代码简单画圆

package com.example.Demo1;

import com.example.Demo1.R;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.os.Bundle;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.LinearLayout.LayoutParams;

public class MainActivity extends Activity {
private LinearLayout layout;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

layout = (LinearLayout) findViewById(R.id.rootLayout);

MyView myView1 = new MyView(this, 100, 100, 60);
// 设置颜色
myView1.setColor(Color.BLACK);

// 将自定义控件添加到布局中
layout.addView(myView1);

}

public class MyView extends View {
private float m_cx;
private float m_cy;
private float m_radius;
private Paint paint;

/**
*
* @param context
*            上下文
* @param cx
*            x轴
* @param cy
*            y轴
* @param radius
*            半径
*/
public MyView(Context context, float cx, float cy, float radius) {
super(context);
m_cx = cx;
m_cy = cy;
m_radius = radius;

// 首先定义一个paint（画笔）
paint = new Paint();

// 绘制矩形区域-实心矩形
// 设置画笔的颜色
paint.setColor(Color.BLACK);
// 设置样式-填充
paint.setStyle(Style.FILL);
}

public void setColor(int color) {
// 设置颜色
paint.setColor(color);
}

// 画布
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
// draw circle
canvas.drawCircle(m_cx, m_cy, m_radius, paint);
}

}
}