Android 自定义监听回调Listener

自定义监听回调Listener

使用场景：在某一页面布局中，除了原生View还有自定义View，当触发自定义View的击事件时，该页面的原生布局需要同步进行处理

 

demo:主页面有两部分UI，一部分是原生的UI绘制的简易糖葫芦，另一部分是自定义View绘制的圆，当点击该圆时，随机产生1-3的随机数，圆对应的色块高亮，且原生布局对应的糖葫芦消失。

结果：

下图：点击自定义圆时，随机数为2，紫色高亮，糖葫芦中紫色消失

同理，若随机数为1：

若随机数为3：

------------------------------------------分割线--------------------------------------------

思路：

【1】抽象出方法

【2】前者调用实例化对象

【3】在需要的地方调用listener

【4】前者方法实现

------------------------------------------分割线--------------------------------------------

源码：

UI：

Activity：

package com.tzbc.databindtest;//此处应为自己项目的包

import android.os.Bundle;
import android.util.Log;
import android.view.View;

import androidx.appcompat.app.AppCompatActivity;
import androidx.databinding.DataBindingUtil;

import com.tzbc.databindtest.Listener.RoundListener;
import com.tzbc.databindtest.databinding.ActivityMainBinding;


public class MainActivity extends AppCompatActivity implements RoundListener {
    private static final String TAG = "tzbc";
    private static final int PINK = 1;
    private static final int PURPLE = 2;
    private static final int ORANGE = 3;

    private TestVM vm;
    private ActivityMainBinding activityMainBinding;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        activityMainBinding = DataBindingUtil.setContentView(this, R.layout.activity_main);
        vm = new TestVM();
        activityMainBinding.setVm(vm);

        activityMainBinding.rvRound.resetDrawHigh();
        activityMainBinding.rvRound.setRoundListener(this);
    }

    @Override
    public void eatRound(int eatIndex) {
        Log.e(TAG, "即将吃掉糖葫芦...");
        switch (eatIndex){
            case PINK:
                activityMainBinding.ivRoundPink.setVisibility(View.INVISIBLE);
                break;
            case PURPLE:
                activityMainBinding.ivRoundPurple.setVisibility(View.INVISIBLE);
                break;
            case ORANGE:
                activityMainBinding.ivRoundOrange.setVisibility(View.INVISIBLE);
                break;
        }
        Log.e(TAG, "已经吃掉糖葫芦!");
    }

    @Override
    public void resetRound() {
        Log.e(TAG, "正在重置糖葫芦...");
        resetRoundVisibility();
    }

    private void resetRoundVisibility(){
        activityMainBinding.ivRoundPink.setVisibility(View.VISIBLE);
        activityMainBinding.ivRoundPurple.setVisibility(View.VISIBLE);
        activityMainBinding.ivRoundOrange.setVisibility(View.VISIBLE);
    }
}

自定义View：

package com.tzbc.databindtest;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;

import com.tzbc.databindtest.Listener.RoundListener;

import java.util.Random;

/**
 * Created by 桃子不出 on 2020/4/15.
 *
 * @author tzbc
 */
public class RoundView extends View {
    private static final String TAG = "RoundView";

    private RoundListener roundListener;

    private int width, height;
    private Paint paintPink, paintPurple, paintOrange;
    private Paint paintPinkHigh, paintPurpleHigh, paintOrangeHigh;

    private boolean drawHighPink = false;
    private boolean drawHighOrange = false;
    private boolean drawHighPurple = false;

    public RoundView(Context context) {
        super(context);
        init();
    }

    public RoundView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    private void init() {
        paintPink = new Paint();
        paintPink.setColor(Color.parseColor("#DF7D9E"));
        paintPink.setStyle(Paint.Style.FILL);
        paintPink.setAntiAlias(true);

        paintPurple = new Paint();
        paintPurple.setColor(Color.parseColor("#D05AE6"));
        paintPurple.setStyle(Paint.Style.FILL);
        paintPurple.setAntiAlias(true);

        paintOrange = new Paint();
        paintOrange.setColor(Color.parseColor("#E97A70"));
        paintOrange.setStyle(Paint.Style.FILL);
        paintOrange.setAntiAlias(true);

        //用于高亮部分
        paintPinkHigh = new Paint();
        paintPinkHigh.setColor(Color.parseColor("#F33D7A"));
        paintPinkHigh.setStyle(Paint.Style.FILL);
        paintPinkHigh.setAntiAlias(true);

        paintPurpleHigh = new Paint();
        paintPurpleHigh.setColor(Color.parseColor("#A216BD"));
        paintPurpleHigh.setStyle(Paint.Style.FILL);
        paintPurpleHigh.setAntiAlias(true);

        paintOrangeHigh = new Paint();
        paintOrangeHigh.setColor(Color.parseColor("#F04D3E"));
        paintOrangeHigh.setStyle(Paint.Style.FILL);
        paintOrangeHigh.setAntiAlias(true);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        width = getMeasuredWidth();
        height = getMeasuredHeight();
    }

    @SuppressLint("NewApi")
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        canvas.drawArc(0, 0, width, height, 270, 120, true, paintPink);
        canvas.drawArc(0, 0, width, height, 30, 120, true, paintPurple);
        canvas.drawArc(0, 0, width, height, 150, 120, true, paintOrange);

        if (drawHighPink) {
            canvas.drawArc(0, 0, width, height, 270, 120, true, paintPinkHigh);
        } else if (drawHighPurple) {
            canvas.drawArc(0, 0, width, height, 30, 120, true, paintPurpleHigh);
        } else if (drawHighOrange) {
            canvas.drawArc(0, 0, width, height, 150, 120, true, paintOrangeHigh);
        }
    }

    public void setRoundListener(RoundListener listener) {
        this.roundListener = listener;
    }

    public void resetDrawHigh() {
        drawHighPink = false;
        drawHighPurple = false;
        drawHighOrange = false;
        if (roundListener != null) {
            roundListener.resetRound();
        }
    }

    private int getRandom() {
        Random random = new Random();
        return random.nextInt(3) % (3 - 1 + 1) + 1;
    }

    private void updateRandom(int index) {
        resetDrawHigh();
        switch (index) {
            case 1:
                drawHighPink = true;
                break;
            case 2:
                drawHighPurple = true;
                break;
            case 3:
                drawHighOrange = true;
                break;
        }
        invalidate();
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        int randomIndex = getRandom();
        Log.e(TAG, "被选中的糖葫芦为 : " + randomIndex);
        updateRandom(randomIndex);
        if (roundListener != null) {
            roundListener.eatRound(randomIndex);
        }
        return super.onTouchEvent(event);
    }
}

Listener:

package com.tzbc.databindtest.Listener;

/**
 * Created by 桃子不出 on 2020/4/15.
 *
 * @author tzbc
 */
public interface RoundListener {
    /**
     * 吃掉的第几颗糖葫芦
     *
     * @param eatIndex eatIndex
     */
    void eatRound(int eatIndex);

    /**
     * 重置糖葫芦
     */
    void resetRound();
}