使用Intent启动activity:
Intent intent = new Intent(MainActivity.this, OtherActivity.class); startActivity(intent);
使用Intent启动其他app的activity:
Intent intent = new Intent(); intent.setClassName("com.example.project1","com.example.project1.MainActivity"); startActivity(intent);
com.example.project1是AndroidManifest.xml文件中的package值,
com.example.project1.MainActivity是目标Activity的完整类名。
Intent传值:
intent.putExtra("key", value);
Intent传类实例:
User user=new User("cc","lulu");
intent.putExtra("obj",user);
//getIntent().getSerializableExtra("obj");
或者:
User user=new User("cc","lulu"); Bundle bundle=new Bundle(); bundle.putSerializable("obj", user); intent.putExtra("obj", bundle);
User类必须实现Serializable接口。
Parcelable方式:
public class User2 implements Parcelable { private String name; private String password; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public User2() { } public User2(String name, String password) { super(); this.name = name; this.password = password; } @Override public String toString() { return "User [name=" + name + ", password=" + password + "]"; } @Override public int describeContents() { return 0; } /** * 调用Parcel#writeXXX()方法把User2字段一一写出。类型要对应。 */ @Override public void writeToParcel(Parcel dest, int flags) { dest.writeString(name); dest.writeString(password); } /** * 必须提供一个名为CREATOR的常量。 */ public static final Parcelable.Creator<User2> CREATOR = new Parcelable.Creator<User2>() { /** * 调用Parcel#readXxx()方法,读取顺序必须与写出顺序相同。 */ @Override public User2 createFromParcel(Parcel source) { User2 user2 = new User2(); user2.name = source.readString(); user2.password = source.readString(); return user2; } /** * new出一个数组 */ @Override public User2[] newArray(int size) { return new User2[size]; } }; }
存数据:
Intent intent=new Intent(MainActivity.this,OtherActivity.class); User2 user2=new User2("cc","lubang"); intent.putExtra("obj", user2); startActivity(intent);
取数据:
User2 user = intent.getParcelableExtra("obj"); Log.i("OtherActivity", user.toString());
Parcelable传递数据效率更高。