Android 的布局文件在layout下面，通常命名为*.xml。通过在XML中以XML的形式定义View，但是Android应用程序中经常需要自定义View，这就需要一个继承自Android View 的类。今天写了一个小游戏，鼠标移动的时候，View里面的红色圆球随着鼠标的移动而移动。
UserDefineViewActivity.java
package com.example.androidexample;
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 UserDefineViewActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_draw);
LinearLayout layout = (LinearLayout)findViewById(R.id.DrawLayout);
final DrawView drawView = new DrawView(this);
layout.setMinimumHeight(500);
layout.setMinimumWidth(300);
drawView.setOnTouchListener(new OnTouchListener(){
@Override
public boolean onTouch(View view, MotionEvent event) {
// TODO Auto-generated method stub
drawView.currentX = event.getX();
drawView.currentY = event.getY();
drawView.invalidate();
return true;
}
});
layout.addView(drawView);
}
}
下面是继承自Android View 的类
package com.example.androidexample;
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;
public float currentY;
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
Paint paint = new Paint();
paint.setColor(Color.RED);
canvas.drawCircle(currentX, currentY, 15, paint);
}
public DrawView(Context context) {
super(context);
// TODO Auto-generated constructor stub
}
}
界面布局文件activity_draw.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/DrawLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
</LinearLayout>
注意：不要忘记将UserDefineViewActivity注册到AndroidManifest.xml
运行效果
原文：http://www.cnblogs.com/fuhui-jurassic/p/4129451.html