Android学习之自定义控件

常用的自定义控件的方式大致有三种：

        1.继承自现有控件，加以改进，如继承TextView；

        2.将几种控件进行组合，构成新的组件；

        3.继承View类，重绘一个组件。

自定义控件的方法：

首先定义一个自定义控件类(MyView.java)：

</pre><pre name="code" class="html">package com.jtext.chessdisplay;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Toast;

public class MyView extends View{

	Context context1;
		// TODO Auto-generated constructor stub
	public MyView(Context context, AttributeSet attrs) {
		super(context, attrs);
		context1=context;
		// TODO Auto-generated constructor stub
	}
	
	@Override
	protected void onDraw(Canvas canvas){
		super.onDraw(canvas);
		Paint paint=new Paint();
		paint.setColor(Color.RED);
		paint.setShadowLayer(2, 3, 4, Color.GRAY);
		Rect r=new Rect(40,40,200,100);
		canvas.drawRect(r,paint);
		paint.setColor(Color.BLUE);
	    canvas.drawText("自定义控件测试", 40, 40, paint);
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		// TODO Auto-generated method stub
		switch (event.getAction()){
		case MotionEvent.ACTION_DOWN:
			Toast.makeText(context1, "自定义组件测试",0).show();
			break;
		case MotionEvent.ACTION_MOVE:
			Toast.makeText(context1, "HUAHUA",0).show();
			break;
		}
		return super.onTouchEvent(event);
				
	}
 
}

接着，就可以像普通控件一样，在布局里声明使用（myview.xml）：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" 
    >
  <com.jtext.chessdisplay.MyView
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
      android:id="@+id/myView"  
      />  
</LinearLayout>

最后，在MainActivity里显示：

package com.jtext.chessdisplay;

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

public class MainActivity extends Activity {
    MyView2 mv;
    MyView2 mv1;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.myview);}
}

二、组合控件

以继承布局类来自定义控件为例.

布局myview2

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
  <ImageView 
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:id="@+id/iv"
      android:layout_gravity="center_vertical"/>
  <TextView 
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:id="@+id/tv"
      android:layout_gravity="center_vertical"
      android:gravity="center_horizontal"/>
</LinearLayout>

控件定义MyView2.java

package com.jtext.chessdisplay;

import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

public class MyView2 extends LinearLayout{
 private ImageView iv;
 private TextView tv;
 int i=0;
 Context context1;
	public MyView2(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
		LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);  
	    inflater.inflate(R.layout.myview2, this); 
	    iv=(ImageView) findViewById(R.id.iv);  
	    tv=(TextView)findViewById(R.id.tv);  
	    context1=context;
	    iv.setOnTouchListener(new myTouchListener());
	}
	public void setImageResource(int resid){
		iv.setImageResource(resid);
	}
	public void setTextView(String str,int color){
		tv.setText(str);
		tv.setTextColor(color);
	}
	class myTouchListener implements  OnTouchListener {

		@Override
		public boolean onTouch(View v, MotionEvent event) {
			// TODO Auto-generated method stub
			switch (v.getId()){
			case R.id.iv:
				i++;
				Toast.makeText(context1, "数量更改成功", 0).show();
			    tv.setText(i+"");;
				break;
			}
			return false;
		}
		
	}
}

MainActivity里进行显示：

package com.jtext.chessdisplay;

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

public class MainActivity extends Activity {
    MyView2 mv;
    MyView2 mv1;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.myview3);
		mv=(MyView2)findViewById(R.id.mv);
		mv1=(MyView2)findViewById(R.id.mv1);
		mv.setImageResource(R.drawable.cart);
		mv.setTextView("测试", Color.RED);
		mv1.setImageResource(R.drawable.cart);
		mv1.setTextView("测试", Color.BLUE);
	}
}