在Android应用中,如何在活动之间传递数据?
Intent i = new Intent(getApplicationContext(), ActivityB.class);
i.putExtra(key, value);
startActivity(i);
然后在另一个活动中检索这些值。
Bundle extras = getIntent().getExtras();
if(extras !=null) {
String value = extras.getString(key);
}
public class GlobalClass extends Application
{
private float vitamin_a;
public float getVitaminA() {
return vitamin_a;
}
public void setVitaminA(float vitamin_a) {
this.vitamin_a = vitamin_a;
}
}
您可以从所有其他类中调用此类的设置器和获取器。要做到这一点,您需要在每个Activity中创建一个GlobalClass对象:
GlobalClass gc = (GlobalClass) getApplication();
gc.getVitaminA()
SharedPreferences preferences =getApplicationContext().getSharedPreferences("name", MainActivity.MODE_PRIVATE);
android.content.SharedPreferences.Editor editor = preferences.edit();
editor.putString("name", "Wally");
editor.commit();
SharedPreferences preferences = getApplicationContext().getSharedPreferences("name", MainActivity.MODE_PRIVATE);
if(preferences.contains("name")){
Toast.makeText(getApplicationContext(), preferences.getString("name", "null"), Toast.LENGTH_LONG).show();
}