自定义View控件

DrawView.java

/*
 * 自定义控件
 * */
package com.frank.control;
import android.content.Context;
import android.graphics.*;
import android.util.AttributeSet;
import android.view.*;

public class DrawView extends View {
	public float currentX = 40;
	public float currentY = 50;
	//定义、创建画笔
	Paint p = new Paint();
	public DrawView(Context context)
	{
		super(context);
	}
	public DrawView(Context context,AttributeSet set)
	{
		super(context,set);
	}
	@Override
	public void onDraw(Canvas canvas)
	{
		super.onDraw(canvas);
		//设置画笔颜色
		p.setColor(Color.RED);
		//绘制一个小圆
		canvas.drawCircle(currentX,currentY,15,p);
	}
	//为该组件的触碰事件重写事件处理方法
	@Override
	public boolean onTouchEvent(MotionEvent event)
	{
		currentX = event.getX();
		currentY = event.getY();
		//通知当前组件重绘自己
		super.invalidate();
		//返回true表明该处理方法已经处理该事件
		return true;
	}
}

activity_main.xml

<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=".MainActivity"
    android:id="@+id/root" >
    
</RelativeLayout>

　　

MainActivity.java

package com.frank.userdfinedcontrol;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.*;
//引用自己定义控件包名
import com.frank.control.*;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        RelativeLayout rl = (RelativeLayout)super.findViewById(R.id.root);
        final DrawView draw = new DrawView(this);
        draw.setMinimumWidth(300);
        draw.setMinimumHeight(500);
        rl.addView(draw);
    }


    @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;
    }
    
}