自定义组件-跟随手指的小球
自定义组件DrawView类
package com.muzao.drawview;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.View;
public class DrawView extends View{
public float currentX = 40;
public float currentY = 50;
public DrawView(Context context)
{
super(context);
}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
Paint p = new Paint();
p.setColor(Color.BLUE);
canvas.drawCircle(currentX, currentY, 15, p);
}
}DrawViewActivity类
package com.muzao.drawview;
import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.LinearLayout;
public class DrawViewActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LinearLayout layout = (LinearLayout)findViewById(R.id.main_layout);
final DrawView dv = new DrawView(this);
dv.setMinimumWidth(300);
dv.setMinimumHeight(500);
dv.setOnTouchListener(new OnTouchListener(){
public boolean onTouch(View arg0, MotionEvent arg1) {
// TODO Auto-generated method stub
//修改dv组件的currentX、currentY两个属性
dv.currentX = arg1.getX();
dv.currentY = arg1.getY();
//通知dv组件重绘
dv.invalidate();
return true;
}
});
layout.addView(dv);
}
}Graphic User Interface main.xml :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:id="@+id/main_layout"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello" />
</LinearLayout>
