It was a man who went down Layer 4 [Layer 4] -- Crazy greedy snake (1). Suddenly there was the fourth layer of the day.

It was a man who went down Layer 4 [Layer 4] -- Crazy greedy snake (1). Suddenly there was the fourth layer of the day.

Snake is a classic game. These classic games have added a lot of fun to our childhood. Today, we start to implement a Snake Game On Android devices step by step, I am also writing this game for the first time. I may make mistakes or take a detour, but I hope to have a good result. Next, let's explore the stone development step by step.

1. Create a project
Ii. Custom View (snake Interface)

package com.example.crazysnake;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.RectF;import android.util.AttributeSet;import android.view.View;public class MySnake extends View {private Paint paint;private RectF rect;public MySnake(Context context, AttributeSet attrs) {super(context, attrs);paint = new Paint();rect = new RectF();}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);rect.set(50, 50, 90, 90);paint.setColor(Color.RED);canvas.drawRect(rect, paint);}}

Layout File

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" ><com.example.crazysnake.MySnake     android:layout_width="match_parent"    android:layout_height="match_parent"/></LinearLayout>

Running Effect: we drew a small square on the interface, which is the basis for us to complete the snake (as important as building bricks) 3. Draw a colored snake and create a square object first

package com.example.crazysnake;public class Box {private int x;private int y;public Box(int x, int y) {super();this.x = x;this.y = y;}public int getX() {return x;}public void setX(int x) {this.x = x;}public int getY() {return y;}public void setY(int y) {this.y = y;}}

Draw a line of squares

package com.example.crazysnake;import java.util.ArrayList;import java.util.List;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.RectF;import android.util.AttributeSet;import android.view.View;public class MySnake extends View {private Paint paint;private RectF rect;private int boxSize = 30;private List<Box> boxs = new ArrayList<Box>();private static final int[] colors = {Color.RED,Color.BLUE, Color.GREEN,Color.YELLOW};public MySnake(Context context, AttributeSet attrs) {super(context, attrs);paint = new Paint();rect = new RectF();initData();}private void initData(){Box box;for(int i=0; i<10; i++){box = new Box(i*boxSize, 0);boxs.add(box);}}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);for(int i=0; i<boxs.size(); i++){paint.setColor(colors[i % colors.length]);rect.set(boxs.get(i).getX(), boxs.get(i).getY(), boxs.get(i).getX() + boxSize, boxSize);canvas.drawRect(rect, paint);}}}

4. Let the color snake move and rewrite the onTouchEvent Method

@Overridepublic boolean onTouchEvent(MotionEvent event) {System.out.println("onTouch");switch (event.getAction()) {case MotionEvent.ACTION_DOWN:mDownX = event.getX();mDownY = event.getY();break;case MotionEvent.ACTION_UP:float disX = event.getX() - mDownX;float disY = event.getY() - mDownY;System.out.println("disX = " + disX);System.out.println("dixY = " + disY);if(Math.abs(disX) > Math.abs(disY)){if(disX > 0){System.out.println("right");move(Derectory.RIGHT);}else{move(Derectory.LEFT);}}else{if(disY > 0){}else{}}break;}return true;}

Move method to move in the direction

private void move(Derectory derectory){Box box;int bs = 0;switch (derectory) {case LEFT:case TOP:bs = - boxSize;break;case RIGHT:case BOTTOM:bs = boxSize;break;}if(derectory == Derectory.LEFT || derectory == Derectory.RIGHT){for(int i=0; i<boxs.size(); i++){box = boxs.get(i);box.setX(box.getX() + bs);}}else{for(int i=0; i<boxs.size(); i++){box = boxs.get(i);box.setY(box.getY() + bs);}}invalidate();}

In the above Code, we do not control the boundary. We need to add code to judge the boundary condition. 5. Let the snake run automatically. Let's control it to start a thread and let the snake run automatically.

private class SnakeThread extends Thread{private boolean stoped = false;@Overridepublic void run() {while(!stoped){try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}move();postInvalidate();}}}

The Code is as follows:

package com.example.crazysnake;import java.util.ArrayList;import java.util.List;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.RectF;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;public class MySnake extends View {private Paint paint;private RectF rect;private int boxSize = 30;private SnakeThread snakeThread;private List<Box> boxs = new ArrayList<Box>();private static final int[] colors = {Color.RED,Color.BLUE, Color.GREEN,Color.YELLOW};private enum Derectory{LEFT,RIGHT,TOP,BOTTOM;}private Derectory currentDerect = Derectory.RIGHT;public MySnake(Context context, AttributeSet attrs) {super(context, attrs);paint = new Paint();rect = new RectF();initData();startThread();}public void startThread(){if(snakeThread == null){snakeThread = new SnakeThread();snakeThread.start();}}private void initData(){Box box;for(int i=0; i<10; i++){box = new Box(i*boxSize, 0);boxs.add(box);}}private float mDownX;private float mDownY;@Overridepublic boolean onTouchEvent(MotionEvent event) {System.out.println("onTouch");switch (event.getAction()) {case MotionEvent.ACTION_DOWN:mDownX = event.getX();mDownY = event.getY();break;case MotionEvent.ACTION_UP:float disX = event.getX() - mDownX;float disY = event.getY() - mDownY;System.out.println("disX = " + disX);System.out.println("dixY = " + disY);if(Math.abs(disX) > Math.abs(disY)){if(disX > 0){currentDerect = Derectory.RIGHT;}else{currentDerect = Derectory.LEFT;}}else{if(disY > 0){currentDerect = Derectory.BOTTOM;}else{currentDerect = Derectory.TOP;}}break;}return true;}private class SnakeThread extends Thread{private boolean stoped = false;@Overridepublic void run() {while(!stoped){try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}move();postInvalidate();}}}private void move(){Box box;if(boxs.get(0).getX() - boxSize < 0) {currentDerect = Derectory.RIGHT;}if(boxs.get(boxs.size() - 1).getX() + 2 * boxSize > getWidth()){currentDerect = Derectory.LEFT;}switch (currentDerect) {case LEFT:for(int i=0; i<boxs.size(); i++){box = boxs.get(i);box.setX(box.getX() - boxSize);}break;case RIGHT:for(int i=0; i<boxs.size(); i++){box = boxs.get(i);box.setX(box.getX() + boxSize);}break;case TOP:break;case BOTTOM:break;}}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);for(int i=0; i<boxs.size(); i++){paint.setColor(colors[i % colors.length]);rect.set(boxs.get(i).getX(), boxs.get(i).getY(), boxs.get(i).getX() + boxSize, boxSize);canvas.drawRect(rect, paint);}}}

Come here today, and continue tomorrow... ^-^