How to implement data transfer between activities and Android _android

This article illustrates the method of data transfer between Android implementation activities. Share to everyone for your reference. The specific analysis is as follows:

First, explain the start and shutdown of activity:

1. StartActivity (Intent Intent); Start activity
Finish (); End Current Activity
2. Startactivityforresult (Intent Intent, int requestcode); Starts an activity with the specified request code Requestcode
finishacitivity (int requestcode); Ends an activity initiated with the Startactivityforresult (Intent Intent, int requestcode) method
If there are multiple activity, then we have to close one of them, then we can set the Requestcode to close the corresponding activity.

Next, we'll talk about data transfer. The problem is this: if we have some data from page A to page b,a, such as user information (username, account number, password, etc.), from a to page B, in B we want to get the data information, how to pass it?

Intent provides a variety of ways to carry additional data information:

Putextras (Bundle data): Put a drug-carrying packet into the intent
Bundle Getextras (): Remove the packets carried in the intent and get a Bundle object
Putextra (String name, Xxx value): Storing the data in the form of a key value in intent to the Key-value
GetXXX (String name): Gets the corresponding data information from the intent according to the key
Putxxx (String key, XXX data): Put the XXX type of data information into the bundle
GetXXX (String key): Get key data information from bundle
Putserializable (String key, Serializable data): Place an object that can be serialized into the bundle
Getserializable (String key, Serializable data): Remove an object that can be serialized from the bundle

With these methods, we are able to deliver data:
The method is as follows:

1. In page A click on the button bn, jump to the page B code as follows:

int requestcode = 0;
Bn.setonclicklistener (New Onclicklistener ())
{
 @Override public
  void OnClick (View source)
 {
  Intent intent= New (A.this, b.class);
  Startactivityforresult (Intent, inquestcode);
  Opens the specified activity B and waits for the returned result,
  //Where Inquestcode is the request code
  }
}

2. Add the data in page B, the code is as follows:

Intent Intent = Getintent ();
Gets the intent
Intent.putextra ("Data content", "I am Li Ming") corresponding to the currently initiated acitivity B;
Bind data information to intent "I am Li Ming"
b.this.setresult (1, intent);
Set the result code and set the activity B.this.finish () returned after the end
;

3. To obtain the data information in a, the code is as follows:

In page A, in order to get the result returned in B, we should rewrite the Onactivityresult () method in Page A, which will be invoked when B returns the result:

String MyData;
@override public
void Onacitivityresult (int requestcode,int resultcode,intent Intent)
// Override this method to obtain the result returned by B
{
  if (requestcode==0&&resultcode==1)
  {
    Bundle data = Intent.getextras ();
    String myresultdata = data.getstring ("Data Content");
    So myresultdata is the data message we're going to pass from B}

Summing up, by using the methods in intent we can achieve data transfer between different activity, by setting the identifier and result code, we can selectively open and close different activity, which is the data transfer between the activity.

I hope this article will help you with your Android program.