通过自定义view替代layout.xml表示activity的界面

 1 package com.example.activity_view;
 2 
 3 import android.content.Context;
 4 import android.graphics.Canvas;
 5 import android.graphics.Color;
 6 import android.graphics.Paint;
 7 import android.view.View;
 8 
 9 public class contentview extends View{
10 
11     public contentview(Context context) {
12         super(context);
13         // TODO Auto-generated constructor stub
14     }
15     @Override
16     protected void onDraw(Canvas canvas)
17     {
18         Paint paint=new Paint();
19         paint.setTextSize(18);
20         paint.setAntiAlias(true);                  //设置抗锯齿
21         paint.setColor(Color.RED);                 //设置字体颜色
22         canvas.drawText("这是通过继承和扩展view类来显示的。", 0, 50, paint);   //绘制字体
23     }
24 
25 }

package com.example.activity_view;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
    @Override
    public void  onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        contentview cv=new contentview(this);
        setContentView(cv);
    }

}