Android开发：Bitmap和canvas的应用

文章由LinuxBoy分享于2019-04-01 03:04:37热评（56）

Android开发：Bitmap和canvas的应用

画虚线<div>SET_WALLPAPER </div>

public class Canvas extends Activity implements OnTouchListener {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);// 去掉标题栏
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);// 去掉信息栏
setContentView(R.layout.main);
iv = new ImageView(this);
bitmap = Bitmap.createBitmap(800, 480, Bitmap.Config.ARGB_8888);
iv.setImageBitmap(bitmap);
LinearLayout ll = (LinearLayout) findViewById(R.id.ll);
ll.addView(iv, new LayoutParams(800, 480));
ll.setOnTouchListener(this);
}
private android.graphics.Canvas myCanvas;
private Bitmap bitmap;
private Paint myPaint;
private ImageView iv;
private float left;
private float top;
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
myCanvas = new android.graphics.Canvas(bitmap);
myPaint = new Paint();
// myPaint.setAntiAlias(true);//抗锯齿
//
// RectF oval = new RectF(0, 0, 200, 200);
// myPaint.setColor(Color.DKGRAY);
// myCanvas.drawArc(oval, 0, 360, true, myPaint);
//
// myPaint.setColor(Color.LTGRAY);
//
// myCanvas.drawArc(oval, 0, 320, true, myPaint);
// RectF eyes = new RectF(100, 20, 130, 50);
// myPaint.setColor(Color.RED);
// myCanvas.drawArc(eyes, 0, 360, true, myPaint);
// myCanvas.drawCircle(200, 300, 100, myPaint);
System.out.println("======================");
iv.setImageBitmap(bitmap);
left = event.getX();
top = event.getY();
break;
case MotionEvent.ACTION_MOVE:
// myCanvas.drawPoint(event.getX(), event.getY(), myPaint);
// myPaint.setTypeface(Typeface.createFromFile("/sdcard/stxingka.ttf"));
// myPaint.setTextSize(50);
// myCanvas.drawText("Hello World!", event.getX(), event.getY(), myPaint);
PathEffect pathEffect = new DashPathEffect(
new float[] { 5, 5, 5, 5 }, 1);
myPaint.setColor(Color.GREEN);
myPaint.setPathEffect(pathEffect);
myPaint.setStyle(Style.STROKE);
myPaint.setStrokeWidth(3);
myCanvas.drawARGB(255, 20, 30, 41);
myCanvas.drawRect(new RectF(left, top, event.getX(), event.getY()),myPaint);
iv.setImageBitmap(bitmap);
break;
case MotionEvent.ACTION_UP:
break;
}
return true;
}

一个让Gridview项移动的例子:

public class Utils {
public static int[] image = { R.drawable.mb5u1_mb5ucom, R.drawable.mb5u2_mb5ucom,
R.drawable.mb5u3_mb5ucom, R.drawable.mb5u4_mb5ucom,
R.drawable.mb5u5_mb5ucom, R.drawable.mb5u6_mb5ucom,
R.drawable.mb5u7_mb5ucom, R.drawable.mb5u8_mb5ucom,
R.drawable.mb5u9_mb5ucom, R.drawable.mb5u10_mb5ucom,
R.drawable.mb5u11_mb5ucom, R.drawable.mb5u12_mb5ucom,
R.drawable.mb5u13_mb5ucom, R.drawable.mb5u14_mb5ucom,
R.drawable.mb5u15_mb5ucom, R.drawable.mb5u16_mb5ucom,
R.drawable.mb5u17_mb5ucom, R.drawable.mb5u18_mb5ucom,
R.drawable.mb5u19_mb5ucom, R.drawable.mb5u20_mb5ucom,
R.drawable.mb5u21_mb5ucom, R.drawable.mb5u22_mb5ucom,
R.drawable.mb5u23_mb5ucom, R.drawable.mb5u24_mb5ucom,
R.drawable.mb5u25_mb5ucom, R.drawable.mb5u26_mb5ucom,
R.drawable.mb5u27_mb5ucom, R.drawable.mb5u28_mb5ucom,
R.drawable.mb5u29_mb5ucom, R.drawable.mb5u30_mb5ucom,
R.drawable.mb5u31_mb5ucom, R.drawable.mb5u32_mb5ucom,
R.drawable.mb5u33_mb5ucom, R.drawable.mb5u34_mb5ucom,
R.drawable.mb5u35_mb5ucom, R.drawable.mb5u36_mb5ucom,
R.drawable.mb5u37_mb5ucom, R.drawable.mb5u38_mb5ucom,
R.drawable.mb5u39_mb5ucom, R.drawable.mb5u40_mb5ucom,
R.drawable.mb5u41_mb5ucom, R.drawable.mb5u42_mb5ucom,
R.drawable.mb5u43_mb5ucom, R.drawable.mb5u44_mb5ucom };
public static ArrayList<Map<String, Object>> getData() {
ArrayList<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
for (int i = 0; i < 23; i++) {
Map<String, Object> map = new HashMap<String, Object>();
map.put("img", image[i]);
list.add(map);
}
return list;
}

正式绑定

public class MyGridViewDemo extends Activity implements OnTouchListener {
private RelativeLayout myRl;
private GridView myGridView;
private ArrayList<Map<String, Object>> mArray;
private MyAdapter adapter;
private int mDragViewX;
private int mDragViewY;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);// 去掉标题栏
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);// 去掉信息栏
setContentView(R.layout.main);
myRl = (RelativeLayout) findViewById(R.id.ll);
myGridView = new GridView(this);
mArray = Utils.getData();
System.out.println(mArray.size());
adapter = new MyAdapter(this, myGridView.getId(), mArray);
myGridView.setAdapter(adapter);
// GridView的列数
myGridView.setNumColumns(5);
myRl.addView(myGridView);
myGridView.setOnTouchListener(this);
}
class MyAdapter extends ArrayAdapter<Map<String, Object>> {
public MyAdapter(Context context, int textViewResourceId,
List<Map<String, Object>> objects) {
super(context, textViewResourceId, objects);
}
public ArrayList<Map<String, Object>> getList() {
return mArray;
}
public View getView(int position, View convertView, ViewGroup parent) {
View row = convertView;
if (row == null) {
LayoutInflater inflater = getLayoutInflater();
row = (View) inflater.inflate(R.layout.mygrid_item, null);
}
ImageView imageView = (ImageView) row.findViewById(R.id.img);
imageView.setImageResource(Integer.valueOf(mArray.get(position)
.get("img").toString()));
if (from == position) {
imageView.setVisibility(View.INVISIBLE);
} else if (View.INVISIBLE == imageView.getVisibility()) {
imageView.setVisibility(View.VISIBLE);
}
Log.i("ivan", "position =" + position + "aniFrom =" + aniFrom
+ "aniTo" + aniTo);
Animation ani = null;
if (position > aniTo && position <= aniFrom) {
if (position % 5 == 0) {
ani = new TranslateAnimation(355, 0, -85, 0);
} else {
ani = new TranslateAnimation(-60, 0, 0, 0);
}
} else if (position < aniTo && position >= aniFrom) {
if (position % 5 == 4) {
ani = new TranslateAnimation(-355, 0, 85, 0);
} else {
ani = new TranslateAnimation(60, 0, 0, 0);
}
}
if (ani != null) {
ani.setAnimationListener(new AnimationListener() {
@Override
public void onAnimationStart(Animation animation) {
// TODO Auto-generated method stub
onAnimation = true;
}
@Override
public void onAnimationRepeat(Animation animation) {
// TODO Auto-generated method stub
}
@Override
public void onAnimationEnd(Animation animation) {
// TODO Auto-generated method stub
onAnimation = false;
}
});
ani.setDuration(500);
imageView.setAnimation(ani);
}
return imageView;
}
}
private boolean onAnimation = false;
private int from = -1;
private int to = -1;
private int aniTo;
private int aniFrom;
@Override
public boolean onTouch(View v, MotionEvent event) {
int x = (int) event.getX();
int y = (int) event.getY();
int position = myGridView.pointToPosition(x, y);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
// 如果没有点击到图片直接break
System.out.println("position =" + position);
if (position == -1) {
break;
}
// 获取到点击的View
View tempView = myGridView.getChildAt(position
- myGridView.getFirstVisiblePosition());
System.out.println("tempView =" + tempView);
if (tempView == null) {
break;
}
// 开启View的缓存
tempView.setDrawingCacheEnabled(true);
// tempView.getTop()获取到tempView自身的位置，因为按下的时候应该显示的位置和他自身的位置相同
// tempView.getLeft() 同理
startDragging(tempView.getDrawingCache(), tempView.getTop(),
tempView.getLeft());
// 获取点击的位置距所点击图片顶部的距离mDragViewX，mDragViewY
mDragViewX = x - tempView.getLeft();
mDragViewY = y - tempView.getTop();
from = position;
tempView.setVisibility(View.INVISIBLE);
break;
case MotionEvent.ACTION_MOVE:
if (myDragView != null) {
RelativeLayout.LayoutParams rllp = (LayoutParams) myDragView
.getLayoutParams();
rllp.leftMargin = x - mDragViewX;
rllp.topMargin = y - mDragViewY;
myDragView.setLayoutParams(rllp);
}
if (position != -1) {
to = position;
}
Log.i("ivan", "form=" + from);
if (from != to && from != -1 && to != -1 &&!onAnimation) {
aniFrom = from;
aniTo = to;
Map<String, Object> temp = adapter.getItem(from);
adapter.remove(temp);
adapter.insert(temp, to);
from = to;
}
break;
case MotionEvent.ACTION_UP:
if (myDragView != null) {
// 把myDragView 从RelativeLayout中删除
myRl.removeView(myDragView);
}
// 获取到松手位置的图片让其显示
View end = myGridView.getChildAt(from
- myGridView.getFirstVisiblePosition());
if (end != null) {
end.setVisibility(View.VISIBLE);
}
from = -1;
to = -1;
break;
}
return true;
}
private ImageView myDragView;
private void startDragging(Bitmap tempBitmap, int top, int left) {
ImageView iv = new ImageView(getApplication());
RelativeLayout.LayoutParams rllp = new RelativeLayout.LayoutParams(-2,
-2);
rllp.leftMargin = left;
rllp.topMargin = top;
iv.setImageBitmap(tempBitmap);
// 测试方法看iv是否有值作用是让此View填充全屏
// setContentView(iv);
myDragView = iv;
myRl.addView(myDragView, rllp);
// 两种写法一样
// mDragView.setLayoutParams(rllp);
// rl.addView(mDragView);
}

---------------------------------------------

dragwindow 图片拖动

public class DragwindowActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.main);
//设置窗体的属性
WindowManager.LayoutParams params = new LayoutParams();
params.height = WindowManager.LayoutParams.FILL_PARENT;
params.width = WindowManager.LayoutParams.FILL_PARENT;
params.format = PixelFormat.TRANSLUCENT;
DisplayMetrics dm = getResources().getDisplayMetrics();
final int screenWidth = dm.widthPixels;
final int screenHeight = dm.heightPixels-50; //拖动窗体内的范围
//把要拖动view布局文件孵化成view
LayoutInflater inflater = LayoutInflater.from(this);
View view = inflater.inflate(R.layout.main, null);
ImageButton button = (ImageButton) view.findViewById(R.id.ib_tt);
button.setOnTouchListener(new OnTouchListener() {
int lastX,lastY; //焦点
@Override
public boolean onTouch(View v, MotionEvent event) {
int me = event.getAction();
Log.i("TAG", "Touch:"+me); //按下是0,拖动是2,弹起是1;
switch(me){
case MotionEvent.ACTION_DOWN:
lastX = (int) event.getRawX();
lastY = (int) event.getRawY();
Log.i("TAG", "down x="+lastX+" ,y="+lastY);
break;
case MotionEvent.ACTION_MOVE:
int dx = (int) event.getRawX()-lastX;
int dy = (int) event.getRawY()-lastY;
Log.i("TAG", "d x="+dx+" ,d y="+dy); //拖动的坐标
//拖动移位后的坐标
int left = v.getLeft() + dx;
int top = v.getTop() + dy;
int right = v.getRight() + dx;
int bottom = v.getBottom() + dy;
if(left<0){
left = 0;
right=left+v.getWidth();
}
if(right>screenWidth){
right=screenWidth;
left = right-v.getWidth();
}
if(top<0){
top=0;
bottom = top+v.getHeight();
}
if(bottom>screenHeight){
bottom = screenHeight;
top = bottom - v.getHeight();
}
v.layout(left, top, right, bottom);
lastX = (int) event.getRawX();
lastY = (int) event.getRawY();
break;
case MotionEvent.ACTION_UP:
break;
}
return false;
}
});
WindowManager manager = (WindowManager) getSystemService(WINDOW_SERVICE);
manager.addView(view, params);
}

----------------------读取相册--画图保存

ImageView iv1;
Canvas canvas ;
Bitmap alteredBitmap;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
iv1 =(ImageView) findViewById(R.id.iv1);
iv1.setOnTouchListener(this);
}
public void selectImage(View view) {
Intent intent = new Intent(Intent.ACTION_PICK);
intent.setType("image/*");
startActivityForResult(intent, 200);
}
public void saveImage(View view){
try {
Uri uri = getContentResolver().insert(Media.EXTERNAL_CONTENT_URI, new ContentValues());
OutputStream os = getContentResolver().openOutputStream(uri);
Boolean result = alteredBitmap.compress(CompressFormat.JPEG, 50, os);
if(result){
Toast.makeText(this, "保存成功", 1).show();
Intent intent = new Intent(Intent.ACTION_MEDIA_MOUNTED,Uri.parse("file://"+Environment.getExternalStorageDirectory()));
sendBroadcast(intent);
}else{
Toast.makeText(this, "保存失败", 1).show();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 200) {
Uri uri = data.getData();
try {
// InputStream is =getContentResolver().openInputStream(uri);
//得到屏幕大小
Display currentDisplay = getWindowManager().getDefaultDisplay();
int dw = currentDisplay.getWidth();
int dh = currentDisplay.getHeight();
System.out.println(dw+"--"+dh);
BitmapFactory.Options bmpFactoryOptions = new BitmapFactory.Options();
// 如果设置了injustDecodeBounds这个属性,不会真的解析bitmap,只返回bitmap的宽高和图片属性
bmpFactoryOptions.inJustDecodeBounds = true;
Bitmap bmp = BitmapFactory.decodeFile("/sdcard/066.JPG",
bmpFactoryOptions); //参数传入只为得到bmp图属性，再缩小
int heightRatio = (int) Math.ceil(bmpFactoryOptions.outHeight
/ (float) dh);
int widthRatio = (int) Math.ceil(bmpFactoryOptions.outWidth
/ (float) dw);
// 判断是否要进行缩放
if (heightRatio > 1 && widthRatio > 1) {
if (heightRatio > widthRatio) {
// 高度变化大,按高度缩放
bmpFactoryOptions.inSampleSize = heightRatio;
} else {
// 宽度变化大,按宽度缩放
bmpFactoryOptions.inSampleSize = widthRatio;
}
}
// 把inJustDecodeBounds设置为false,这样才会真正的decode这个位图
bmpFactoryOptions.inJustDecodeBounds = false;
//得到新图片流
InputStream newis = getContentResolver().openInputStream(uri);
bmp = BitmapFactory.decodeStream(newis, null, bmpFactoryOptions);
// 创建一个bitmap的拷贝
// 创建了一个空的bitmap ，用原来的参数填充
alteredBitmap = Bitmap.createBitmap(bmp.getWidth(),
bmp.getHeight(), bmp.getConfig());
// 创建一个画布
canvas = new Canvas(alteredBitmap);
// 创建一个画笔
Paint paint = new Paint();
Matrix matrix = new Matrix();
canvas.drawBitmap(bmp, matrix, paint);
iv1.setImageBitmap(alteredBitmap);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
float downx = 0;
float downy = 0;
float upx = 0;
float upy = 0;
@Override
public boolean onTouch(View v, MotionEvent event) {
int eventtype = event.getAction();
Paint paint = new Paint();
paint.setColor(Color.GREEN);
paint.setStrokeWidth(5);
switch (eventtype) {
case MotionEvent.ACTION_DOWN:
downx = event.getX();
downy = event.getY();
break;
case MotionEvent.ACTION_MOVE:
upx = event.getX();
upy = event.getY();
canvas.drawLine(downx, downy, upx, upy, paint);
iv1.invalidate();
downx = upx;
downy = upy;
break;
case MotionEvent.ACTION_UP:
upx = event.getX();
upy = event.getY();
canvas.drawLine(downx, downy, upx, upy, paint);
iv1.invalidate();
break;
}
return true;
}

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