Android Activity间传递自定义类的对象
有很多时候都需要在不同的Activity之间传递数据。
实现方法有很多，可以用Bundle来传递，也可以用给Intent用putExtra传递附加参数。
当然也可以传递自定义类的对象。为了让自定义类可以在Activity之间传递，必须符合一些条件。常用的方法是自定义类实现Parcelable接口或Serializable接口。Android中建议实现Parcelable。
下面例子中两种方法都有例子。
传递Parcelable过去，再传递Serializable回来。
WeightParcelable.java
import android.os.Parcel;import android.os.Parcelable;public class WeightParcelable implements Parcelable {private String sex;private double height;//必须的空构造器，因为下面有一个私有的构造器，否则不能new对象public WeightParcelable() {}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public double getHeight() {return height;}public void setHeight(double height) {this.height = height;}@Overridepublic int describeContents() {return 0;}//需要覆盖的方法@Overridepublic void writeToParcel(Parcel out, int flags) {out.writeString(sex);out.writeDouble(height);}//关键的事情public static final Parcelable.Creator<WeightParcelable> CREATOR = new Parcelable.Creator<WeightParcelable>() {public WeightParcelable createFromParcel(Parcel in) {return new WeightParcelable(in);}public WeightParcelable[] newArray(int size) {return new WeightParcelable[size];}};//private WeightParcelable(Parcel in) {sex = in.readString();height = in.readDouble();}}import java.io.Serializable;public class HeightSerializable implements Serializable {private static final long serialVersionUID = 8502706820090766507L;private String sex;private double weight;public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public double getWeight() {return weight;}public void setWeight(double weight) {this.weight = weight;}}import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.util.Log;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.RadioButton;import android.widget.TextView;public class EX03_10 extends Activity {/** Called when the activity is first created. */public static final String parcelableKey = "irdc.ex03_10.parcelableKey";public static final String seralizableKey = "irdc.ex03_10.seralizableKey";private static final String TAG = "EX03_10";@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);Button b1 = (Button) findViewById(R.id.button1);b1.setOnClickListener(new Button.OnClickListener() {public void onClick(View v) {EditText et = (EditText) findViewById(R.id.height);double height = Double.parseDouble(et.getText().toString());String sex = "";RadioButton rb1 = (RadioButton) findViewById(R.id.sex1);if (rb1.isChecked()) {sex = "M";} else {sex = "F";}Intent intent = new Intent();intent.setClass(EX03_10.this, EX03_10_1.class);Bundle bundle = new Bundle();WeightParcelable wp = new WeightParcelable();wp.setSex(sex);wp.setHeight((int) height);bundle.putParcelable(parcelableKey, wp);intent.putExtras(bundle);//注意这里startActivityForResult(intent, 1);}});}//这个是关键@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {Log.d(TAG, "onActivityResult requestCode=" + requestCode+ " resultCode= " + resultCode + " data == null["+ (data == null) + "]");super.onActivityResult(requestCode, resultCode, data);if (requestCode == 1) {if (resultCode == RESULT_OK) {try {HeightSerializable hs = (HeightSerializable) data.getSerializableExtra(seralizableKey);TextView textView4 = (TextView) findViewById(R.id.text4);textView4.setText("性别：" + hs.getSex() + "\n标准体重:"+ hs.getWeight());} catch (Exception e) {e.printStackTrace();}}}}}import java.text.DecimalFormat;import java.text.NumberFormat;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.util.Log;import android.widget.TextView;public class EX03_10_1 extends Activity {private static final String TAG = "EX03_10_1";@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.myalyout);WeightParcelable wp = (WeightParcelable) getIntent().getParcelableExtra(EX03_10.parcelableKey);String sex = wp.getSex();double height = wp.getHeight();String sexText = "";if (sex.equals("M")) {sexText = "男性";} else {sexText = "女性";}String weight = this.getWeight(sex, height);TextView tv1 = (TextView) findViewById(R.id.text1);tv1.setText("性别:" + sexText + "\n身高:" + height + "厘米\n标准体重: " + weight+ "公斤");// 返回对象Intent data = new Intent();HeightSerializable hs = new HeightSerializable();hs.setSex(sexText);hs.setWeight(Double.valueOf(weight));data.putExtra(EX03_10.seralizableKey, hs);//从这里返回对象setResult(RESULT_OK, data);}private String format(double num) {NumberFormat formatter = new DecimalFormat("0.00");String s = formatter.format(num);return s;}private String getWeight(String sex, double height) {String weight = "";if (sex.equals("M")) {weight = format((height - 80) * 0.7);} else {weight = format((height - 70) * 0.6);}return weight;}} 1 楼 windloverain 2010-12-01 不错，学习了，一会试试。 2 楼 whao189 2011-05-19 我有个问题。。想 请教一下。。