The basics of the Android custom control family

I. Overview

In Android development, many UI controls often need to be customized to meet the needs of the application or to achieve more results, followed by a series to introduce the custom control, here is more through a number of cases to learn, this series has some typical applications, Well, you can also go to the innovation to develop some better UI, this time with a simple case to master some basic knowledge-how to define properties in the custom control.

Second, the realization of a simple radiobutton

　1. Write type Mradiobutton extension radiobutton

public class Mradiobutton extends RadioButton {...    }

　2. In the Mradiobutton class, custom attributes

We can define our own properties in the control, we can define multiple properties, but we must encapsulate the Set/get method, which is written by specification. such as the Mvalue property, like the following code

Private String Mvalue;    Public String Getmvalue () {        return mvalue;    }    public void Setmvalue (String mvalue) {        this.mvalue = mvalue;    }

　　3. Write Attrs.xml resources for custom attributes

The resource file is placed in the Res/values directory with the following contents:

<?xml version= "1.0" encoding= "Utf-8"?><resources> <declare-styleable    name= "Mradiobutton" >            <!– Property Name--        <attr name= "value" format= "string"/>    </declare-styleable></ Resources>

　4. Define constructors in the Mradiobutton class, initialize properties

            Public Mradiobutton (Context context) {        super (context);    } Public Mradiobutton (context context, AttributeSet attrs, int defstyle) {        Super (context, attrs, Defstyle);    }        Public Mradiobutton (context context, AttributeSet Attrs) {        Super (context, attrs);        Load a name from the Attrs.xml. Mradiobutton ' declare-styleable resources    TypedArray Tarray = context.obtainstyledattributes (Attrs, R.styleable.mradiobutton);        Associates the property value with the attribute in the class mvalue    this.mvalue = tarray.getstring (r.styleable.mradiobutton_value);        Recycle Tarray Object    tarray.recycle ();    }

5. Add the Mradiobutton component to the layout file in Mainactivity, as shown below

<relativelayout xmlns:android= "http://schemas.android.com/apk/res/android"    xmlns:tools= "http// Schemas.android.com/tools "    xmlns:jereh=" Http://schemas.android.com/apk/res/com.jereh. View "    android: Layout_width= "Match_parent"    android:layout_height= "match_parent"    tools:context= " Com.example.zdyview.MainActivity ">    <com.itc.zidingyiview.mradiobutton        android:layout_width=" Match_parent "        android:layout_height=" match_parent "        android:id=" @+id/mrb "        jereh:value=" Hello "        /></relativelayout>

6, Mainactivity Code:

public class Mainactivity extends Activity {    private Mradiobutton RB;    @Override    protected void onCreate (Bundle savedinstancestate) {        super.oncreate (savedinstancestate);        Setcontentview (r.layout.activity_main);        rb= (Mradiobutton) Super.findviewbyid (R.ID.MRB);        Rb.setonclicklistener (New View.onclicklistener () {            @Override public            void OnClick (View v) {Toast.maketext ( Mainactivity.this, Rb.getmvalue (), Toast.length_long). Show ();}}        );}    }

The basics of the Android custom control family