Android画图demo
16lz
2021-01-24
如何在图片上画画呢？这里写了一个demo，供大家参考
一、先看一眼工程结构
工程结构：
二、自定义view
这个自定义view实现了保留轨迹的功能，代码如下package picturegame.view;import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Paint.Style;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import com.winton.picturegame.R;public class GameView extends View{private Paint paint = null; //private Bitmap originalBitmap = null;//原始图private Bitmap new1Bitmap = null;private Bitmap new2Bitmap = null;private float clickX =0;private float clickY=0;private float startX=0;private float startY=0;private boolean isMove = true;private boolean isClear = false;private int color =Color.RED;//默认画笔颜色为红色private float strokeWidth =2.0f;//默认画笔粗度public GameView(Context context) {this(context,null);// TODO Auto-generated constructor stub}public GameView(Context context,AttributeSet atts) {this(context,atts,0);// TODO Auto-generated constructor stub}public GameView(Context context,AttributeSet atts,int defStyle) {super(context,atts,defStyle);// TODO Auto-generated constructor stuboriginalBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.default_pic).copy(Bitmap.Config.ARGB_8888, true);//加载一张背景new1Bitmap=originalBitmap.createBitmap(originalBitmap);}//清除函数public void clear(){isClear =true;new2Bitmap=originalBitmap.createBitmap(originalBitmap);invalidate();//重载}public void setStrokeWidth(float width){this.strokeWidth=width;initPaint();}@Overrideprotected void onDraw(Canvas canvas) {// TODO Auto-generated method stubsuper.onDraw(canvas);canvas.drawBitmap(writer(new1Bitmap),0,0, null);}@Overridepublic boolean onTouchEvent(MotionEvent event) {// TODO Auto-generated method stubclickX =event.getX();clickY=event.getY();if(event.getAction()==MotionEvent.ACTION_DOWN){isMove =false;invalidate();return true;}else if(event.getAction()==MotionEvent.ACTION_MOVE){isMove =true;invalidate();return true;}return super.onTouchEvent(event);}/** * @Title: writer * @Description: TODO(生成bitmap) * @param @param pic* @param @return 设定文件 * @return Bitmap 返回类型 * @throws */public Bitmap writer(Bitmap pic){initPaint();Canvas canvas =null;if(isClear){canvas=new Canvas(new2Bitmap);}else{canvas=new Canvas(pic);}if(isMove){canvas.drawLine(startX, startY, clickX, clickY, paint);//划线}startX = clickX;startY =clickY;if(isClear){return new2Bitmap;}return pic;}private void initPaint(){paint = new Paint();//新建画笔paint.setStyle(Style.STROKE);//设置为画线paint.setAntiAlias(true);//可以让线条圆滑一些paint.setColor(color);//设置画笔颜色paint.setStrokeWidth(strokeWidth);//设置画笔线条的粗细}/** * @Title: setColor * @Description: TODO(设置线条颜色的对外接口) * @param @param color 设定文件 * @return void 返回类型 * @throws */public void setColor(int color){this.color=color;initPaint();}} 三、主页面布局文件
主页面布局文件<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center_horizontal" android:orientation="vertical" > <LinearLayout android:layout_width="match_parent" android:layout_height="50dp" android:orientation="horizontal" > <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center" > <TextView android:id="@+id/tv_30" android:layout_width="30dp" android:layout_height="30dp" android:background="@drawable/bg_notifaction" /> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center" > <TextView android:id="@+id/tv_25" android:layout_width="25dp" android:layout_height="25dp" android:background="@drawable/bg_notifaction" /> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center" > <TextView android:id="@+id/tv_20" android:layout_width="20dp" android:layout_height="20dp" android:background="@drawable/bg_notifaction" /> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center" > <TextView android:id="@+id/tv_15" android:layout_width="15dp" android:layout_height="15dp" android:background="@drawable/bg_notifaction" /> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center" > <TextView android:id="@+id/tv_10" android:layout_width="10dp" android:layout_height="10dp" android:background="@drawable/bg_notifaction" /> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center" > <TextView android:id="@+id/tv_5" android:layout_width="5dp" android:layout_height="5dp" android:background="@drawable/bg_notifaction" /> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center" > <TextView android:id="@+id/tv_2" android:layout_width="2dp" android:layout_height="2dp" android:background="@drawable/bg_notifaction" /> </LinearLayout> </LinearLayout> <picturegame.view.GameView android:layout_width="match_parent" android:layout_height="300dp" android:id="@+id/gameview" /> <Button android:layout_width="200dp" android:layout_height="80dp" android:text="clear" android:textColor="@color/black" android:id="@+id/btn_clear" /></LinearLayout>
四、主Activity代码
package com.winton.picturegame;import picturegame.view.GameView;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.TextView;import com.winton.basemodule.BaseActivity;public class MainActivity extends BaseActivity implements OnClickListener {private GameView gameview = null;private Button clear = null;private TextView tv30,tv25,tv20,tv15,tv10,tv5,tv2;@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);}@Overridepublic void initView() {// TODO Auto-generated method stubsetContentView(R.layout.activity_main);gameview=(GameView)findViewById(R.id.gameview);clear =(Button)findViewById(R.id.btn_clear);tv30=(TextView)findViewById(R.id.tv_30);tv25=(TextView)findViewById(R.id.tv_25);tv20=(TextView)findViewById(R.id.tv_20);tv15=(TextView)findViewById(R.id.tv_15);tv10=(TextView)findViewById(R.id.tv_10);tv5=(TextView)findViewById(R.id.tv_5);tv2=(TextView)findViewById(R.id.tv_2);}@Overridepublic void initListener() {// TODO Auto-generated method stubclear.setOnClickListener(this);tv30.setOnClickListener(this);tv25.setOnClickListener(this);tv20.setOnClickListener(this);tv15.setOnClickListener(this);tv10.setOnClickListener(this);tv5.setOnClickListener(this);tv2.setOnClickListener(this);}@Overridepublic void initData() {// TODO Auto-generated method stub}@Overridepublic void onClick(View v) {// TODO Auto-generated method stubif(v==clear){gameview.clear();return;}if(v==tv30){gameview.setStrokeWidth(30f);return;}if(v==tv25){gameview.setStrokeWidth(25f);return;}if(v==tv20){gameview.setStrokeWidth(20f);return;}if(v==tv15){gameview.setStrokeWidth(15f);return;}if(v==tv10){gameview.setStrokeWidth(10f);return;}if(v==tv5){gameview.setStrokeWidth(5f);return;}if(v==tv2){gameview.setStrokeWidth(2f);return;}}} 五、效果
运行效果图如下六、疑问
当线条变粗时，线条会出现如上图中不连续的问题。请问高手这个怎么处理呢？我猜测应该要运行算法，但还不知道怎么运行。更多相关文章
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