Android Studio Development Note one

<span id="Label3"></p><p><p>1.<br>ImageView: A control that displays a picture<br>Property:<br>android:src= "@ path"<br>Android:backgroud= "@ path" serves as background<br>android:backgroud= "#ffffff" color serves as background</p></p><p><p>2.button and ImageButton features:<br>(1) Common features: can be used as a button to generate click events<br>(2) different: button has text property, ImageButton has src attribute<br>(3) Create a noticeable click effect</p></p><p><p>3.onClick Events<br>(1) button and ImageButton all have an onclick event, through their own<br>The. Setonclicklistener (onclicklistener) method to add a click event<br>(2) all controls have an onclick event, not just button and ImageButton have<br>(3) Click on the event of the listener can achieve the Click button after the action of what to Happen.</p></p><p><p> 4. Three ways to listen for event implementations: <br> (1) Implementation of the anonymous inner class <br> (2) implementation of a standalone class <br> (3) implements the interface in a way that implements the <br> Code: <br> activity_main: <br> <?xml version= " 1.0 "encoding=" utf-8 ", <br> <linearlayout xmlns:android=" http://schemas.android.com/apk/res/android "<br> xmlns:tools= "http://schemas.android.com/tools" <br> android:layout_width= "match_parent" <br> Android:layout_height = "match_parent" <br> android:orientation= "vertical" <br> android:paddingbottom= "@dimen/activity_vertical_margin" <br> android:paddingleft= "@dimen/activity_horizontal_margin" <br> android:paddingright= "@dimen/activity_ Horizontal_margin "<br> android:paddingtop=" @dimen/activity_vertical_margin "<br> tools:context=" Com.example.administrator.image.MainActivity "; </p></p><p><p><!--<br>SRC for display picture;<br>Background as background image<br>Orientation represents a layout that can be vertical<br>-<br><!--<br><imageview<br>Android:background= "#cccccc"<br>Android:id= "@+id/imageview1"<br>Android:layout_width= "wrap_content"<br>android:layout_height= "wrap_content"<br>Android:src= "@drawable/img"<br>/><br>-<br><!--<br><imageview<br>Android:id= "@+id/imageview2"<br>Android:layout_width= "match_parent"<br>android:layout_height= "20dp"<br>Android:background= "@drawable/background"<br>/><br>-</p></p><p><p><!--define the name of a button by accessing a string resource<br>android:text= "@string/button_name"<br>-<br><button<br>Android:id= "@+id/button1"<br>Android:layout_width= "wrap_content"<br>android:layout_height= "wrap_content"<br>android:text= "button 1"<br>/><br><button<br>Android:id= "@+id/button2"<br>Android:layout_width= "wrap_content"<br>android:layout_height= "wrap_content"<br>android:text= "button 2"<br>/></p></p><p><p><button<br>Android:id= "@+id/button3"<br>Android:layout_width= "wrap_content"<br>android:layout_height= "wrap_content"<br>Android:src= "@drawable/img"<br>/><br></LinearLayout></p></p><p><p>Mainactivity:<br>Package com.example.administrator.image;</p></p><p><p>Import android.support.v7.app.AppCompatActivity;<br>Import android.os.Bundle;<br>Import android.util.Log;<br>Import android.view.View;<br>Import android.widget.Button;<br>Import android.widget.Toast;</p></p><p><p>public class Mainactivity extends Appcompatactivity {<br>Private Button loginbutton;<br>Private Button loginButton1;<br>Private Button imgbutton;</p></p><p><p>@Override<br>protected void OnCreate (Bundle Savedinstancestate) {<br>Super.oncreate (savedinstancestate);<br>Setcontentview (r.layout.activity_main);<br>/*<br>1. Initialize the currently required control, how to initialize a control?<br>Findviewbyid--returns the object of a view, so it is converted to a button object<br>Findviewbyid how to find the ID of the corresponding view<br>2. Set the listener of the button to implement what we click button to do<br>*/<br>loginbutton= (Button) Findviewbyid (r.id.button1);<br>loginbutton1= (Button) Findviewbyid (r.id.button2);<br>imgbutton= (Button) Findviewbyid (r.id.button3);<br>/*<br>Listener Event Mode: 1. Anonymous inner class</p></p><p><p>Loginbutton.setonclicklistener (new View.onclicklistener () {<br>@Override<br>public void OnClick (View V) {<br>Listen for the action of clicking button in the current OnClick method<br>System.out.println ("my Button was clicked");<br>LOG.I ("tag", "independent Implementation of the onclick event");<br>}<br>});<br>*/</p></p><p><p>/*<br>How to listen to Events: 2. Writing and function of external classes</p></p><p><p>Loginbutton.setonclicklistener (new Myonclicklistener () {<br>@Override<br>public void OnClick (View V) {<br>Calling the onclick of the parent class<br>Super.onclick (v);<br>Toast.maketext (mainactivity.this, "button1 logic to execute", toast.length_long). show ();<br>}<br>});</p></p><p><p>Loginbutton1.setonclicklistener (new Myonclicklistener () {<br>@Override<br>public void OnClick (View V) {<br>Calling the onclick of the parent class<br>Super.onclick (v);<br>Toast.maketext (mainactivity.this, "button2 logic to execute", toast.length_long). show ();<br>}<br>});<br>*/<br>/*<br>Implement listener events by implementing an interface<br>*/<br>}</p></p><p><p>}<br>Onclicklistener is an interface that cannot inherit<br>Class Myonclicklistener implements view.onclicklistener{<br>@Override<br>public void OnClick (View V) {<br>LOG.I ("tag", "onclick Event of the parent class");<br>Let all buttons that use the Click events of the previous external class make an action to change the transparency of the button itself<br>V.setalpha (0.5f);<br>}<br>}</p></p><p><p>Android Studio Development Note one</p></p></span>