区域实现Android实现图片的裁剪(不调用系统功能)

转载

mob604756ef7d06 2013-05-15 19:27:00

文章标签 android java ide sed xml 文章分类 代码人生

首先声明，我是一个菜鸟。一下文章中出现技术误导情况盖不负责

上一篇文章提及了通过调用系统相册或拍照来实现图片的缩放\裁剪。不过这对于笔者项目的

要求一样不适合,笔者需要的是通过对手机屏幕整个停止一个截图,并对这个截图停止裁剪操作。

依托系统功能确实可以实现图片的裁剪，但是不够灵巧。这里笔者供给一种较为灵巧的做法。

但是这种做法的用户体验没有上篇文章的好，至于使用何种方法，读者应该自己权衡。

一样，我们先看现实效果图。

这里展示的是笔者项目的一小部分(阅读器):

区域实现Android实现图片的裁剪(不调用系统功能)_java

我们点击左下角的剪切按钮

区域实现Android实现图片的裁剪(不调用系统功能)_java_02

我们通过红色边框的四个角来控制裁剪的大小,移动红色框体来控制裁剪的位置区域。

接下来我们看看源码的实现：

首先点击剪切按钮的时候，我们应该生成一个Bitmap对象，传递给另一个Activty处理

具体做法如下：

cutP.setOnClickListener(new View.OnClickListener() {     public void onClick(View v) {     //将一些按钮隐藏     cutP.setVisibility(View.INVISIBLE);     mTopBarSwitcher.setVisibility(View.INVISIBLE);     mPageSlider.setVisibility(View.INVISIBLE);     back.setVisibility(View.INVISIBLE);     mPageNumberView.setVisibility(View.INVISIBLE);     View view = MuPDFActivity.this.getWindow().getDecorView();     if (false == view.isDrawingCacheEnabled()) {      view.setDrawingCacheEnabled(true);     }     Bitmap bitmap = view.getDrawingCache();     ImageView imgv = new ImageView(MuPDFActivity.this);     imgv.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,       LayoutParams.FILL_PARENT-200));     imgv.setImageBitmap(bitmap);     backBitmap = bitmap;     //传递给另一个Activity停止裁剪     Intent intent = new Intent();     intent.setClass(MuPDFActivity.this, CutActivity.class);     startActivity(intent);     }       });

Tips：这里笔者是将这个截取的Bitmap对象传递给另一个Actvity做相干处理，这里如何

在Activity之间停止Bitmap传递呢？这里我们简略的应用java语法特性来实现具体做法如下：

我们在ActvityA中有一个public static Bitmap bitmap对象，当ActivityA跳转到B时，我们直接

通过ActivityA.bitmap来获得这个对象。

之后就是如何停止裁剪的操作了。操作在另一个Activity中停止。XML配置文件信息如下：

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="match_parent"     android:layout_height="match_parent"     >   <com.artifex.mupdf.Crop_Canvas     android:id="@+id/myCanvas"     android:layout_width="fill_parent"     android:layout_height="fill_parent"      android:background="#313131"      />     <Button          android:id="@+id/cutCancel"         android:layout_height="wrap_content"         android:layout_width="wrap_content"         android:text="取消"         android:layout_alignParentBottom="true"         android:layout_alignParentLeft="true"/>     <Button          android:id="@+id/cutEnsure"         android:layout_height="wrap_content"         android:layout_width="wrap_content"         android:text="肯定"         android:layout_alignParentBottom="true"         android:layout_centerInParent="true"/>     <Button          android:id="@+id/toPDF"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="ToPDF"         android:layout_alignParentBottom="true"         android:layout_alignParentRight="true"/> </RelativeLayout>

通过配置文件可以看到我们自定义了一个View(ImageView)其实现如下：

每日一道理

“多难兴才”曾一度被人定为规律。请看：屈原被放逐而作《离骚》；司马迁受宫刑而作《史记》；欧阳修两岁丧父笃学而成才；曹雪芹举家食粥而写出了不朽的《红楼梦》；越王勾践卧薪尝胆而雪洗国耻；韩信遭胯下辱而统率百万雄兵……他们都是在与逆境搏斗中成为伟人的！

package com.artifex.mupdf;  import android.content.Context; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Matrix; import android.graphics.Paint; import android.graphics.Rect; import android.graphics.RectF; import android.graphics.Bitmap.Config; import android.graphics.drawable.BitmapDrawable; import android.util.AttributeSet; import android.view.MotionEvent; import android.widget.ImageView;  public class Crop_Canvas extends ImageView {   private final static int PRESS_LB = 0;//表现左下角矩形框  private final static int PRESS_LT = 1;//表现左上角矩形框  private final static int PRESS_RB = 2;//表现右下角矩形框  private final static int PRESS_RT = 3;//表现右上角矩形框   private Bitmap bitMap = null;    //原始图片  private RectF src = null;     //经过比例转换后的裁剪区域  private RectF dst = null;     //图片显示区域，也就是drawBitmap函数中的目标dst  private RectF ChooseArea = null;    //选择区域      private Paint mPaint = null;    //画笔  private Matrix matrix = null;    //矩阵    private int mx = 0;       //存储触笔移动时，之前�?��的触笔的x坐标  private int my = 0;       //存储触笔移动时，之前�?��的触笔的y坐标  private boolean touchFlag = false;   //触笔是否在屏幕之�?  private boolean cutFlag = false;   //是否点击了menu上的裁剪按钮  private int recFlag = -1;     //用来存储触笔点击了哪个小矩形框（转变选择区域大小的小矩形框）  private boolean firstFlag = false;    private RectF recLT = null;     //左上角的小矩形框  private RectF recRT = null;     //右上角的小矩形框  private RectF recLB = null;     //左下角的小矩形框  private RectF recRB = null;     //右下角的小矩形框  private static final int LEFT_AREA_ALPHA = 50 * 255 / 100;  private RectF leftRectL = null;  private RectF leftRectR = null;  private RectF leftRectT = null;  private RectF leftRectB = null;  private Paint leftAreaPaint = null;    public Crop_Canvas(Context context, AttributeSet attrs) {   super(context, attrs);   this.init();  }    public Crop_Canvas(Context context) {   super(context);   this.init();  }     public void init(){   cutFlag = true;   recLT = new RectF();   recLB = new RectF();   recRT = new RectF();   recRB = new RectF();   dst = new RectF();   mPaint = new Paint();   mPaint.setColor(Color.RED);   mPaint.setStyle(Paint.Style.STROKE);      //将画笔的风格改成空心   ChooseArea = new RectF();   this.setPressRecLoc();   src = null;   firstFlag = true;      //选择框之外的灰色区域，分成四个矩形框      leftAreaPaint = new Paint();   leftAreaPaint.setStyle(Paint.Style.FILL);   leftAreaPaint.setAlpha(Crop_Canvas.LEFT_AREA_ALPHA);  }    public void setBitmap(Bitmap bitmap){   BitmapDrawable bd = new BitmapDrawable(bitmap);   src = new RectF(0,0,bd.getIntrinsicWidth(),bd.getIntrinsicHeight());   this.bitMap = bitmap.copy(Config.ARGB_8888, true);      this.setImageBitmap(bitMap);   leftRectB = new RectF();   leftRectL = new RectF();   leftRectR = new RectF();   leftRectT = new RectF();  }    public void imageScale(){   matrix = this.getImageMatrix();   matrix.mapRect(dst, src);   int padding = this.getPaddingBottom();   int width = bitMap.getWidth();   int height = bitMap.getHeight();   //dst.set(dst.left+padding,dst.top+padding,dst.right+padding,dst.bottom+padding);   dst.set(dst.left+20,dst.top+20,width-20,height - 40);   ChooseArea = new RectF(dst);   this.setPressRecLoc();  }    public Bitmap getSubsetBitmap(){   float ratioWidth = bitMap.getWidth()/(float)(dst.right-dst.left);   float ratioHeight = bitMap.getHeight()/(float)(dst.bottom - dst.top);   int left = (int)((ChooseArea.left - dst.left) * ratioWidth);   int right = (int)(left + (ChooseArea.right - ChooseArea.left) * ratioWidth);   int top = (int)((ChooseArea.top - dst.top) * ratioHeight);   int bottom = (int)(top + (ChooseArea.bottom - ChooseArea.top) * ratioHeight);   src = new RectF(left,top,right,bottom);   firstFlag = true;   set_LeftArea_Alpha();   return Bitmap.createBitmap(bitMap, left, top, right-left, bottom-top);  }    //取得ChooseArea对象  public RectF getChooseArea(){   return ChooseArea;  }    public void moveChooseArea(int move_x,int move_y){   if(ChooseArea.left + move_x >= dst.left && ChooseArea.right + move_x <= dst.right   && ChooseArea.top + move_y >= dst.top && ChooseArea.bottom + move_y <= dst.bottom){    ChooseArea.set(ChooseArea.left + move_x,ChooseArea.top+move_y      ,ChooseArea.right + move_x,ChooseArea.bottom+move_y);   }else{    if(ChooseArea.left + move_x < dst.left){     ChooseArea.set(dst.left,ChooseArea.top       ,ChooseArea.right+dst.left-ChooseArea.left,ChooseArea.bottom);    }    if(ChooseArea.right + move_x > dst.right){     ChooseArea.set(ChooseArea.left+dst.right-ChooseArea.right,ChooseArea.top       ,dst.right,ChooseArea.bottom);    }        if(ChooseArea.top + move_y < dst.top){     ChooseArea.set(ChooseArea.left,dst.top       ,ChooseArea.right,ChooseArea.bottom+dst.top-ChooseArea.top);    }        if(ChooseArea.bottom + move_y > dst.bottom){     ChooseArea.set(ChooseArea.left,ChooseArea.top+dst.bottom-ChooseArea.bottom       ,ChooseArea.right,dst.bottom);    }   }   this.setPressRecLoc();   mPaint.setColor(Color.GREEN);   this.invalidate();  }    public boolean onTouchEvent(MotionEvent event){   mPaint.setColor(Color.RED);            if(event.getAction() == MotionEvent.ACTION_DOWN && cutFlag){       //System.out.println(event.getX() + "," + event.getY());              mx = (int)event.getX();    my = (int)event.getY();       if(this.judgeLocation(mx,my)){        touchFlag = true;        mPaint.setColor(Color.GREEN);        this.invalidate();        return true;       }else{               if(this.findPresseddst((int)event.getX(), (int)event.getY())){         touchFlag = true;         mPaint.setColor(Color.RED);         return true;        }       }      }            if(event.getAction() == MotionEvent.ACTION_MOVE && touchFlag){       //判断是否点击了哪个个小矩形框       if(this.isOutOfArea((int)event.getX(), (int)event.getY())){        return true;       }              //如果选择区域大小跟图像大小一样时，就不能移动       if(ChooseArea.left == dst.left && ChooseArea.top == dst.top &&          ChooseArea.right == dst.right && ChooseArea.bottom == dst.bottom){       }else{        this.moveChooseArea((int)event.getX() - mx, (int)event.getY() - my);        mx = (int)event.getX();        my = (int)event.getY();       }      }                  if(event.getAction() == MotionEvent.ACTION_UP){       recFlag = -1;       this.invalidate();       touchFlag = false;      }            return super.onTouchEvent(event);     }          private boolean isOutOfArea(int x,int y){   switch(recFlag){   case Crop_Canvas.PRESS_LB:    this.pressLB(x - mx, y - my);    break;   case Crop_Canvas.PRESS_LT:    this.pressLT(x - mx, y - my);    break;   case Crop_Canvas.PRESS_RB:    this.pressRB(x - mx, y - my);    break;   case Crop_Canvas.PRESS_RT:    this.pressRT(x - mx, y - my);    break;   default:return false;   }   mx = x;   my = y;   this.invalidate();   return true;  }    public boolean findPresseddst(int x,int y){   boolean returnFlag = false;   if(this.isInRect(x, y, recLB)){    recFlag = Crop_Canvas.PRESS_LB;    returnFlag = true;   }else if(this.isInRect(x, y, recLT)){    recFlag = Crop_Canvas.PRESS_LT;    returnFlag = true;   }else if(this.isInRect(x, y, recRB)){    recFlag = Crop_Canvas.PRESS_RB;    returnFlag = true;   }else if(this.isInRect(x, y, recRT)){    recFlag = Crop_Canvas.PRESS_RT;    returnFlag = true;   }      return returnFlag;  }    public boolean isInRect(int x,int y,RectF rect){   if(x >= rect.left -20 && x <= rect.right + 20 && y > rect.top - 20 && y < rect.bottom + 20){    return true;   }   return false;  }    private void pressLB(int x,int y){   float left = ChooseArea.left + x;   float right = ChooseArea.right;   float top = ChooseArea.top;   float bottom = ChooseArea.bottom + y;   if(left <= right - 30 && left >= dst.left && bottom <= dst.bottom && bottom >= top + 30){     ChooseArea.set(left,top,right,bottom);   }else{    if(left + x < dst.left){     left = dst.left;    }        if(bottom + y > dst.bottom){     bottom = dst.bottom;    }        if(ChooseArea.left + x > ChooseArea.right - 30){     left = ChooseArea.right - 30;    }        if(ChooseArea.bottom + y < ChooseArea.top + 30){     bottom = ChooseArea.top + 30;    }    ChooseArea.set(left,top,right,bottom);   }   this.setPressRecLoc();  }      private void pressLT(int x,int y){   float left = ChooseArea.left + x;   float right = ChooseArea.right;   float top = ChooseArea.top + y;   float bottom = ChooseArea.bottom;   if(left <= right - 30 && left >= dst.left && top <= bottom - 30 && top >= dst.top){    ChooseArea.set(left,top,right,bottom);   }else{    if(left < dst.left){     left = dst.left;    }        if(top < dst.top){     top = dst.top;    }        if(left > right - 30){     left = right - 30;    }        if(top > bottom - 30){     top = bottom - 30;    }    ChooseArea.set(left,top,right,bottom);   }   this.setPressRecLoc();  }      private void pressRT(int x,int y){   float left = ChooseArea.left;   float right = ChooseArea.right + x;   float top = ChooseArea.top + y;   float bottom = ChooseArea.bottom;      if(right <= dst.right && right >= left + 30 && top <= bottom - 30 && top >= dst.top){    ChooseArea.set(left,top,right,bottom);   }else{    if(right > dst.right){     right = dst.right;    }        if(top < dst.top){     top = dst.top;    }        if(right < left + 30){     right = left + 30;    }        if(top > bottom - 30){     top = bottom - 30;    }    ChooseArea.set(left,top,right,bottom);   }   this.setPressRecLoc();  }      private void pressRB(int x,int y){   float left = ChooseArea.left;   float right = ChooseArea.right + x;   float top = ChooseArea.top;   float bottom = ChooseArea.bottom + y;      if(right<= dst.right && right >= left + 30 && bottom <= dst.bottom && bottom >= top + 30){    ChooseArea.set(left,top,right,bottom);   }else{    if(right > dst.right){     right = dst.right;    }        if(bottom > dst.bottom){     bottom = dst.bottom;    }        if(right < left + 30){     right = left + 30;    }        if(bottom < top + 30){     bottom = top + 30;    }    ChooseArea.set(left,top,right,bottom);   }   this.setPressRecLoc();  }    //每次转变选择区域矩形的大小或者移动，各角落上的小矩形也要转变它的Location  private void setPressRecLoc(){   recLT.set(ChooseArea.left-5,ChooseArea.top-5 , ChooseArea.left+5, ChooseArea.top+5);   recLB.set(ChooseArea.left-5,ChooseArea.bottom-5 , ChooseArea.left+5, ChooseArea.bottom+5);   recRT.set(ChooseArea.right-5,ChooseArea.top-5 , ChooseArea.right+5, ChooseArea.top+5);   recRB.set(ChooseArea.right-5,ChooseArea.bottom-5 , ChooseArea.right+5, ChooseArea.bottom+5);  }     public boolean judgeLocation(float x,float y){      float start_x = this.getChooseArea().left;      float start_y = this.getChooseArea().top;      float last_x = this.getChooseArea().right;      float last_y = this.getChooseArea().bottom;      //System.out.println("chubi:" + x + "," + y);      //System.out.println(start_y + "," + last_y);      if(x > start_x+10 && x < last_x-10 && y > start_y+10 && y < last_y-10){       return true;      }      return false;     }    public void onDraw(Canvas canvas){   super.onDraw(canvas);   if(firstFlag){    this.imageScale();    firstFlag = false;    mPaint.setColor(Color.RED);    System.out.println("Width: " + (dst.right - dst.left));    System.out.println("Height: " + (dst.bottom - dst.top));    System.out.println("Width: " + this.getDrawable().getIntrinsicWidth());    System.out.println("Height: " + this.getDrawable().getIntrinsicHeight());   }else{    set_LeftArea_Alpha();   }   canvas.drawRect(ChooseArea, mPaint);   mPaint.setColor(Color.BLUE);   canvas.drawRect(recLT, mPaint);   canvas.drawRect(recLB, mPaint);   canvas.drawRect(recRT, mPaint);      canvas.drawRect(recRB, mPaint);      canvas.drawRect(leftRectL, leftAreaPaint);   canvas.drawRect(leftRectR, leftAreaPaint);   canvas.drawRect(leftRectT, leftAreaPaint);   canvas.drawRect(leftRectB, leftAreaPaint);     }    public void set_LeftArea_Alpha(){   leftRectL.set(dst.left, dst.top, ChooseArea.left, dst.bottom);   leftRectR.set(ChooseArea.right,dst.top,dst.right,dst.bottom);   leftRectT.set(ChooseArea.left, dst.top, ChooseArea.right, ChooseArea.top);   leftRectB.set(ChooseArea.left,ChooseArea.bottom,ChooseArea.right,dst.bottom);  }  }

接下来直接看看Activity源码：

package com.artifex.mupdf.cut;   import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.util.ArrayList;  import android.app.Activity; import android.graphics.Bitmap; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.view.Window; import android.widget.Button;  import com.andorid.shu.love.R; import com.artifex.mupdf.Crop_Canvas; import com.artifex.mupdf.MuPDFActivity;  public class CutActivity extends Activity {  private Crop_Canvas canvas = null;  private Bitmap backBitmap;  private Button cancel;  private Button ensure;  private Button toPDF;   @Override  protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   requestWindowFeature(Window.FEATURE_NO_TITLE);   setContentView(R.layout.cut_image);   backBitmap = MuPDFActivity.backBitmap;   init();   cancel = (Button) findViewById(R.id.cutCancel);   cancel.setOnClickListener(new OnClickListener() {     @Override    public void onClick(View v) {     CutActivity.this.finish();    }   });   ensure = (Button) findViewById(R.id.cutEnsure);   ensure.setOnClickListener(new OnClickListener() {    @Override    public void onClick(View v) {     //图片保存的路径，之后将之转换为PDF，并以附件的形似发送邮件     File tmp = new File("/sdcard/lovereader/pic");     tmp.mkdirs();     File f = new File("/sdcard/lovereader/pic/" + "testpic" + ".png");           try {      f.createNewFile();     } catch (IOException e1) {      // TODO Auto-generated catch block      e1.printStackTrace();     }           FileOutputStream fOut = null;           try {                   fOut = new FileOutputStream(f);           } catch (FileNotFoundException e) {                   e.printStackTrace();           }           canvas.getSubsetBitmap().compress(Bitmap.CompressFormat.PNG, 100, fOut);           try {                   fOut.flush();           } catch (IOException e) {                   e.printStackTrace();           }           try {                   fOut.close();           } catch (IOException e) {                   e.printStackTrace();           }    }   });      toPDF = (Button)findViewById(R.id.toPDF);   toPDF.setOnClickListener(new OnClickListener() {        @Override    public void onClick(View v) {     // TODO Auto-generated method stub     ArrayList<String> imageUrllist = new ArrayList<String>();     imageUrllist.add("/sdcard/lovereader/pic/" + "testpic" + ".png");     String pdfUrl = "/sdcard/lovereader/tmp/Foreverlove.pdf";     File tmp = new File("/sdcard/lovereader/tmp");     tmp.mkdirs();     File file = PdfManager.Pdf(imageUrllist, pdfUrl);     try {      file.createNewFile();     } catch (IOException e) {      // TODO Auto-generated catch block      e.printStackTrace();     }         }   });  }   private void init() {   canvas = (Crop_Canvas) findViewById(R.id.myCanvas);   Bitmap bitmap = backBitmap;   canvas.setBitmap(bitmap);  }  }

ok，不依托系统的简略裁剪功能就实现了，这里笔者就不给出源代码下载了，

上述代码读者只要自己改改就能够用了。

文章结束给大家分享下程序员的一些笑话语录：一个合格的程序员是不会写出诸如 “摧毁地球” 这样的程序的，他们会写一个函数叫 “摧毁行星”而把地球当一个参数传进去。

本文章为转载内容，我们尊重原作者对文章享有的著作权。如有内容错误或侵权问题，欢迎原作者联系我们进行内容更正或删除文章。