<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main"  android:layout_width="match_parent" android:layout_height="match_parent"  tools:context="com.example.demo.MainActivity">  <ImageView    android:id="@+id/iv"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:src="@drawable/bg"    />  <LinearLayout    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:orientation="horizontal"    android:layout_alignParentBottom="true"    >    <Button      android:id="@+id/red"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:text="紅色"      android:onClick="onplay"      />    <Button      android:id="@+id/green"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:text="綠色"      android:onClick="onplay"      />    <Button      android:id="@+id/root"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:text="刷子"      android:onClick="onplay"      />    <Button      android:id="@+id/save"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:text="保存"      android:onClick="onplay"      />    <Button      android:id="@+id/finish"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:text="涂漆"      android:onClick="onplay"      />  </LinearLayout></RelativeLayout>

/*畫(huà)板canvas  畫(huà)板paint 手勢(shì)識(shí)別器整體思路:因?yàn)槲沂菆D片是作畫(huà),實(shí)際是對(duì)圖片進(jìn)行修改,起到畫(huà)圖的效果1.原圖,白紙,畫(huà)筆,畫(huà)板2.根據(jù)手勢(shì)識(shí)別進(jìn)行作畫(huà) */public class MainActivity extends AppCompatActivity {private Bitmap bitmap;  private Canvas canvas;private ImageView iv;  private int startx;  private int starty;  private Paint paint;  private Bitmap bmSrc;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    //加載原圖    bmSrc = BitmapFactory.decodeResource(getResources(), R.drawable.bg);    //創(chuàng)建白紙,寬,高,圖片的參數(shù)     bitmap = Bitmap.createBitmap(bmSrc.getWidth(), bmSrc.getHeight(), bmSrc.getConfig());    //創(chuàng)建畫(huà)板,參數(shù)是白紙對(duì)象    canvas = new Canvas(bitmap);    //創(chuàng)建畫(huà)筆    paint = new Paint();    //在紙上作畫(huà)    iv=(ImageView)findViewById(R.id.iv);    canvas.drawBitmap(bmSrc,new Matrix(), paint);    //-----------------手勢(shì)識(shí)別器和畫(huà)筆結(jié)合的知識(shí)-------------------  //給控件設(shè)置手勢(shì)適配器,可以得到用戶在這個(gè)控件上所做的手勢(shì)    iv.setOnTouchListener(new View.OnTouchListener() {      //當(dāng)用戶手在這個(gè)控件時(shí),指的就是用戶的手對(duì)控件滑動(dòng),按下,松開(kāi)的三種場(chǎng)景,自動(dòng)回調(diào)      @Override      public boolean onTouch(View view, MotionEvent motionEvent) {        switch (motionEvent.getAction()){          case MotionEvent.ACTION_DOWN://按下時(shí)回調(diào)一次            //獲取用戶手指按下時(shí)的坐標(biāo)            startx = (int) motionEvent.getX();            starty = (int) motionEvent.getY();            break;          case MotionEvent.ACTION_MOVE://手指滑動(dòng)時(shí),不停地調(diào)用            int newx = (int) motionEvent.getX();            int newy = (int) motionEvent.getY();            //在背景圖畫(huà)線            canvas.drawLine(startx,starty,newx,newy, paint);            startx=newx;            starty=newy;            iv.setImageBitmap(bitmap);            break;          case MotionEvent.ACTION_UP://松開(kāi)時(shí)回調(diào)一次            break;        }        //事情分發(fā)機(jī)制        //true:iv處理該觸摸事件        //false:iv不處理該觸摸事件,事件傳遞給上一級(jí)        return true;      }    });  }  public void onplay(View view){   switch (view.getId()){     case R.id.red:       paint.setColor(Color.RED);       break;     case R.id.green:       paint.setColor(Color.GREEN);       break;     case R.id.root:       paint.setStrokeWidth(5);       break;     case R.id.save:       if(SaveViewUtil.saveScreen(iv)){         Toast.makeText(this, "截圖成功", Toast.LENGTH_SHORT).show();       }else{         Toast.makeText(this, "截圖失敗，請(qǐng)檢查sdcard是否可用", Toast.LENGTH_SHORT).show();       }       break;     //涂漆     case R.id.finish:       canvas.drawRect(new Rect(0,0,width,height), paint);       break;     }   }  }

public class SaveViewUtil {    private static final File rootDir = new File(Environment.getExternalStorageDirectory()+File.separator);  /**保存截圖的方法*/  public static boolean saveScreen(View view){   //判斷sdcard是否可用   if(!Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())){     return false;   }   if(!rootDir.exists()){     rootDir.mkdir();   }   view.setDrawingCacheEnabled(true);   view.buildDrawingCache();   Bitmap bitmap = view.getDrawingCache();   try {     bitmap.compress(CompressFormat.JPEG, 100, new FileOutputStream(new File(rootDir,System.currentTimeMillis()+".jpg")));     return true;   } catch (FileNotFoundException e) {     e.printStackTrace();     return false;   }finally{     view.setDrawingCacheEnabled(false);     bitmap = null;   }  }}<!-- 往SDCard寫(xiě)入數(shù)據(jù)權(quán)限 --><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>