如何检测视图之间的滑动以在android java中创建路径？

Posted 2023-02-22

【中文标题】如何检测视图之间的滑动以在android java中创建路径？

【英文标题】：How to detect swipe between views to make path across them in android java?

【发布时间】：2020-06-13 08:04:19

【问题描述】：

我正在尝试制作带有字母按钮的游戏，如果用户在它们上滑动，那么它应该检测视图并在它们之间划一条线。我搜索了许多教程、示例和问题，但无法理解。我附上了图片以帮助理解这个问题。

代码如下：

MainActivity.java

package com.example.detecttouch;

import androidx.appcompat.app.AppCompatActivity;

import android.graphics.Rect;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity 
    TextView btn1, btn2;
    TextView txtresult;
    Rect outRect = new Rect();
    int[] location = new int[2];
    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        btn1 = findViewById(R.id.btn1);
        btn2 =  findViewById(R.id.btn2);
        txtresult = (TextView) findViewById(R.id.txtresult);

        btn1.setOnClickListener(new View.OnClickListener() 
            @Override
            public void onClick(View v) 
        );

        btn1.setOnTouchListener(new View.OnTouchListener() 
            @Override
            public boolean onTouch(View v, MotionEvent event) 
                int x = (int)event.getRawX();
                int y = (int)event.getRawY();
                if(event.getAction() == MotionEvent.ACTION_UP)
                    if(isViewInBounds(btn2, x, y))
                        btn2.dispatchTouchEvent(event);
                    else if(isViewInBounds(btn1, x, y))
                        Log.d("Panauti", "onTouch ViewA");
                        //Here goes code to execute on onTouch ViewA
                    
                
                // Further touch is not handled
                return false;
            
        );

        btn2.setOnClickListener(new View.OnClickListener() 
            @Override
            public void onClick(View v) 
        );

        btn2.setOnTouchListener(new View.OnTouchListener() 
            @Override
            public boolean onTouch(View v, MotionEvent event) 
                int x = (int)event.getRawX();
                int y = (int)event.getRawY();
                if(event.getAction() == MotionEvent.ACTION_UP)
                    if(isViewInBounds(btn1, x, y))
                        btn1.dispatchTouchEvent(event);
                    else if(isViewInBounds(btn2, x, y))
                        Log.d("Panauti", "onTouch ViewB");
                        //Here goes code to execute on onTouch ViewB
                    
                
                // Further touch is not handled
                return false;
            
        );
    

    private boolean isViewInBounds(View view, int x, int y)
        view.getDrawingRect(outRect);
        view.getLocationOnScreen(location);
        outRect.offset(location[0], location[1]);
        return outRect.contains(x, y);
    

和activity_main.xml：

<?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:layout_
    android:layout_
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/txtresult"
        android:layout_
        android:layout_
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="102dp"
        android:textColor="@android:color/holo_red_dark"
        android:textSize="30sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/btn1"
        android:layout_
        android:layout_
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="25dp"
        android:text="A" />

    <TextView
        android:id="@+id/btn2"
        android:layout_
        android:layout_
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="160dp"
        android:text="B" />


</RelativeLayout>

请帮忙。提前致谢。

【问题讨论】：

您是否尝试过创建一个包含四个TextViews 的RelativeLayout，然后将onTouchListener 设置为RelativeLayout？我在回答中详细说明了

你的回答不完整且肤浅。

能否详细说明或编辑一下？

【参考方案1】：

我建议制作一个包含四个TextViews 的布局，然后为包含它们的布局设置一个onTouchListener。这样，只要触摸布局而不是特定按钮，它就可以绘制一条线，并且可以在视图之间迁移：

private int startX, startY, endX, endY; // fields to determine the coordinates of the Rect
layout.setOnTouchListener(new View.OnTouchListener() 
    @Override
    public boolean onTouch(View v, MotionEvent event) 
        if (event.getAction() == MotionEvent.ACTION_DOWN) 
            startX = event.getRawX();
            startY = event.getRawY();
         else 
            endX = event.getRawX();
            endY = event.getRawY();
            // set line bounds
        
    
);