Android Getting Started note 1

1. Button Events

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   Show edit box, text Display, button event

   Layout:

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   Layout file:

   <relativelayout xmlns:android= "Http://schemas.android.com/apk/res/android"

   Xmlns:tools= "Http://schemas.android.com/tools"

   Android:layout_width= "Match_parent"

   android:layout_height= "Match_parent"

   android:paddingleft= "@dimen/activity_horizontal_margin"

   android:paddingright= "@dimen/activity_horizontal_margin"

   android:paddingtop= "@dimen/activity_vertical_margin"

   android:paddingbottom= "@dimen/activity_vertical_margin"

   Tools:context= ". MyActivity ">

   <linearlayout

   Android:layout_width= "Fill_parent"

   android:layout_height= "Wrap_content"

   android:orientation= "Vertical" >

   <textview

   Android:layout_width= "Match_parent"

   android:layout_height= "Wrap_content"

   android:text= "@string/clicknum"

   Android:textsize= "32DP"/>

   <edittext

   Android:id= "@+id/numofclick"

   Android:layout_width= "Match_parent"

   android:layout_height= "Wrap_content"

   Android:textsize= "32DP"/>

   <button

   Android:id= "@+id/btn"

   Android:layout_width= "Match_parent"

   android:layout_height= "Wrap_content"

   android:text= "click!"

   Android:textsize= "24DP"

   />

   </LinearLayout>

   </RelativeLayout>

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   Java files:

   @Override

   protected void OnCreate (Bundle savedinstancestate) {

   Super.oncreate (savedinstancestate);

   Setcontentview (r.layout.activity_my);

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   Final EditText et1= (EditText) Findviewbyid (R.id.numofclick);

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   Button btn= (button) Findviewbyid (R.ID.BTN);

   Btn.setonclicklistener (

   New Button.onclicklistener () {

   public void OnClick (View v)

   {

   num=num+1;

   Toast.maketext (Getapplicationcontext (), "Dianji", Toast.length_long). Show ();

   Et1.settext (String.Format ("clicks: \t%d", num));

   }

   }

   );

   }

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   private static int num=0;

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   To get the control's method:

   Findviewbyid ()

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   To establish an event listener:

   Button btn= (button) Findviewbyid (R.ID.BTN);

   Btn.setonclicklistener (

   New Button.onclicklistener () {

   public void OnClick (View v)

   {

   }

   });