Android Bitmap.getPixels的正确理解演示源码

package com.spacesoftwares.imageeditv01; import android.content.Intent; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.ImageView; public class MainActivity extends AppCompatActivity { private ImageView mImgView; private ImageView mDstImg; private Button mBtn1, mBtn2, mBtn3, mBtn4; private Bitmap mBitmap1, mBitmap2, mBitmap3, mBitmap4, mBitmap5; int wd = 100; int ht = 100; int[] pixels; public final int BLACK = -16777216; // (0xff000000) public final int BLUE = -16776961; // (0xff0000ff) public final int CYAN = -16711681; // (0xff00ffff) public final int DKGRAY = -12303292; // (0xff444444) public final int GRAY = -7829368; // (0xff888888) public final int GREEN = -16711936; // (0xff00ff00) public final int LTGRAY = -3355444; // (0xffcccccc) public final int MAGENTA = -65281; // (0xffff00ff) public final int RED = -65536; // (0xffff0000) public final int TRANSPARENT = 0; // (0x00000000) public final int WHITE = -1; // (0xffffffff) public final int YELLOW = -256; // (0xffffff00) @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.image_view); // Load bitmap1 // options is to ensure getting the original size, i.e., no magnification or shrink when reading into memory // otherwise getWidth and getHeight will give different dimension depending on your display device BitmapFactory.Options opts = new BitmapFactory.Options(); opts.inScaled = false; opts.inPreferredConfig = Bitmap.Config.ARGB_8888; mBitmap1 = BitmapFactory.decodeResource(getResources(), R.drawable.r100, opts); wd = mBitmap1.getWidth(); ht = mBitmap1.getHeight(); mImgView = findViewById(R.id.id_image); mImgView.setScaleType(ImageView.ScaleType.CENTER); //mImgView.setImageResource(R.drawable.r100); mImgView.setImageBitmap(mBitmap1); mDstImg = findViewById(R.id.id_dst_image); //mDstImg.setScaleType(ImageView.ScaleType.CENTER); //mDstImg.setImageResource(R.drawable.r100); mDstImg.setImageBitmap(mBitmap1); mBtn1 = findViewById(R.id.id_btn1); mBtn2 = findViewById(R.id.id_btn2); mBtn3 = findViewById(R.id.id_btn3); mBtn4 = findViewById(R.id.id_btn4); setListeners(); pixels = new int[2*wd*ht]; for(int i=0; i<2*wd*ht; i++){ pixels[i] = YELLOW; } } private void setListeners(){ OnClick onClick = new OnClick(); mBtn1.setOnClickListener(onClick); mBtn2.setOnClickListener(onClick); mBtn3.setOnClickListener(onClick); mBtn4.setOnClickListener(onClick); } private class OnClick implements View.OnClickListener { int offset = 0; public void onClick(View v){ switch(v.getId()){ case R.id.id_btn1: //mDstImg.setImageDrawable(null); mBitmap1.getPixels(pixels, 0, 2*wd, 0, 0, wd, ht); mBitmap1.getPixels(pixels, wd, 2*wd, 0, 0, wd, ht); mBitmap2 = Bitmap.createBitmap(pixels, 0, 2*wd, 2*wd, ht, Bitmap.Config.ARGB_8888); mDstImg.setImageBitmap(mBitmap2); mImgView.setImageBitmap(mBitmap1); break; case R.id.id_btn2: offset = (2*wd)*(ht/2)+wd/2; mBitmap1.getPixels(pixels, offset, 2*wd-1, wd/2, ht/2, wd/2, ht/2); mBitmap3 = Bitmap.createBitmap(pixels, 0, 2*wd, 2*wd, ht, Bitmap.Config.ARGB_8888); mDstImg.setImageBitmap(mBitmap3); break; case R.id.id_btn3: mDstImg.setImageDrawable(null); offset = (2*wd)*(ht/2)+wd/2; mBitmap1.getPixels(pixels, offset, 2*wd, wd/2, ht/2, wd/2, ht/2); mBitmap1.getPixels(pixels, offset+wd, 2*wd, wd/2, ht/2, wd/2, ht/2); mBitmap4 = Bitmap.createBitmap(pixels, 0, 2*wd, 2*wd, ht, Bitmap.Config.ARGB_8888); mDstImg.setImageBitmap(mBitmap4); break; case R.id.id_btn4: mDstImg.setImageDrawable(null); offset = (2*wd)*(ht/2); mBitmap1.getPixels(pixels, offset, 2*wd, wd/2, ht/2, wd/2, ht/2); mBitmap1.getPixels(pixels, offset+wd, 2*wd, wd/2, ht/2, wd/2, ht/2); mBitmap5 = Bitmap.createBitmap(pixels, 0, 2*wd, 2*wd, ht, Bitmap.Config.ARGB_8888); mDstImg.setImageBitmap(mBitmap5); break; } } } }