这两天整理了一个自己项目中用到的获取图片颜色的效果，话不多说，先看下效果：
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效果图
如上，就是根据手指触摸的位置获取颜色值，色盘是一张图片，代码也很简单，如下：
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<FrameLayout
android:id="@+id/frame_layout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"/>
<Button
android:id="@+id/btn"
android:layout_width="match_parent"
android:layout_height="45dp"
android:text="选择的颜色"
android:layout_alignParentBottom="true"/>
</RelativeLayout>
MainActivity ：
public class MainActivity extends AppCompatActivity {
private static final String TAG = "MainActivity";
private FrameLayout frame_layout;
private Button btn;
private GetPictureColorView mGetPictureColorView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
init();
}
private void initView() {
frame_layout = (FrameLayout) findViewById(R.id.frame_layout);
btn = (Button) findViewById(R.id.btn);
}
private void init() {
mGetPictureColorView = new GetPictureColorView(MainActivity.this);
frame_layout.addView(mGetPictureColorView);
mGetPictureColorView.setOnUpdateColorListener(new
GetPictureColorView.OnUpdateColorListener() {
@Override
public void changeColor(int color) {
btn.setBackgroundColor(color);
}
});
}
GetPictureColorView：自定义view获取图片颜色
public class GetPictureColorView extends View {
private static final String TAG = "GetPictureColorView";
private Paint mPaint;
private Bitmap bigIcon, smallIcon;
private int radius;
private int size;
private int color = Color.WHITE;//颜色，默认为白色
public OnUpdateColorListener onUpdateColorListener;
private Bitmap mBackgroundBitmap;
private Paint paint;
private float nowX, nowY;
private ColorBean bean;
private int nowAction;
public interface OnUpdateColorListener {
void changeColor(int color);
}
public void setOnUpdateColorListener(OnUpdateColorListener mOnUpdateColorListener) {
this.onUpdateColorListener = mOnUpdateColorListener;
}
public GetPictureColorView(Context context) {
super(context, null);
init();
initView();
}
public GetPictureColorView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
initView();
}
private void init() {
paint = new Paint();
mPaint = new Paint();
mPaint.setAntiAlias(true);
paint.setAntiAlias(true);
}
private void initView() {
mBackgroundBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.light_group_bg);
size = Math.min(mBackgroundBitmap.getWidth(),
mBackgroundBitmap.getHeight());
radius = size / 2;
bigIcon = BitmapFactory.decodeResource(getResources(), R.drawable.positioning_big_target);
smallIcon = BitmapFactory.decodeResource(getResources(), R.drawable.positioning_target);
setData();
}
private void setData() {
bean = new ColorBean();
Integer col = Color.WHITE;
bean.x = radius;
bean.y = radius;
bean.color = col;
bean.type = true;
nowX = bean.x;
nowY = bean.y;
color = bean.color;
}
public GetPictureColorView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(size, size);
}
@Override protected void onDraw(Canvas canvas) {
//画背景色盘
canvas.drawBitmap(mBackgroundBitmap, 0, 0, mPaint);
if (bean.type && (Math.hypot(nowX - radius, nowY - radius) < (radius) * 8 / 10)) {
bean.x = (int) nowX;
bean.y = (int) nowY;
canvas.drawBitmap(bigIcon, bean.x - bigIcon.getWidth() / 2, bean.y - bigIcon.getHeight() / 2, mPaint);
} else {
canvas.drawBitmap(smallIcon, bean.x - smallIcon.getWidth() / 2, bean.y - smallIcon.getHeight() / 2, mPaint);
}
if (nowAction == MotionEvent.ACTION_UP || nowAction == MotionEvent.ACTION_CANCEL) {
if (onUpdateColorListener != null) {
onUpdateColorListener.changeColor(color);
}
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
nowX = event.getX();
nowY = event.getY();
//手指按下
if (event.getAction() == MotionEvent.ACTION_DOWN) {
if (Math.hypot(nowX - radius, nowY - radius) < (radius) * 8 / 10) {
bean.type = true;
int pixel = mBackgroundBitmap.getPixel((int) event.getX(), (int) event.getY());
color = pixel;
bean.color = pixel;
} else {
return true;
}
}
//手指滑动或者离开
else if (event.getAction() == MotionEvent.ACTION_MOVE || event.getAction() == MotionEvent.ACTION_UP) {
if ((Math.hypot(nowX - radius, nowY - radius) < (radius) * 7 / 10)) {
int pixel = mBackgroundBitmap.getPixel((int) event.getX(), (int)
event.getY());
color = pixel;
bean.color = pixel;
} else {
return true;
}
} else {
return true;
}
nowAction = event.getAction();
nowX = event.getX();
nowY = event.getY();
invalidate();
return true;
}
private class ColorBean {
boolean type = false;//是否点击
int color;
int x, y;//位置
}
}
