本文介绍了如何绘制在不同颜色的线？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我已经开发出吸引。我想用不同颜色的线条在屏幕上线的应用程序，但所有的线都出现在相同的颜色。
我在我的code键更改颜色的颜色选择器，我想通过选择颜色每次绘制不同颜色的线，但截至目前，因为我构建线和渲染它。当我最初选择红色，画一条线，然后再选择蓝色和画一条线，现在老线也越来越变成蓝色，而不是红色的，但是我想红仍然为红色和蓝色这样任何一个可以帮助？
我的code以下
给出MyDemo.java：
公共类MyDemo扩展活动器具
ColorPickerDialog.OnColorChangedListener { 私人的LinearLayout根; 私人按钮btnReset;
私人按钮btnPickColor;
公共静态INT selectedColor = Color.BLACK;
MyImageView图。
私有静态最后弦乐COLOR_ preFERENCE_KEY =颜色; @覆盖
公共无效的onCreate（捆绑savedInstanceState）{
super.onCreate（savedInstanceState）;
的setContentView（R.layout.activity_my_demo）; 根=（的LinearLayout）findViewById（R.id.root）;
btnReset =（按钮）findViewById（R.id.reset）;
btnPickColor =（按钮）findViewById（R.id.pickColor）; 最后MyImageView视图=新MyImageView（本）;
view.setLayoutParams（新LinearLayout.LayoutParams（
LinearLayout.LayoutParams.FILL_PARENT，
LinearLayout.LayoutParams.FILL_PARENT））;
root.addView（视图）; btnReset.setOnClickListener（新View.OnClickListener（）{
公共无效的onClick（视图v）{
view.reset（）;
}
}）; btnPickColor.setOnClickListener（新View.OnClickListener（）{
公共无效的onClick（视图v）{
//颜色选择器类调用
INT颜色= preferenceManager.getDefaultShared preferences（
MyDemo.this）.getInt（COLOR_ preFERENCE_KEY，Color.WHITE）;
新ColorPickerDialog（MyDemo.this，MyDemo.this，颜色）.show（）; }
}）;
} 公共无效colorChanged（INT颜色）{
preferenceManager.getDefaultShared preferences（本）.edit（）
.putInt（COLOR_ preFERENCE_KEY，颜色）.commit（）;
selectedColor =颜色;
}
}
MyImageView.java：
公共类MyImageView扩展了ImageView的实现View.OnTouchListener { 私人INT ID = -1;
私人路径路径;
私人列表＆LT;路径和GT;路径=新的ArrayList＆LT;路径＆GT;（）;
私人列表＆LT;＆的PointF GT;点=新的ArrayList＆LT;＆的PointF GT;（）;
布尔多点触控= FALSE;
MyDemo演示; 公共MyImageView（上下文的背景下）{
超级（上下文）;
this.setOnTouchListener（本）;
Log.d（构造，控制在构造函数）;
} 公共无效复位（）{
paths.clear（）;
points.clear（）;
路径= NULL;
ID = -1;
无效（）;
} @覆盖
保护无效的onDraw（帆布油画）{
super.onDraw（画布）;
INT colorPicked = MyDemo.selectedColor;
如果（colorPicked！= Color.BLACK）{
涂料粉刷=个CreatePen（colorPicked）;
paint.setStyle（Paint.Style.STROKE）;
对于（路径路径：路径）{
canvas.drawPath（路径，油漆）;
}
的for（int i = 0; I＆LT; points.size（）;我++）{
的PointF p值= points.get（ⅰ）;
canvas.drawText（+ p.x，p.y，我，个CreatePen（colorPicked））;
}
}其他{
涂料粉刷=个CreatePen（colorPicked）;
paint.setStyle（Paint.Style.STROKE）;
对于（路径路径：路径）{
canvas.drawPath（路径，油漆）;
}}
的for（int i = 0; I＆LT; points.size（）;我++）{
的PointF p值= points.get（ⅰ）;
canvas.drawText（+ p.x，p.y，我，个CreatePen（colorPicked））;
}
}
私人的PointF复制（的PointF P）{
副本的PointF =新的PointF（）;
copy.set（P）;
返回副本;
} 公共布尔onTouch（视图V，MotionEvent事件）{
INT行动= event.getAction（）;
开关（动作＆安培; MotionEvent.ACTION_MASK）{
案例MotionEvent.ACTION_DOWN：
多点触控= FALSE; ID = event.getPointerId（0）;
的PointF P =用GetPoint（事件ID）;
路径=新路径（）;
path.moveTo（p.x，p.y）;
paths.add（路径）;
points.add（复印件（P））;
打破;
案例MotionEvent.ACTION_POINTER_DOWN：
多点触控=真;
的for（int i = 0; I＆LT; event.getPointerCount（）;我++）{
INT TID = event.getPointerId（I）
如果（TID！= ID）{
points.add（用GetPoint（事件，I））;
}
}
打破;
案例MotionEvent.ACTION_MOVE：
如果（！多点触控）{
P =用GetPoint（事件ID）;
path.lineTo（p.x，p.y）;
}
打破;
}
无效（）;
返回true;
} 私人的PointF用GetPoint（MotionEvent事件，int i）以{
INT索引= 0;
返回新的PointF（event.getX（指数），event.getY（指数））;
} 公共涂料个CreatePen（INT颜色）{
漆笔=新的油漆（）;
pen.setColor（颜色）;
浮宽度= 3;
pen.setStrokeWidth（宽）;
返回笔;
}}
ColorPickerDialog.java：
公共类ColorPickerDialog扩展对话框{ 公共接口OnColorChangedListener {
无效colorChanged（INT颜色）; } 私人最终OnColorChangedListener mListener;
私人最终诠释mInitialColor; 私有静态类ColorPickerView扩展视图{
私人最终涂料mPaint;
私人最终涂料mCenterPaint;
私人最终诠释[] mColors;
私人最终OnColorChangedListener mListener; ColorPickerView（上下文C，OnColorChangedListener L，INT颜色）{
超（C）;
mListener = 1;
mColors = INT新[] {0xFFFF0000地址，0xFFFF00FF，0xFF0000FF，
0xFF00FFFF，0xFF00FF00，0xFFFFFF00，0xFFFF0000地址};
着色器S =新SweepGradient（0，0，mColors，NULL）; mPaint =新的油漆（Paint.ANTI_ALIAS_FLAG）;
mPaint.setShader（多个）;
mPaint.setStyle（Paint.Style.STROKE）;
mPaint.setStrokeWidth（32）; mCenterPaint =新的油漆（Paint.ANTI_ALIAS_FLAG）;
mCenterPaint.setColor（颜色）;
mCenterPaint.setStrokeWidth（5）;
} 私人布尔mTrackingCenter;
私人布尔mHighlightCenter; @覆盖
保护无效的onDraw（帆布油画）{
浮动R = CENTER_X - mPaint.getStrokeWidth（）* 0.5F; canvas.translate（CENTER_X，CENTER_X）; canvas.drawOval（新RectF（-r，-r，R，R），mPaint）;
canvas.drawCircle（0，0，CENTER_RADIUS，mCenterPaint）; 如果（mTrackingCenter）{
INT C = mCenterPaint.getColor（）;
mCenterPaint.setStyle（Paint.Style.STROKE）; 如果（mHighlightCenter）{
mCenterPaint.setAlpha（0xFF的）;
}其他{
mCenterPaint.setAlpha（0x80的）;
}
canvas.drawCircle（0，0，CENTER_RADIUS
+ mCenterPaint.getStrokeWidth（），mCenterPaint）; mCenterPaint.setStyle（Paint.Style.FILL）;
mCenterPaint.setColor（C）;
}
} @覆盖
保护无效onMeasure（INT widthMeasureSpec，诠释heightMeasureSpec）{
setMeasuredDimension（CENTER_X * 2，CENTER_Y * 2）;
} 私有静态最终诠释CENTER_X = 100;
私有静态最终诠释CENTER_Y = 100;
私有静态最终诠释CENTER_RADIUS = 32; 私人诠释大道（int类型，INT D，浮动P）{
返回小号+ java.lang.Math.round（P *（D - S））;
} 私人诠释interpColor（INT颜色[]，浮动单元）{
如果（单元下; = 0）
返回颜色[0];
如果（部＆gt; = 1）
返回颜色[colors.length - 1]; 浮动P =单位*（colors.length - 1）;
INT I =（INT）P;
对 - =我; //现在p是只是小数部分[0 ... 1）和i是索引
INT C0 =颜色[I]
INT C1 =颜色第[i + 1];
诠释一个= AVE（Color.alpha（C0），Color.alpha（C1）中，p）;
INT R = AVE（Color.red（C0），Color.red（C1）中，p）;
INT G = AVE（Color.green（C0），Color.green（C1）中，p）;
INT B = AVE（Color.blue（C0），Color.blue（C1）中，p）; 返回Color.argb（A，R，G，B）;
} 私有静态最终浮动PI = 3.1415926f; @覆盖
公共布尔onTouchEvent（MotionEvent事件）{
浮X = event.getX（） - CENTER_X;
浮Y = event.getY（） - CENTER_Y;
布尔内心= java.lang.Math.sqrt（X * X + Y * Y）＆LT; = CENTER_RADIUS; 开关（event.getAction（））{
案例MotionEvent.ACTION_DOWN：
mTrackingCenter =内心;
如果（内心）{
mHighlightCenter =真;
无效（）;
打破;
}
案例MotionEvent.ACTION_MOVE：
如果（mTrackingCenter）{
如果（mHighlightCenter！=内心）{
mHighlightCenter =内心;
无效（）;
}
}其他{
浮动角=（浮点）java.lang.Math.atan2（Y，X）;
//需要打开角度[-PI ... PI]为单位[0 .... 1]
浮单位=角度/（2 * PI）;
如果（单位℃，）{
单元+ = 1;
}
mCenterPaint.setColor（interpColor（mColors，股吧））;
无效（）;
}
打破;
案例MotionEvent.ACTION_UP：
如果（mTrackingCenter）{
如果（内心）{
mListener.colorChanged（mCenterPaint.getColor（））; }
mTrackingCenter = FALSE; //所以我们得出的w / o晕
无效（）;
}
打破;
}
返回true;
}
} 公共ColorPickerDialog（上下文的背景下，OnColorChangedListener监听器，
INT initialColor）{
超级（上下文）; mListener =侦听器;
mInitialColor = initialColor;
} @覆盖
保护无效的onCreate（捆绑savedInstanceState）{
super.onCreate（savedInstanceState）;
OnColorChangedListener L =新OnColorChangedListener（）{
公共无效colorChanged（INT颜色）{
mListener.colorChanged（颜色）;
解雇（）;
}
}; 的LinearLayout布局=新的LinearLayout（的getContext（））;
layout.setOrientation（LinearLayout.VERTICAL）;
layout.setGravity（Gravity.CENTER）;
layout.setPadding（10，10，10，10）;
layout.addView（新ColorPickerView（的getContext（），L，mInitialColor）
新LinearLayout.LayoutParams（
LinearLayout.LayoutParams.WRAP_CONTENT，
LinearLayout.LayoutParams.WRAP_CONTENT））;
的setContentView（布局）;
的setTitle（选择颜色）;
}
}
解决方案
试试这个，它会帮助你。
@覆盖
保护无效的onDraw（帆布油画）{ canvas.drawBitmap（mBitmap，0，0，mBitmapPaint）;
INT colorPicked = MainActivity.selectedColor; paint1 =个CreatePen（colorPicked）;
对于（路径P：路径）{
canvas.drawPath（对，paint1）;
paint1.setColor（colorPicked）;
}}民营涂料个CreatePen（INT颜色）{
// TODO自动生成方法存根 paint1 =新的油漆（）;
paint1.setAntiAlias（真）;
paint1.setDither（真）;
paint1.setStyle（Paint.Style.STROKE）;
paint1.setStrokeJoin（Paint.Join.ROUND）;
paint1.setStrokeCap（Paint.Cap.ROUND）;
paint1.setStrokeWidth（3）;
返回paint1;
}
I have developed an application which draws lines on the screen .I want to use different colors for the lines but all the lines are appearing in same color.
I have a color picker in my code to change the colors and i want to draw lines of different colors each time by selecting colors, but as of now since i am constructing lines and rendering it.When i choose initially red and draw a line, and then later select blue and draw a line , now the older line is also getting changed to blue instead of red, However i want the red to remain as red, and blue as such can any one help?
My code is given below
MyDemo.java:
public class MyDemo extends Activity implements
ColorPickerDialog.OnColorChangedListener {
private LinearLayout root;
private Button btnReset;
private Button btnPickColor;
public static int selectedColor = Color.BLACK;
MyImageView view;
private static final String COLOR_PREFERENCE_KEY = "color";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my_demo);
root = (LinearLayout) findViewById(R.id.root);
btnReset = (Button) findViewById(R.id.reset);
btnPickColor = (Button) findViewById(R.id.pickColor);
final MyImageView view = new MyImageView(this);
view.setLayoutParams(new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT,
LinearLayout.LayoutParams.FILL_PARENT));
root.addView(view);
btnReset.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
view.reset();
}
});
btnPickColor.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// color picker class call
int color = PreferenceManager.getDefaultSharedPreferences(
MyDemo.this).getInt(COLOR_PREFERENCE_KEY, Color.WHITE);
new ColorPickerDialog(MyDemo.this, MyDemo.this, color).show();
}
});
}
public void colorChanged(int color) {
PreferenceManager.getDefaultSharedPreferences(this).edit()
.putInt(COLOR_PREFERENCE_KEY, color).commit();
selectedColor = color;
}
}
MyImageView.java:
public class MyImageView extends ImageView implements View.OnTouchListener {
private int id = -1;
private Path path;
private List<Path> paths = new ArrayList<Path>();
private List<PointF> points = new ArrayList<PointF>();
boolean multiTouch = false;
MyDemo demo;
public MyImageView(Context context) {
super(context);
this.setOnTouchListener(this);
Log.d("Constructor", " Control in constructor");
}
public void reset() {
paths.clear();
points.clear();
path = null;
id = -1;
invalidate();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
int colorPicked = MyDemo.selectedColor;
if (colorPicked != Color.BLACK) {
Paint paint = createPen(colorPicked);
paint.setStyle(Paint.Style.STROKE);
for (Path path : paths) {
canvas.drawPath(path, paint);
}
for (int i = 0; i < points.size(); i++) {
PointF p = points.get(i);
canvas.drawText("" + p.x, p.y, i, createPen(colorPicked));
}
} else {
Paint paint = createPen(colorPicked);
paint.setStyle(Paint.Style.STROKE);
for (Path path : paths) {
canvas.drawPath(path, paint);
}}
for (int i = 0; i < points.size(); i++) {
PointF p = points.get(i);
canvas.drawText("" + p.x, p.y, i, createPen(colorPicked));
}
}
private PointF copy(PointF p) {
PointF copy = new PointF();
copy.set(p);
return copy;
}
public boolean onTouch(View v, MotionEvent event) {
int action = event.getAction();
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
multiTouch = false;
id = event.getPointerId(0);
PointF p = getPoint(event, id);
path = new Path();
path.moveTo(p.x, p.y);
paths.add(path);
points.add(copy(p));
break;
case MotionEvent.ACTION_POINTER_DOWN:
multiTouch = true;
for (int i = 0; i < event.getPointerCount(); i++) {
int tId = event.getPointerId(i);
if (tId != id) {
points.add(getPoint(event, i));
}
}
break;
case MotionEvent.ACTION_MOVE:
if (!multiTouch) {
p = getPoint(event, id);
path.lineTo(p.x, p.y);
}
break;
}
invalidate();
return true;
}
private PointF getPoint(MotionEvent event, int i) {
int index = 0;
return new PointF(event.getX(index), event.getY(index));
}
public Paint createPen(int color) {
Paint pen = new Paint();
pen.setColor(color);
float width = 3;
pen.setStrokeWidth(width);
return pen;
}
}
ColorPickerDialog.java:
public class ColorPickerDialog extends Dialog {
public interface OnColorChangedListener {
void colorChanged(int color);
}
private final OnColorChangedListener mListener;
private final int mInitialColor;
private static class ColorPickerView extends View {
private final Paint mPaint;
private final Paint mCenterPaint;
private final int[] mColors;
private final OnColorChangedListener mListener;
ColorPickerView(Context c, OnColorChangedListener l, int color) {
super(c);
mListener = l;
mColors = new int[] { 0xFFFF0000, 0xFFFF00FF, 0xFF0000FF,
0xFF00FFFF, 0xFF00FF00, 0xFFFFFF00, 0xFFFF0000 };
Shader s = new SweepGradient(0, 0, mColors, null);
mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mPaint.setShader(s);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(32);
mCenterPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mCenterPaint.setColor(color);
mCenterPaint.setStrokeWidth(5);
}
private boolean mTrackingCenter;
private boolean mHighlightCenter;
@Override
protected void onDraw(Canvas canvas) {
float r = CENTER_X - mPaint.getStrokeWidth() * 0.5f;
canvas.translate(CENTER_X, CENTER_X);
canvas.drawOval(new RectF(-r, -r, r, r), mPaint);
canvas.drawCircle(0, 0, CENTER_RADIUS, mCenterPaint);
if (mTrackingCenter) {
int c = mCenterPaint.getColor();
mCenterPaint.setStyle(Paint.Style.STROKE);
if (mHighlightCenter) {
mCenterPaint.setAlpha(0xFF);
} else {
mCenterPaint.setAlpha(0x80);
}
canvas.drawCircle(0, 0, CENTER_RADIUS
+ mCenterPaint.getStrokeWidth(), mCenterPaint);
mCenterPaint.setStyle(Paint.Style.FILL);
mCenterPaint.setColor(c);
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(CENTER_X * 2, CENTER_Y * 2);
}
private static final int CENTER_X = 100;
private static final int CENTER_Y = 100;
private static final int CENTER_RADIUS = 32;
private int ave(int s, int d, float p) {
return s + java.lang.Math.round(p * (d - s));
}
private int interpColor(int colors[], float unit) {
if (unit <= 0)
return colors[0];
if (unit >= 1)
return colors[colors.length - 1];
float p = unit * (colors.length - 1);
int i = (int) p;
p -= i;
// now p is just the fractional part [0...1) and i is the index
int c0 = colors[i];
int c1 = colors[i + 1];
int a = ave(Color.alpha(c0), Color.alpha(c1), p);
int r = ave(Color.red(c0), Color.red(c1), p);
int g = ave(Color.green(c0), Color.green(c1), p);
int b = ave(Color.blue(c0), Color.blue(c1), p);
return Color.argb(a, r, g, b);
}
private static final float PI = 3.1415926f;
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX() - CENTER_X;
float y = event.getY() - CENTER_Y;
boolean inCenter = java.lang.Math.sqrt(x * x + y * y) <= CENTER_RADIUS;
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mTrackingCenter = inCenter;
if (inCenter) {
mHighlightCenter = true;
invalidate();
break;
}
case MotionEvent.ACTION_MOVE:
if (mTrackingCenter) {
if (mHighlightCenter != inCenter) {
mHighlightCenter = inCenter;
invalidate();
}
} else {
float angle = (float) java.lang.Math.atan2(y, x);
// need to turn angle [-PI ... PI] into unit [0....1]
float unit = angle / (2 * PI);
if (unit < 0) {
unit += 1;
}
mCenterPaint.setColor(interpColor(mColors, unit));
invalidate();
}
break;
case MotionEvent.ACTION_UP:
if (mTrackingCenter) {
if (inCenter) {
mListener.colorChanged(mCenterPaint.getColor());
}
mTrackingCenter = false; // so we draw w/o halo
invalidate();
}
break;
}
return true;
}
}
public ColorPickerDialog(Context context, OnColorChangedListener listener,
int initialColor) {
super(context);
mListener = listener;
mInitialColor = initialColor;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
OnColorChangedListener l = new OnColorChangedListener() {
public void colorChanged(int color) {
mListener.colorChanged(color);
dismiss();
}
};
LinearLayout layout = new LinearLayout(getContext());
layout.setOrientation(LinearLayout.VERTICAL);
layout.setGravity(Gravity.CENTER);
layout.setPadding(10, 10, 10, 10);
layout.addView(new ColorPickerView(getContext(), l, mInitialColor),
new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT));
setContentView(layout);
setTitle("Pick a Color");
}
}
解决方案
try this, it will help you
@Override
protected void onDraw(Canvas canvas) {
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
int colorPicked = MainActivity.selectedColor;
paint1 = createPen(colorPicked);
for (Path p : paths){
canvas.drawPath(p, paint1);
paint1.setColor(colorPicked);
}
}
private Paint createPen(int color) {
// TODO Auto-generated method stub
paint1 = new Paint();
paint1.setAntiAlias(true);
paint1.setDither(true);
paint1.setStyle(Paint.Style.STROKE);
paint1.setStrokeJoin(Paint.Join.ROUND);
paint1.setStrokeCap(Paint.Cap.ROUND);
paint1.setStrokeWidth(3);
return paint1;
}
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