如何正确使用Android OnTouchListener和OnTouch功能？

Question

我的Android应用中有一个字符串生成器功能。我希望每次有“点击”或“触摸”时调用字符串生成器功能。然后，字符串生成器函数将更改文本标签中的字符串。我没有任何类型的错误，但是当我在Android模拟器和物理设备上测试应用程序时，文本标签中的字符串不会更改，这意味着不会调用字符串生成器函数。

以下是我的代码：

public class MainActivity extends Activity{

    //member variables
    private ExcuseGenerator mExcuseGenerator = new ExcuseGenerator();
    private ImageView mMrExcuse;
    private TextView mExcuse;
    private RelativeLayout rl;

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


        mMrExcuse = (ImageView) findViewById(R.id.imageView1);
        mExcuse = (TextView) findViewById(R.id.textView1);
        rl = (RelativeLayout) findViewById(R.id.rl1);

        rl.setOnTouchListener(
                new View.OnTouchListener(){
                    @Override
                    public boolean onTouch(View v, MotionEvent event) {
                        if(event.getAction() == MotionEvent.ACTION_UP){

                            //here is the string generator function
                            excuseGenerator();
                            return true;
                        }
                        return false;
                    }
                }
                );
    }

注意：我希望在屏幕上的任何位置检测点击/触摸，这就是我使用OnTouchListener的相对布局的原因。

编辑：添加了屏幕截图以显示XML文件。

编辑2：这是我的借口生成器功能：

private void excuseGenerator(){
        String excuse = mExcuseGenerator.getExcuse();
        mExcuse.setText(excuse); //mExcuse is a text label.
    }

以下是mExcuseGenerator类的getExcuse函数：

    /*
     * I want to create a "real random experience".
     * This function will have 2 lists. Every time an excuse is generated, 
     * it is deleted from its original array and then put into a temporary array
     * so that the same excuses are not to be seen over and over again. 
     * when the original array is emptied, it will be reassigned the set of excuses
     * and the temporary array will be emptied again. 
    */
    public String getExcuse(){

        if(stringArray.isEmpty()){
            stringArray = Arrays.asList(mExcuseList);
            tempHolder = null;
        }
        String excuse;
        Random randomGenerator =  new Random();

        // get the position of the element from the array
        int randomElement = randomGenerator.nextInt(stringArray.size());
        excuse = stringArray.get(randomElement);

        tempHolder.add(stringArray.get(randomElement));
        stringArray.remove(stringArray.get(randomElement));



        //return the element 
        return excuse;
    }

Answer 1

如果要在屏幕上的任何位置启用touchListener，请使用此方法OnTouchEvent(MotionEvent event)。

public class MainActivity extends Activity {

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


@Override
public boolean onTouchEvent(MotionEvent event)
{
    switch(event.getAction() & MotionEvent.ACTION_MASK)
{
    case MotionEvent.ACTION_DOWN : //Do something
                                    break;
    case MotionEvent.ACTION_UP : //Do something
                                    break;
    }
    return true;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

现在您不必检测特定视图的touchEvents。

Answer 2

请在ACTION_DOWN（http://developer.android.com/reference/android/view/MotionEvent.html#ACTION_DOWN）事件发生时尝试返回true。这是首次触发的事件，如果在这种情况下返回false，如果我没记错，则不会触发所有其他事件。

Answer 3

添加

android:clickable="true"

到你的布局的XML中的RelativeLayout。

<强> activity_main.xml中

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/clicks"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clickable="true"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/hello_world" />

</RelativeLayout>

并在你的java代码中， 的 MainActivity.java

package com.test.testing;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.RelativeLayout;
import android.widget.Toast;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            RelativeLayout click = (RelativeLayout) findViewById(R.id.clicks);

            click.setOnClickListener(new View.OnClickListener() {

                    @Override
                    public void onClick(View v) {
                            Toast.makeText(getApplicationContext(), "Testing", Toast.LENGTH_SHORT).show();
                    }
            });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
            // Inflate the menu; this adds items to the action bar if it is present.
            getMenuInflater().inflate(R.menu.main, menu);
            return true;
    }

}