(), Base64.DEFAULT); oos.close(); } catch (IOException e) { e.printStackTrace(); } //獲取存儲文本數據的剪貼板數據對象(ClipData) ClipData clipData=ClipData.newPlainText("data", base64Str); //設置主剪貼板 clipboard.setPrimaryClip(clipData); //顯示Myactivity3窗口 startActivity(intent); break; case R.id.button4: //獲取MyApp對象 MyApp myApp=(MyApp) getApplicationContext(); myApp.country="美國"; myApp.data.id=1234; myApp.data.name="飛碟"; intent=new Intent(TransmitDataActivity.this,MyActivity4.class); startActivity(intent); break; default: break; } } } }
Data類:這個類是可序列化的,也就是實現了java.io.Serializable接口的類。
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;
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); //獲得String類型的值 String intentString=getIntent().getStringExtra("intent_string"); //獲得Integer類型的值 int intentInteger=getIntent().getExtras().getInt("intent_integer"); //獲得Data類型的值 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"); //在屏幕上輸出傳遞過來的值 textView.setText(sb.toString()); } }
在Myactivity2.java中:
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:
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); //獲取剪貼板對象 ClipboardManager clipboardManager=(ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE); //從剪貼板中獲取Base64編碼字符串 String base64Str=clipboardManager.getPrimaryClip().getItemAt(0).getText().toString(); //將Base64編碼字符串編碼成字節數組 byte[] buffer=Base64.decode(base64Str, Base64.DEFAULT); ByteArrayInputStream bais=new ByteArrayInputStream(buffer); try { ObjectInputStream ois=new ObjectInputStream(bais); //將字節流還原成Data對象 Data data=(Data) ois.readObject(); //將Base64編碼原文和Data對象字段值顯示在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:
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); } }
關於在不同Activity之間傳遞數據的四種常用方法小編就給大家介紹這麼多,希望對大家有所幫助!
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