标签：android应用
package com.example.path3;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
/*实现：采用双缓冲实现画图板*/
public class DrawView extends View {
float preX;
float preY;
private Path path;
public Paint paint=null;
final int VIEW_WIDTH = 320;
final int VIEW_HEIGHT = 480;
Bitmap cacheBitmap = null; //定义一个内存中的图片，该图片将作为缓存区
Canvas cacheCanvas = null; //定义cacheCanvas上的Canvas对象
/*---------------------构造方法----------------------------*/
public DrawView(Context context, AttributeSet set)
{
super(context, set);
path = new Path();
//1.创建一个与该View相同大小的缓存区
cacheBitmap = Bitmap.createBitmap(VIEW_WIDTH, VIEW_HEIGHT, Config.ARGB_8888);
//2.设置cacheCanvas将会绘制到内存中的cacheBitmap上
cacheCanvas = new Canvas();
cacheCanvas.setBitmap(cacheBitmap);
//3.设置画笔(颜色、风格、反锯齿)
paint = new Paint(Paint.DITHER_FLAG); //创建画笔
paint.setColor(Color.RED); //画笔颜色为红色
paint.setStyle(Paint.Style.STROKE); //设置画笔风格
paint.setAntiAlias(true); //反锯齿
paint.setDither(true);
}
/*---------------------监听触摸事件----------------------------*/
@Override
public boolean onTouchEvent(MotionEvent event)
{
//获取拖动事件的发生位置
float x = event.getX();
float y = event.getY();
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN:
path.moveTo(x, y);
preX = x;
preY = y;
break;
case MotionEvent.ACTION_MOVE:
path.quadTo(preX, preY, x, y);
preX = x;
preY = y;
break;
case MotionEvent.ACTION_UP:
cacheCanvas.drawPath(path, paint); //沿着路径绘制图形存放到cacheBitmap中
path.reset();
break;
}
invalidate();
return true; //返回true表明处理方法已经处理该事件
}
// /*--------------------绘图-------------------------*/
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Paint bmpPaint = new Paint();
//a.将cacheBitmap绘制到该View组件上
canvas.drawBitmap(cacheBitmap, 0, 0, bmpPaint);
//b.沿着path绘制
canvas.drawPath(path, paint);
}
}package com.example.path3;
import android.graphics.BlurMaskFilter;
import android.graphics.Color;
import android.graphics.EmbossMaskFilter;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
public class HandDraw extends ActionBarActivity {
EmbossMaskFilter emboss;
BlurMaskFilter blur;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
emboss = new EmbossMaskFilter(new float[] {1.5f,1.5f,1.5f}, 0.6f, 6,4.2f);
blur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);
}
//装载R.menu.hand_draw对应的菜单并添加到menu中
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.hand_draw, menu);
return true;
}
//菜单被单击后的回调方法
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
DrawView dv = (DrawView)findViewById(R.id.draw);
//判断单击的是哪个菜单项并有针对性地作出响应
switch(id)
{
//颜色设置
case R.id.red: //红色
dv.paint.setColor(Color.RED);
item.setChecked(true);
break;
case R.id.green: //绿色
dv.paint.setColor(Color.GREEN);
item.setChecked(true);
break;
case R.id.blue: //红色
dv.paint.setColor(Color.BLUE);
item.setChecked(true);
break;
//画笔大小设置
case R.id.width_1: //号画笔
dv.paint.setStrokeWidth(1);
break;
case R.id.width_2: //号画笔
dv.paint.setStrokeWidth(2);
break;
case R.id.width_5: //号画笔
dv.paint.setStrokeWidth(5);
break;
//模糊效果
case R.id.blur:
dv.paint.setMaskFilter(blur);
break;
//浮雕效果
case R.id.emboss:
dv.paint.setMaskFilter(emboss);
break;
}
return super.onOptionsItemSelected(item);
}
}<menu xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" tools:context="com.example.path3.HandDraw" > <!-- 定义一组颜色选项菜单项 --> <item android:title="@string/color"> <menu> <group android:checkableBehavior="single"> <item android:id="@+id/red" android:title="@string/color_red"/> <item android:id="@+id/green" android:title="@string/color_green"/> <item android:id="@+id/blue" android:title="@string/color_blue"/> </group> </menu> </item> <!-- 定义一组笔触大小选项菜单项 --> <item android:title="@string/width"> <menu> <group android:checkableBehavior="single"> <item android:id="@+id/width_1" android:title="@string/width1"/> <item android:id="@+id/width_2" android:title="@string/width2"/> <item android:id="@+id/width_5" android:title="@string/width5"/> </group> </menu> </item> <!-- --> <item android:id="@+id/blur" android:title="@string/blur"/> <!-- 定义一组宽度选项菜单项 --> <item android:id="@+id/emboss" android:title="@string/emboss"/> </menu>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.example.path3.HandDraw" > <com.example.path3.DrawView android:id="@+id/draw" android:layout_width="wrap_content" android:layout_height="wrap_content" android:width="320px" android:height="480px" /> </RelativeLayout>
<?xml version="1.0" encoding="utf-8"?> <resources> <string name="app_name">简易画板</string> <string name="color">选择颜色</string> <string name="color_red">红色</string> <string name="color_green">绿色</string> <string name="color_blue">蓝色</string> <string name="width">画笔大小</string> <string name="width1">1号画笔</string> <string name="width2">2号画笔</string> <string name="width5">3号画笔</string> <string name="blur">模糊效果</string> <string name="emboss">浮雕效果</string> </resources>
标签：android应用
原文地址：http://blog.csdn.net/u012637501/article/details/43484505
