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android 實現圖片的翻轉
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Resources res = this.getContext().getResources(); img = BitmapFactory.decodeResource(res, R.drawable.aa); Matrix matrix = new Matrix(); matrix.postRotate(180); /*翻轉180度*/ int width = img.getWidth(); int height = img.getHeight(); img_a = Bitmap.createBitmap(img, 0, 0, width, height, matrix, true);
然后可以直接把img_a draw到畫布上，canvas.drawBitmap(img_a, 10, 10, p)；
Matrix 是一個處理翻轉、縮放等圖像效果的重要類，Matrix.postScale 可設置縮放比例，默認為1
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android 實現圖片的旋轉
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public class ex04_22 extends Activity{ private ImageView mImageView;private Button btn1,btn2;private TextView mTextView;private AbsoluteLayout layout1;private int ScaleTimes=1,ScaleAngle=1; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mImageView=(ImageView)findViewById(R.id.myImageView); final Bitmap bmp=BitmapFactory.decodeResource(this.getResources(),R.drawable.ex04_22_1); final int widthOrig=bmp.getWidth(); final int heightOrig=bmp.getHeight(); mImageView.setImageBitmap(bmp); btn1=(Button)findViewById(R.id.myButton1); btn1.setOnClickListener(new OnClickListener(){ public void onClick(View v){ ScaleAngle--; if(ScaleAngle<-60){ ScaleAngle=-60; } int newWidth=widthOrig*ScaleTimes; int newHeight=heightOrig*ScaleTimes; float scaleWidth=((float)newWidth)/widthOrig; float scaleHeight=((float)newHeight)/heightOrig; Matrix matrix=new Matrix(); matrix.postScale(scaleWidth, scaleHeight); matrix.setRotate(5*ScaleAngle); Bitmap resizeBitmap=Bitmap.createBitmap(bmp, 0, 0, widthOrig, heightOrig, matrix, true); BitmapDrawable myNewBitmapDrawable=new BitmapDrawable(resizeBitmap); mImageView.setImageDrawable(myNewBitmapDrawable); } }); btn2=(Button)findViewById(R.id.myButton2); btn2.setOnClickListener(new OnClickListener(){ public void onClick(View v){ ScaleAngle++; if(ScaleAngle>60){ ScaleAngle=60; } int newWidth=widthOrig*ScaleTimes; int newHeight=heightOrig*ScaleTimes; float scaleWidth=((float)newWidth)/widthOrig; float scaleHeight=((float)newHeight)/heightOrig; Matrix matrix=new Matrix(); matrix.postScale(scaleWidth, scaleHeight); matrix.setRotate(5*ScaleAngle); Bitmap resizeBitmap=Bitmap.createBitmap(bmp, 0, 0, widthOrig, heightOrig, matrix, true); BitmapDrawable myNewBitmapDrawable=new BitmapDrawable(resizeBitmap); mImageView.setImageDrawable(myNewBitmapDrawable); } }); }**********************************************************************
實現畫面淡入淡出效果可以用 ：setAlpha(alpha);
alpha從255，逐漸遞減!
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如何實現屏幕的滾動效果，這里有兩個關鍵點，一個是實現OnGestureListener，以便在觸摸事件發生的時候，被回調。包括按下，滾動等等，按照API文檔，需要分兩步來實現檢測手勢行為。
1）創建GestureDetector實例
2) 在onTouchEvent()方法中調用GestureDetector的onTouchEvent()方法。
另一個關鍵點是自己實現一個簡單的View，來繪制圖片。
代碼如下所示。由于，我們不需要使用layout定義，所以不需要提供xml文件。
直接在程序里面setContentView()即可。
package com.j2medev; import android.app.Activity;import android.content.Context;import android.content.res.Resources;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Paint;import android.os.Bundle;import android.view.GestureDetector;import android.view.MotionEvent;import android.view.View;import android.view.ViewGroup;import android.view.GestureDetector.OnGestureListener; public class HorizontalScroll extends Activity implements OnGestureListener {private static final int X_MAX = 800;private static final int Y_MAX = 600;private int scrollX = 0;private int scrollY = 0; MyView main;Bitmap bmp;Bitmap adapt;Resources res;Paint paint;GestureDetector gestureScanner; @Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState); gestureScanner = new GestureDetector(this);paint = new Paint(); res = getResources();bmp = BitmapFactory.decodeResource(res, R.drawable.arc);adapt = Bitmap.createBitmap(bmp); main = new MyView(this);setContentView(main, new ViewGroup.LayoutParams(800, 600));} @Overridepublic boolean onTouchEvent(MotionEvent me) {return gestureScanner.onTouchEvent(me);} public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {main.handleScroll(distanceX, distanceY);return true;} public boolean onDown(MotionEvent e) {return true;} public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {return true;} public void onLongPress(MotionEvent e) {} public void onShowPress(MotionEvent e) {} public boolean onSingleTapUp(MotionEvent e) {return true;} // //////////////////// /////////////////// //////////////// class MyView extends View {public MyView(Context context) { super(context);} @Overrideprotected void onDraw(Canvas canvas) { canvas.drawBitmap(adapt, -scrollX, -scrollY, paint);} public void handleScroll(float distX, float distY) { // X-Axis //////////////////////////////// if (distX > 6.0) { if (scrollX < 460) { scrollX += 15; } } else if (distX < -6.0) { if (scrollX >= 15) { scrollX -= 15; } } // ////////////////////////////////////////// // Y-AXIS ////////////////////////////////// if (distY > 6.0) { if (scrollY < 100) { scrollY += 15; } } else if (distY < -6.0) { if (scrollY >= 15) { scrollY -= 15; } } // ////////////////////////////////////////// // // if ((scrollX <= 480) && (scrollY <= 120)) { // adapt = Bitmap.createBitmap(bmp, scrollX, scrollY, 320, 480); // invalidate(); // } invalidate();}}}**********************************************************************
教你在谷歌Android平臺中處理圖片
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操作圖像像素
現在你可以對單獨的像素進行處理了。通過使用android.graphics.Bitmap API中的getPixels，可以加載像素到一個整數數組中。
在本文例子中，你將按照一定規則對每一個像素實現著色。經過這個處理后，所有的像素將被轉化為一個范圍在0到255的字節碼。
android.graphics.Bitmap API中的setPixels則用來加載這個整數數組到一個圖像中。
最后一步是通過ImageView變量mIV來更新屏幕。以下是實現這個染色過程的代碼片段。
private void TintThePicture(int deg) { int[] pix = new int[picw * pich]; mBitmap.getPixels(pix, 0, picw, 0, 0, picw, pich); int RY, GY, BY, RYY, GYY, BYY, R, G, B, Y; double angle = (3.14159d * (double)deg) / 180.0d; int S = (int)(256.0d * Math.sin(angle)); int C = (int)(256.0d * Math.cos(angle)); for (int y = 0; y < pich; y++) for (int x = 0; x < picw; x++) { int index = y * picw + x; int r = (pix[index] >> 16) & 0xff; int g = (pix[index] >> 8) & 0xff; int b = pix[index] & 0xff; RY = ( 70 * r - 59 * g - 11 * b) / 100; GY = (-30 * r + 41 * g - 11 * b) / 100; BY = (-30 * r - 59 * g + 89 * b) / 100; Y = ( 30 * r + 59 * g + 11 * b) / 100; RYY = (S * BY + C * RY) / 256; BYY = (C * BY - S * RY) / 256; GYY = (-51 * RYY - 19 * BYY) / 100; R = Y + RYY; R = (R < 0) ? 0 : ((R > 255) ? 255 : R); G = Y + GYY; G = (G < 0) ? 0 : ((G > 255) ? 255 : G); B = Y + BYY; B = (B < 0) ? 0 : ((B > 255) ? 255 : B); pix[index] = 0xff000000 | (R << 16) | (G << 8) | B; } Bitmap bm = Bitmap.createBitmap(picw, pich, false); bm.setPixels(pix, 0, picw, 0, 0, picw, pich); // Put the updated bitmap into the main view mIV.setImageBitmap(bm); mIV.invalidate(); mBitmap = bm; pix = null; }**********************************************************************
android 圖片的放大和縮小
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public class ex04_22 extends Activity{private ImageView mImageView;private Button btn1,btn2;private TextView mTextView;private AbsoluteLayout layout1;private Bitmap bmp;private int id=0;private int displayWidth,displayHeight;private float scaleWidth=1,scaleHeight=1;private final static String filename="/data/data/ex04_22.lcs/ex04_22_2.png";@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);//取得屏幕分辨率DisplayMetrics dm=new DisplayMetrics();getWindowManager().getDefaultDisplay().getMetrics(dm);displayWidth=dm.widthPixels;displayHeight=dm.heightPixels-80;bmp=BitmapFactory.decodeResource(this.getResources(),R.drawable.ex04_22_1);layout1=(AbsoluteLayout)findViewById(R.id.layout1);mImageView=(ImageView)findViewById(R.id.myImageView);btn1=(Button)findViewById(R.id.myButton1);btn1.setOnClickListener(new OnClickListener(){public void onClick(View v){small();}});btn2=(Button)findViewById(R.id.myButton2);btn2.setOnClickListener(new OnClickListener(){public void onClick(View v){big();}});}private void small(){//獲得Bitmap的高和寬int bmpWidth=bmp.getWidth();int bmpHeight=bmp.getHeight();//設置縮小比例double scale=0.8;//計算出這次要縮小的比例scaleWidth=(float)(scaleWidth*scale);scaleHeight=(float)(scaleHeight*scale);//產生resize后的Bitmap對象Matrix matrix=new Matrix();matrix.postScale(scaleWidth, scaleHeight);Bitmap resizeBmp=Bitmap.createBitmap(bmp, 0, 0, bmpWidth, bmpHeight, matrix, true);if(id==0){layout1.removeView(mImageView);}else{layout1.removeView((ImageView)findViewById(id));}id++;ImageView imageView=new ImageView(this);imageView.setId(id);imageView.setImageBitmap(resizeBmp);layout1.addView(imageView);setContentView(layout1);btn2.setEnabled(true);}private void big(){//獲得Bitmap的高和寬int bmpWidth=bmp.getWidth();int bmpHeight=bmp.getHeight();//設置縮小比例double scale=1.25;//計算出這次要縮小的比例scaleWidth=(float)(scaleWidth*scale);scaleHeight=(float)(scaleHeight*scale);//產生resize后的Bitmap對象Matrix matrix=new Matrix();matrix.postScale(scaleWidth, scaleHeight);Bitmap resizeBmp=Bitmap.createBitmap(bmp, 0, 0, bmpWidth, bmpHeight, matrix, true);if(id==0){layout1.removeView(mImageView);}else{layout1.removeView((ImageView)findViewById(id));}id++;ImageView imageView=new ImageView(this);imageView.setId(id);imageView.setImageBitmap(resizeBmp);layout1.addView(imageView);setContentView(layout1);if(scaleWidth*scale*bmpWidth>displayWidth||scaleHeight*scale*scaleHeight>displayHeight){btn2.setEnabled(false);}}}xml文件
<?xml version="1.0" encoding="utf-8"?> <AbsoluteLayoutandroid:id="@+id/layout1"android:layout_width="fill_parent"android:layout_height="fill_parent"xmlns:android="http://schemas.android.com/apk/res/android"><ImageViewandroid:id="@+id/myImageView"android:layout_width="200px" android:layout_height="150px"android:src="@drawable/ex04_22_1"android:layout_x="0px"android:layout_y="0px"></ImageView><Buttonandroid:id="@+id/myButton1" android:layout_width="90px"android:layout_height="60px"android:text="縮小"android:textSize="18sp"android:layout_x="20px"android:layout_y="372px" ></Button><Buttonandroid:id="@+id/myButton2"android:layout_width="90px"android:layout_height="60px"android:text="放大"android:textSize="18sp" android:layout_x="210px"android:layout_y="372px"></Button></AbsoluteLayout>
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android 圖片透明度處理代碼
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public static Bitmap setAlpha(Bitmap sourceImg, int number) { int[] argb = new int[sourceImg.getWidth() * sourceImg.getHeight()]; sourceImg.getPixels(argb, 0, sourceImg.getWidth(), 0, 0,sourceImg.getWidth(), sourceImg.getHeight());// 獲得圖片的ARGB值 number = number * 255 / 100; for (int i = 0; i < argb.length; i++) { argb = (number << 24) | (argb & 0x00FFFFFF);// 修改最高2位的值 } sourceImg = Bitmap.createBitmap(argb, sourceImg.getWidth(), sourceImg.getHeight(), Config.ARGB_8888); return sourceImg; }以上就是涉及到了Android圖片處理的所有內容，包括android圖片反轉、android 圖片翻轉、android 圖片旋轉、實現畫面淡入淡出效果、android 圖片的放大和縮小以及教你在谷歌Android平臺中處理圖片。
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