Android一个画图的例子，希望对画图初学者有帮助

1.Activity

package com.fit.shap;

import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.LinearLayout;

public class MainActivity extends Activity {

/** Called when the activity is first created. */

private boolean autoFlag=false;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

LinearLayout root=(LinearLayout) findViewById(R.id.root);

final MyShap view=new MyShap(this);

root.addView(view);

Button line=(Button) findViewById(R.id.line);

line.setOnClickListener(new OnClickListener() {

public void onClick(View v) {

view.setFlag(1);

view.invalidate();

}

});

Button squre=(Button) findViewById(R.id.squre);

squre.setOnClickListener(new OnClickListener() {

public void onClick(View v) {

view.setFlag(2);

view.invalidate();

}

});

Button text=(Button) findViewById(R.id.text);

text.setOnClickListener(new OnClickListener() {

public void onClick(View v) {

view.setFlag(3);

view.invalidate();

}

});

Button auto=(Button) findViewById(R.id.auto);

auto.setOnClickListener(new OnClickListener() {

public void onClick(View v) {

if(autoFlag){

view.stopDraw();

}else{

view.runDraw();

}

autoFlag=!autoFlag;

}

});

}

}

2.画图过程

package com.fit.shap;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Rect;

import android.view.View;

public class MyShap extends View {

private int flag=-1;

private Thread auto=null;

private boolean autoFlag=false;

public MyShap(Context context) {

super(context);

}

public void setFlag(int f){

this.flag=f;

}

public void runDraw(){

autoFlag=true;

auto=new Thread(){

@Override

public void run() {

int f=0;

while(autoFlag){

f++;

if(f>3){

f=1;

}

setFlag(f);

postInvalidate();

try {

Thread.sleep(500);

} catch (InterruptedException e) {

e.printStackTrace();

}

}

}

};

auto.start();

}

public void stopDraw(){

autoFlag=false;

}

@Override

protected void onDraw(Canvas canvas) {

//定义一个画笔

Paint paint=new Paint();

paint.setAntiAlias(true);

//画笔颜色

paint.setColor(Color.GRAY);

//画板

canvas.drawRect(new Rect(0,0,320,320), paint);

switch(flag){

case 1:

paint.setColor(Color.YELLOW);

canvas.drawLine(20, 20, 240,250, paint);

break;

case 2:

paint.setColor(Color.GREEN);

canvas.drawRect(new Rect(30,30, 240,240), paint);

break;

case 3:

paint.setColor(Color.BLUE);

canvas.drawText("这是我的文本！！",20,200, paint);

break;

}

}

}