1. 画画板 示例代码
public class MainActivity extends Activity {
private ImageView iv;
private Bitmap baseBitmap;
private Canvas canvas;
private Paint paint;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
iv = (ImageView) findViewById(R.id.iv);
paint = new Paint();
paint.setStrokeWidth(5);
paint.setColor(Color.GREEN);
// 创建一个可以被修改的bitmap
baseBitmap = Bitmap.createBitmap(320, 359,
Bitmap.Config.ARGB_8888);
System.out.println("图宽度:"+iv.getWidth());
System.out.println("图宽高:"+iv.getHeight());
canvas = new Canvas(baseBitmap);
canvas.drawColor(Color.WHITE);
// 知道用户手指在屏幕上移动的轨迹
iv.setOnTouchListener(new OnTouchListener() {
//定义手指开始位置的坐标
int startX;
int startY;
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN: // 手指第一次接触屏幕
System.out.println("手指按下");
startX = (int) event.getX();
startY = (int) event.getY();
break;
case MotionEvent.ACTION_MOVE: // 手指在屏幕上滑动
System.out.println("手指移动");
int newX = (int) event.getX();
int newY = (int) event.getY();
canvas.drawLine(startX,startY, newX, newY, paint);
//重新更新画笔的开始位置.
startX = (int) event.getX();
startY = (int) event.getY();
iv.setImageBitmap(baseBitmap);
break;
case MotionEvent.ACTION_UP:// 手指离开屏幕
break;
}
return true;
}
});
}
public void save(View view) {
try {
File file = new File(Environment.getExternalStorageDirectory(),System.currentTimeMillis()+".jpg");
FileOutputStream stream = new FileOutputStream(file);
baseBitmap.compress(CompressFormat.JPEG, 100, stream);
stream.close();
Toast.makeText(this, "保存图片成功", 1).show();
//模拟一个消息 通知系统sd卡被重新挂载了.
Intent intent = new Intent();
intent.setAction(Intent.ACTION_MEDIA_MOUNTED);
intent.setData(Uri.fromFile(Environment.getExternalStorageDirectory()));
sendBroadcast(intent);
} catch (Exception e) {
Toast.makeText(this, "保存图片失败", 1).show();
e.printStackTrace();
}
}
}
2. 图片缩放
public class MainActivity extends Activity {
private ImageView iv_src;
private ImageView iv_dest;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
iv_src = (ImageView) findViewById(R.id.iv_src);
iv_src.setImageBitmap(BitmapFactory.decodeFile("/sdcard/tom.png"));
iv_dest = (ImageView) findViewById(R.id.iv_dest);
}
public void click(View view) {
Bitmap bitmap = BitmapFactory.decodeFile("/sdcard/tom.png");
Bitmap baseBitmap = Bitmap.createBitmap(bitmap.getWidth()*2,
bitmap.getHeight()/2, bitmap.getConfig());
Canvas canvas = new Canvas(baseBitmap);
Matrix matrix = new Matrix();
/* matrix.setValues(new float[] {
2, 0, 0,
0, 0.5f, 0,
0, 0, 1
});*/
matrix.setScale(2.0f, 0.5f);
canvas.drawBitmap(bitmap, matrix, new Paint());
iv_dest.setImageBitmap(baseBitmap);
}
}
3. 图片旋转
Matrix matrix = new Matrix(); matrix.setRotate(15); canvas.drawBitmap(bmp, matrix, paint); 消除锯齿 paint.setAntiAlias(true); 指定圆心的旋转 matrix.setRotate(15,bmp.getWidth()/2,bmp.getHeight()/2);
4. 图片平移
matrix.setTranslate(1.5f,-10);
5. 镜面效果
matrix.setScale(-1, 1);
matrix.postTranslate(bmp.getWidth(),0);
6. 倒影
matrix.setScale(1, -1);
matrix.postTranslate(0, bmp.getHeight());
7. 图片合成
public class MainActivity extends Activity {
private ImageView iv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
iv = (ImageView) findViewById(R.id.iv);
//第一张图
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.a1);
//第二张图
Bitmap addbitMap = BitmapFactory.decodeResource(getResources(), R.drawable.a3);
//可修改的位图 及 画板
Bitmap alterBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig());
Canvas canvas = new Canvas(alterBitmap);
Paint point = new Paint();
point.setColor(Color.BLACK);
point.setXfermode(new PorterDuffXfermode(android.graphics.PorterDuff.Mode.SRC_OVER));//合成模式
//将第一张图和第二张图画到画板的可修改位图上
canvas.drawBitmap(bitmap, new Matrix(), point);
canvas.drawBitmap(addbitMap, new Matrix(), point);
iv.setImageBitmap(alterBitmap);
}
}
8. 颜色处理，RGB颜色， 亮度， 饱和度
亮度处理
ColorMatrix cm = new ColorMatrix();
float contrast = 2;
cm.set(new float[] {
contrast, 0, 0, 0, 0,
0, contrast, 0, 0, 0,
0, 0, contrast, 0, 0,
0, 0, 0, 1, 0 });
paint.setColorFilter(new ColorMatrixColorFilter(cm));
RGB 及 饱和度
public class MainActivity extends Activity {
private ImageView iv1;
private SeekBar sb1;
private SeekBar sb2;
private SeekBar sb3;
private SeekBar sb4;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main2);
iv1 = (ImageView) findViewById(R.id.iv_1);
sb1 = (SeekBar) findViewById(R.id.seekBar1);
sb2 = (SeekBar) findViewById(R.id.seekBar2);
sb3 = (SeekBar) findViewById(R.id.seekBar3);
sb4 = (SeekBar) findViewById(R.id.seekBar4);
sb1.setMax(255);
sb2.setMax(255);
sb3.setMax(255);
sb4.setMax(255);
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.top);
final Bitmap baseBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig());
final Canvas canvas = new Canvas(baseBitmap);
final Matrix matrix = new Matrix();
final Paint paint = new Paint();
canvas.drawBitmap(bitmap, matrix, paint);
iv1.setImageBitmap(baseBitmap);
//调节R 红色
sb1.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromUser) {
int ret = seekBar.getProgress();
if(ret!=0)
{
ColorMatrix cm = new ColorMatrix();
cm.set(new float[]{
ret/128.0f,0,0,0,0,
0,1,0,0,0,
0,0,1,0,0,
0,0,0,1,0,
});
paint.setColorFilter(new ColorMatrixColorFilter(cm));
canvas.drawBitmap(baseBitmap, matrix, paint);
iv1.setImageBitmap(baseBitmap);
}
}
});
//调节G 绿色
sb2.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromUser) {
int ret = seekBar.getProgress();
if(ret!=0)
{
ColorMatrix cm = new ColorMatrix();
cm.set(new float[]{
1,0,0,0,0,
0,ret/128.0f,0,0,0,
0,0,1,0,0,
0,0,0,1,0,
});
paint.setColorFilter(new ColorMatrixColorFilter(cm));
canvas.drawBitmap(baseBitmap, matrix, paint);
iv1.setImageBitmap(baseBitmap);
}
}
});
//调节B 蓝色
sb3.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromUser) {
int ret = seekBar.getProgress();
if(ret!=0)
{
ColorMatrix cm = new ColorMatrix();
cm.set(new float[]{
1,0,0,0,0,
0,1,0,0,0,
0,0,ret/128.0f,0,0,
0,0,0,1,0,
});
paint.setColorFilter(new ColorMatrixColorFilter(cm));
canvas.drawBitmap(baseBitmap, matrix, paint);
iv1.setImageBitmap(baseBitmap);
}
}
});
//调节 饱和度
sb4.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromUser) {
int ret = seekBar.getProgress();
if(ret!=0)
{
ColorMatrix cm = new ColorMatrix();
cm.setSaturation(ret/128.0f);
paint.setColorFilter(new ColorMatrixColorFilter(cm));
canvas.drawBitmap(baseBitmap, matrix, paint);
iv1.setImageBitmap(baseBitmap);
}
}
});
}
}