我正在制作一个简单的LED色彩控制应用程序，它通过蓝牙将数据发送到arduino，然后控制LED灯条。
我正在尝试实现色轮，然后使用getPixel选择要发送到arduino的颜色。我有很多问题让位图正确绘制和工作。我正在测试使用Android Studio预览并使用我的手机（HTC U11）在硬件上进行测试。
我无法让这张图片正确绘制。这是我的画布。
package com.example.buledin.ledstripcontrolapp;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.Display;
import android.view.View;
import android.view.WindowManager;
//we must extend View for simplicity
public class DrawableCanvas extends View {
static Canvas c;
private Paint BlueEdgePaint = new Paint();
private Paint BlackEdgePaint = new Paint();
ColourPoint point;
private Bitmap colourWheelB;
Rect rect;
public DrawableCanvas(Context context) {
super(context);
init(null, null, 0);
this.setWillNotDraw(false);
}
public DrawableCanvas(Context context, AttributeSet attrs) {
super(context, attrs);
init(context, attrs, 0);
}
public DrawableCanvas(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context, attrs, 0);
}
// This is the initialisation routine.
private void init(Context context, AttributeSet attrs, int defStyle) {
BlueEdgePaint.setColor(Color.BLUE);
BlueEdgePaint.setStrokeWidth(4);
BlueEdgePaint.setStyle(Paint.Style.STROKE);
BlueEdgePaint.setAntiAlias(true);
BlackEdgePaint.setColor(Color.BLACK);
BlackEdgePaint.setStrokeWidth(2);
BlackEdgePaint.setStyle(Paint.Style.STROKE);
BlackEdgePaint.setAntiAlias(true);
// colourWheel = getResources().getDrawable(R.drawable.color_wheel_730_no_outline);
colourWheelB = BitmapFactory.decodeResource(context.getResources(), R.drawable.color_wheel_730_no_outline);
point = new ColourPoint(0, 0);
invalidate();
}
// Here is our DRAW LOOP.
@Override
public void onDraw(Canvas c) {
//draw
DrawableCanvas.c = c;
super.onDraw(c);
//draw wheel
rect = new Rect(0, 0, c.getWidth(), c.getHeight());
c.drawBitmap(colourWheelB, 0, 0, null);
//selection circle
c.drawCircle(point.getX(), point.getY(), 20, BlueEdgePaint);
c.drawCircle(c.getWidth() / 2, c.getHeight() / 2, c.getHeight() / 2, BlackEdgePaint);
}
public void updatePoint(int x, int y) {
point.setNewCoords(x, y);
invalidate();
}
public static double distanceFromCentre(double x, double y) {
double A = Math.abs(x - (c.getWidth() / 2));
double B = Math.abs(y - (c.getHeight() / 2));
double distance = Math.sqrt(A * A + B * B);
return distance;
}
public int[] getRGBfromPoint(double x, double y ) {
int pixel = colourWheelB.getPixel((int) x ,(int) y);
int Red = Color.red(pixel);
int Green = Color.green(pixel);
int Blue = Color.blue(pixel);
int[] ret = {Red, Green, Blue};
Log.v("Coords: ", ""+point.getX() + " " + point.getY());
Log.v("Color:", "Red = " + Red + " " + "Green = " + Green + "Blue = " + Blue);
return ret;
}
}
这是我的布局
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/content_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.example.buledin.ledstripcontrolapp.MainActivity"
tools:showIn="@layout/activity_main">
<SeekBar
android:id="@+id/seekBar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:layout_alignParentStart="true"
android:layout_marginBottom="22dp"
android:paddingBottom="10dp"
android:paddingLeft="30dp"
android:paddingRight="30dp"
android:paddingTop="10dp"
android:progress="100" />
<Button
android:id="@+id/strobebutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginTop="73dp"
android:text="Strobe" />
<Button
android:id="@+id/rainbowbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/strobebutton"
android:layout_centerHorizontal="true"
android:text="RAINBOW" />
<Button
android:id="@+id/offbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_alignTop="@+id/rainbowbutton"
android:text="Off" />
<TextView
android:id="@+id/status"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_alignParentTop="true"
android:text="Null" />
<TextView
android:id="@+id/textView2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_above="@+id/seekBar"
android:layout_alignParentStart="true"
android:gravity="center"
android:text="Brightness"
android:textColor="@color/colorPrimaryDark"
android:textSize="20sp" />
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_toEndOf="@+id/rainbowbutton"
android:text="Status:" />
<TextView
android:id="@+id/brightness"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:text="100" />
<com.example.buledin.ledstripcontrolapp.DrawableCanvas
android:id="@+id/canvas"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/textView2"
android:layout_below="@+id/strobebutton"
android:color="#66000000" />
</RelativeLayout>
Here is what it looks like on the phone
And here is what it looks like in the Android studio preview
请注意，对于色彩轮和“轮廓圆”，缩放都是错误的，出于美观原因我将其绘制在顶部。我不知道为什么缩放是完全错误的，但是当我在硬件测试中使用手机上的应用程序时，我基本上只能设置第一个屏幕截图中显示的颜色，所以我在3/4的轮子上输掉了。
这是真正的踢球者和真正令人头疼的问题：尽管屏幕上的图像看起来如此（我已经让它成功地在我的手机上绘制了一个完整的圆圈）我仍然只能选择颜色就像只剩下车轮的左上角1/4一样。
