Android Learning Note (11)-Returning results from intent

Returning results from intent

The StartActivity () method call has an activity but does not return the result to the current activity. When you want to return data from an activity, use the Startactivityforresult () method.

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1. Use the project created in the previous article to add the text box and button to the Secondactivity.xml file, such as the following code:

    <textview        android:layout_width= "fill_parent"        android:layout_height= "wrap_content"        android:text= "Please enter your name"/>    <edittext        android:id= "@+id/txt_username" android:layout_width= "Fill_        Parent "        android:layout_height=" wrap_content "/>    <button        android:id=" @+id/btn_ok "        Android : layout_width= "fill_parent"        android:layout_height= "wrap_content"        android:onclick= "OnClick        " android:text= "OK"/>

2. Add the OnClick () method to the Secondactivity.java file, such as the following code:

public void OnClick (View v) {Intent data = new Intent (); EditText txt_username = (EditText) Findviewbyid (r.id.txt_username);//Use the SetData () method to return data using a intent object Data.setdata ( Uri.parse (Txt_username.gettext (). toString ()));//Setresult () method sets the result code and the data to be passed back to the calling activity Setresult (RESULT_OK, data);// Close Activityfinish ();}

3. Add in the Mainactivity.java file? For example, the following code:

In the OnClick () method:

Startactivityforresult (New Intent (this, secondactivity.class), request_code);// This method invokes an activity and waits for the result to be returned from this activity: Incoming intent object and request code (only an integer value that identifies the activity being called)

Custom Onactivityresult () method:

When an activity returns, you must call your own implementation of the Onactivityresult () method public void Onactivityresult (int requestcode, int resultcode, Intent data) {if (Requestcode = = Request_code) {//Test request code if (ResultCode = = RESULT_OK) {//test result code Toast.maketext (this, Data.getdata (). toString (), Toast.length_short). Show ();}}}

4, implementation, effects such as the following:

Click button:

Enter a name and click OK:

Summarize:

1, call Onstartactivityforresult () method and set the request code;

2, in the called activity, through the intent object callback data and set the result code (SetData () method and Setresult () method);

3, in the invocation activity, the custom Onactivityresult () method, first verifies the request code and the result code, then carries on the other processing.