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我有一個視圖，從EditText延伸，允許用戶寫一個文本，然後用手指在同一視圖中繪製。保存一個畫布供將來使用
我想要的是保存該項目以備將來使用，我在考慮應用何時被銷燬，然後打開繪圖被刪除。我想要的是下次用戶打開應用程序時保存此圖形的方法。
對於我使用sharedPreferences文本保存中的文本，併爲繪製我不知道如何可以保存。
我認爲將繪圖保存爲圖像文件不是保存它的方法，但我不知道。
編輯：
我試圖保存位圖作爲JPEG再畫到畫布上。但它不起作用，最終，它顯示的顏色爲黑色，不允許我繪製。
我的代碼如下，最後寫了我創建的兩個方法，但它們不能很好地工作。他們是saveBitmap()和openBitmap()：
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import android.content.Context;
import android.graphics.*;
import android.os.Environment;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.EditText;
public class DrawEditText extends EditText {
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
private Paint mPaint;
private MaskFilter mEmboss;
private MaskFilter mBlur;
private int brush;
private Boolean drawing;
private int maxLines;
public DrawEditText(Context c) {
super(c);
//This initializes all the objects
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mBitmapPaint.setColor(Color.TRANSPARENT);
mPaint = new Paint();
mPaint.setColor(Color.BLACK);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(5);
mPaint.setAntiAlias(true);
mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 },
0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);
drawing = false;
brush = -1;
maxLines = 20;
}
public DrawEditText(Context c, AttributeSet attrs) {
super(c, attrs);
//This initializes all the objects
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mPaint = new Paint();
mPaint.setColor(Color.BLACK);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(5);
mPaint.setAntiAlias(true);
mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 },
0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);
drawing = false;
brush = -1;
maxLines = 20;
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
super.onDraw(canvas);
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPath.reset();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
//This conditional makes that if not it's drawing no points are saved and no points are drawed
if (drawing){
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
}
return true;
} else {
return super.onTouchEvent(event);
}
}
public void changePaint(int stroke, int color){
mPaint.setColor(color);
mPaint.setStrokeWidth(stroke);
}
public void clear(){
mCanvas.drawColor(0x00AAAAAA);
mCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
setText("");
}
public void changeBrush(int id){
//String[] ids={"emboss", "blur", "another"};
switch (id) {
case 0:
mPaint.setMaskFilter(mEmboss);
brush = 0;
break;
case 1:
mPaint.setMaskFilter(mBlur);
brush = 1;
break;
case 2:
mPaint.setMaskFilter(null);
brush = -1;
break;
default:
mPaint.setMaskFilter(null);
brush = -1;
break;
}
}
public int getBrush(){
//String[] ids={"emboss", "blur", "another"};
return brush;
}
public void eraser(){
mPaint.setMaskFilter(null);
mPaint.setColor(0x00AAAAAA);
}
public void setDrawing(Boolean drawing){
this.drawing = drawing;
}
public Boolean isDrawing(){
return drawing;
}
@Override
protected void onFinishInflate() {
super.onFinishInflate();
TextWatcher watcher = new TextWatcher() {
private String text;
private int beforeCursorPosition = 0;
@Override
public void onTextChanged(CharSequence s, int start, int before,
int count) {
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
text = s.toString();
beforeCursorPosition = start;
}
@Override
public void afterTextChanged(Editable s) {
/* turning off listener */
removeTextChangedListener(this);
/* handling lines limit exceed */
if (DrawEditText.this.getLineCount() > maxLines) {
DrawEditText.this.setText(text);
DrawEditText.this.setSelection(beforeCursorPosition);
}
/* turning on listener */
addTextChangedListener(this);
}
};
this.addTextChangedListener(watcher);
}
@Override
public int getMaxLines() {
return maxLines;
}
@Override
public void setMaxLines(int maxLines) {
this.maxLines = maxLines;
}
public void saveBitmap(){
mCanvas.setBitmap(mBitmap);
File sd = Environment.getExternalStorageDirectory();
File myDir = new File(sd + "/tweeet");
myDir.mkdirs();
File f = new File(myDir, ".drawing.jpeg");
try {
if (myDir.canWrite()) {
f.createNewFile();
OutputStream os = new FileOutputStream(f);
mBitmap.compress(Bitmap.CompressFormat.JPEG, 100, os);
os.close();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public void openBitmap(){
File sd = Environment.getExternalStorageDirectory();
File myDir = new File(sd + "/tweeet");
myDir.mkdirs();
File f = new File(myDir, ".drawing.jpeg");
mBitmap = BitmapFactory.decodeFile(f.getPath());
}
}
如何做到這一點？ –