問題描述

研究了好久 都寫不好 。。。

package com.li.zhuoyuan.designmodel;import android.content.Context;import android.os.Build;import android.util.Log;import android.view.MotionEvent;import android.view.ScaleGestureDetector;public abstract class GestureDetector { private static final String TAG = 'VersionedGestureDetector'; OnGestureListener mListener; public static GestureDetector newInstance(Context context, OnGestureListener listener) {final int sdkVersion = Integer.parseInt(Build.VERSION.SDK);GestureDetector detector = null;if (sdkVersion < Build.VERSION_CODES.ECLAIR) { detector = new CupcakeDetector();} else if (sdkVersion < Build.VERSION_CODES.FROYO) { detector = new EclairDetector();} else { detector = new FroyoDetector(context);}Log.d(TAG, 'Created new ' + detector.getClass());detector.mListener = listener;return detector; } public abstract boolean onTouchEvent(MotionEvent ev); public interface OnGestureListener {public void onDrag(float dx, float dy);public void onScale(float scaleFactor); } private static class CupcakeDetector extends GestureDetector {float mLastTouchX;float mLastTouchY;float getActiveX(MotionEvent ev) { return ev.getX();}float getActiveY(MotionEvent ev) { return ev.getY();}boolean shouldDrag() { return true;}@Overridepublic boolean onTouchEvent(MotionEvent ev) { switch (ev.getAction()) {case MotionEvent.ACTION_DOWN: { mLastTouchX = getActiveX(ev); mLastTouchY = getActiveY(ev); break;}case MotionEvent.ACTION_MOVE: { final float x = getActiveX(ev); final float y = getActiveY(ev); if (shouldDrag()) {mListener.onDrag(x - mLastTouchX, y - mLastTouchY); } mLastTouchX = x; mLastTouchY = y; break;} } return true;} } private static class EclairDetector extends CupcakeDetector {private static final int INVALID_POINTER_ID = -1;private int mActivePointerId = INVALID_POINTER_ID;private int mActivePointerIndex = 0;@Overridefloat getActiveX(MotionEvent ev) { return ev.getX(mActivePointerIndex);}@Overridefloat getActiveY(MotionEvent ev) { return ev.getY(mActivePointerIndex);}@Overridepublic boolean onTouchEvent(MotionEvent ev) { final int action = ev.getAction(); //No.1 //開始寫代碼，請結合所有代碼在這里實現，計算手指在屏幕上移動的位置。從而方便其他調用這個類的地方更新屏幕上小機器人的位置。小機器人跟隨手指移動。 switch (action & MotionEvent.ACTION_MASK) {case MotionEvent.ACTION_DOWN: mLastTouchX = ev.getX(); mLastTouchY = ev.getY(); break;case MotionEvent.ACTION_MOVE: mLastTouchX = ev.getX(); mLastTouchY = ev.getY(); } mActivePointerIndex = 0; //end_code return super.onTouchEvent(ev);} } private static class FroyoDetector extends EclairDetector {private ScaleGestureDetector mDetector;public FroyoDetector(Context context) { mDetector = new ScaleGestureDetector(context, new ScaleGestureDetector.SimpleOnScaleGestureListener() {@Overridepublic boolean onScale(ScaleGestureDetector detector) { mListener.onScale(detector.getScaleFactor()); return true;} });}@Overrideboolean shouldDrag() { return !mDetector.isInProgress();}@Overridepublic boolean onTouchEvent(MotionEvent ev) { mDetector.onTouchEvent(ev); return super.onTouchEvent(ev);} }}

package com.li.zhuoyuan.designmodel;import android.graphics.Bitmap;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.MotionEvent;import android.view.View;import android.widget.Button;import android.widget.ImageView;import android.widget.Toast;import java.io.File;public class MainActivity extends AppCompatActivity { private Button button_save, button_resume; private ImageView iv_canvas; private Bitmap baseBitmap; private Canvas canvas; /*聲明畫筆*/ private Paint mPaint; /*手勢監聽器*/ private View.OnTouchListener onTouchListener = new View.OnTouchListener() {/*表示手指在屏幕上X軸Y軸的坐標點*/float startX;float startY;@Overridepublic boolean onTouch(View v, MotionEvent event) { switch (event.getAction()) {case MotionEvent.ACTION_DOWN: //No.1 //開始寫代碼，請用代碼實現初始化Bitmap對象、定義畫布顏色（請定義為白色）、記錄用戶手指在屏幕上的觸摸點坐標 將坐標存入到startX和startY變量中。 Bitmap bitmap = Bitmap.createBitmap(iv_canvas.getWidth(), iv_canvas.getHeight(), Bitmap.Config.ARGB_8888); mPaint.setColor(Color.WHITE); startX = iv_canvas.getX(); startX = iv_canvas.getY(); //end_code break;case MotionEvent.ACTION_MOVE: //No.2 //開始寫代碼，根據手指在屏幕滑動的軌跡實現繪制軌跡的線條，并更新手指在屏幕上的坐標點（startX和startY變量），將繪制好的圖像展示在ImageView中。 float stopX = iv_canvas.getX(); float stopY = iv_canvas.getY(); //end_code break;case MotionEvent.ACTION_UP: break;default: break; } return true;} }; @Override protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);/*初始化畫筆 設置畫筆的寬度和顏色*/mPaint = new Paint();mPaint.setStrokeWidth(5);mPaint.setColor(Color.RED);iv_canvas = (ImageView) findViewById(R.id.iv_canvas);button_save = (Button) findViewById(R.id.button_save);button_resume = (Button) findViewById(R.id.button_resume);/*保存按鈕的監聽器*/button_save.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) {saveBitmap(); }});/*清除按鈕的監聽器*/button_resume.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) {resumeCanvas(); }});iv_canvas.setOnTouchListener(onTouchListener); } /*保存圖片的方法*/ protected void saveBitmap() {try { /*以png的格式保存的手機內存中*/ //No.3 //開始寫代碼，請在這里實現文件存儲的方法，將手指在屏幕上涂鴉的圖形以PNG圖片的形式保存到SD卡中；并發送廣播進行掃描SD卡。 File file //end_code} catch (Exception e) { Toast.makeText(MainActivity.this, '保存圖片失敗', 0).show(); e.printStackTrace();} } /*清除畫布的方法*/ protected void resumeCanvas() {if (baseBitmap != null) { baseBitmap = Bitmap.createBitmap(iv_canvas.getWidth(), iv_canvas.getHeight(), Bitmap.Config.ARGB_8888); canvas = new Canvas(baseBitmap); canvas.drawColor(Color.WHITE); iv_canvas.setImageBitmap(baseBitmap); Toast.makeText(MainActivity.this, '清除畫板成功，可以重新開始繪圖', 0).show();} }}

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問題解答

直接說要做個什么功能比較好，這樣估計沒人回去幫你填代碼

能把你的工資分我一份嗎？