java - 我想提取我点击的图像像素的 rgb 值，但每当我点击它时。即使所有语法都正确，它也会崩溃

Question

package com.example.camdetect;  

import androidx.appcompat.app.AppCompatActivity;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import android.graphics.Bitmap;

import com.skydoves.colorpickerview.ColorEnvelope;
import com.skydoves.colorpickerview.ColorPickerView;
import com.skydoves.colorpickerview.listeners.ColorListener;


public class MainActivity extends AppCompatActivity {

    public int[] s = new int [4];
    private static final int REQUEST_IMAGE_CAPTURE = 1;
    private ImageView imageview;
    private TextView i_b,i_g,i_r,p_r,p_g,p_b;//**these are declared globally to avoid declaring it final**

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

         i_b = this.findViewById(R.id.i_b);
         i_g = this.findViewById(R.id.i_g);
         i_r = this.findViewById(R.id.i_r);
         p_r = this.findViewById(R.id.p_r);
         p_g = this.findViewById(R.id.p_g);
         p_b = this.findViewById(R.id.p_b);

        ColorPickerView colorPickerView = findViewById(R.id.colorPickerView);
        imageview = this.findViewById(R.id.imageview);

托盘选择颜色

        colorPickerView.setColorListener(new ColorListener() {
            @Override
            public void onColorSelected(int color, boolean fromUser) {

                ColorEnvelope colorenvelope = new ColorEnvelope(color);
                int c[] = colorenvelope.getArgb();
                p_r.setText(String.valueOf(c[1]));
                p_g.setText(String.valueOf(c[2]));
                p_b.setText(String.valueOf(c[3]));
                for (int i = 1; i < 4; i++) {
                    s[i] = c[i];
                }

            }

        });

我现在在触摸它时获取的图像将给出该位置的 rgb 值我也尝试过 onclicklistner 但不起作用，如果我自己在代码中给出 x 和 y 0 的值，那么它工作正常所有其他部分都很好我认为问题在于获取 x 和 y 的值

        imageview.setOnTouchListener(new View.OnTouchListener(){
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                int[] viewCoords = new int[2];
                imageview.getLocationOnScreen(viewCoords);
                int x = Math.round(event.getX());
                int y = Math.round(event.getY());
                int imageX = x- viewCoords[0];
                int imageY = y - viewCoords[1];
                ImageView image = ((ImageView)v);
                Bitmap bitmap = ((BitmapDrawable)image.getDrawable()).getBitmap();
                int pixel = bitmap.getPixel(imageX,imageY);
                int r,g,b;
                r = Color.red(pixel);
                g = Color.green(pixel);
                b = Color.blue(pixel);
                i_r.setText(String.valueOf(r));
                i_g.setText(String.valueOf(g));
                i_b.setText(String.valueOf(b));
                if(s[1] == r && s[2] == g && s[3] == b){
                    Toast.makeText(getApplicationContext(),"Match Found",Toast.LENGTH_SHORT).show();}
                else{
                    Toast.makeText(getApplicationContext(),"Match Not Found",Toast.LENGTH_SHORT).show();}
                return true;
            }
        });

按钮打开相机

        Button opencam = this.findViewById(R.id.opencam);
        opencam.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent takePictureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
                if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
                    startActivityForResult(takePictureIntent,REQUEST_IMAGE_CAPTURE);
                }
            }
        });

    }

从相机中获取图像

    @Override
    protected void onActivityResult(int requestCode, int resultCode,Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(requestCode == REQUEST_IMAGE_CAPTURE && resultCode == Activity.RESULT_OK)
        {
            Bundle extras = data.getExtras();
            Bitmap imageBitmap = (Bitmap)extras.get("data");
            imageview.setImageBitmap(imageBitmap);
        }
    }
}

标签： javaandroidontouchlistener