绘制扇形

在main.xml中：

<LinearLayout

xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent"

android:layout_height="fill_parent">

<com.li.paintproject.MyView

android:layout_width="fill_parent"

android:layout_height="wrap_content"/>

</LinearLayout>

在MyPaintDemo.java中：

package com.li.paintproject;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.view.MenuItem;

import android.support.v4.app.NavUtils;

public class MyPaintDemo extends Activity {

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

}

}

在MyView.java中：

package com.li.paintproject;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Paint.Style;

import android.graphics.RectF;

import android.util.AttributeSet;

import android.view.View;

public class MyView extends View {

public MyView(Context context, AttributeSet attrs) {

super(context, attrs);

}

@Override

protected void onDraw(Canvas canvas) {

canvas.drawColor(Color.BLACK) ; // 画布为黑色

Paint paint = new Paint() ;

RectF oval = new RectF(); //浮点型的

paint.setColor(Color.YELLOW);

paint.setStyle(Style.STROKE); //空心的

oval = new RectF();

//扇形左上角坐标（80.0f,120.0f），右上角坐标（400.0f,200.0f）

oval.set(80.0f,80.0f,500.0f,500.0f);

canvas.drawArc(oval, 150.0f, 140.0f, true, paint);

}

}