android自定义组件

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="MyView"
>
<attr name="textColor" format="color"/>
<attr name="textSize" format="dimension" />
<attr name="text" format="string"></attr>
</declare-styleable>
</resources>

<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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.myselfcomponent.MainActivity" xmlns:my="http://schemas.android.com/apk/res/com.example.myselfcomponent">

<com.example.myselfcomponent.MyView
android:id="@+id/MyView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
my:textColor="#00ffff"
my:textSize="20sp"
my:text="自定义组件"

/>

</RelativeLayout>
<!-- my:textColor="#00ffff"
的前缀跟命名空间有关系
(tools:context="com.example.myselfcomponent.MainActivity" xmlns:my="http://schemas.android.com/apk/res/com.example.myselfcomponent">)，
可以自定义
-->

package com.example.myselfcomponent;

import android.R.integer;
import android.R.style;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.View;
/**
* 自定义组件
* */
public class MyView extends View{
//画笔
Paint paint;
String text;

public MyView(Context context) {
super(context);
paint=new Paint();
paint.setColor(Color.BLACK);
paint.setTextSize(28);

// TODO Auto-generated constructor stub
}
public MyView(Context context,AttributeSet attrs) {
// TODO Auto-generated constructor stub
super(context, attrs);
paint=new Paint();
TypedArray typedArray=context.obtainStyledAttributes(attrs,R.styleable.MyView);
int color=typedArray.getColor(R.styleable.MyView_textColor, 0xFFFFFF);
float size=typedArray.getDimension(R.styleable.MyView_textSize, 20);
text=typedArray.getString(R.styleable.MyView_text);
paint.setColor(color);
paint.setTextSize(size);
//关闭资源
typedArray.recycle();
}
/**
* 初始化组件时被触发，进行组件的渲染
* Canvas   画布
* */
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
//设置画笔风格为实心
paint.setStyle(Style.FILL);
//绘制正方形
canvas.drawRect(new Rect(10,10,90,90), paint);
paint.setColor(Color.BLUE);
canvas.drawText(text, 10, 110, paint);
}

}

package com.example.myselfcomponent;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}