单击时Android Java按钮图像更改

Question

I cant seem to get my code to work. I keep getting a error.

I made a selector.xml with this code

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true"
        android:drawable="@drawable/loginbuttondn" />
    <item android:state_selected="false"
        android:drawable="@drawable/loginbutton" />
</selector>

heres my actual code

package monaiz.net.periscope.periscope;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.MotionEvent;
import android.view.View.OnTouchListener;



public class MainActivity extends AppCompatActivity implements OnTouchListener {

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


    }
    public boolean onTouch(View v, MotionEvent event) {
        int action = event.getAction();
        switch (action) {
            v.setOnTouchListener(new OnTouchListener() {
                @Override
                public boolean onTouch(View arg0, MotionEvent arg1) {

                    v.setSelected(arg1.getAction()==MotionEvent.ACTION_DOWN);
                    return true;
                }
            });

        }
        return true;
    }


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

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

Im trying to get it so that when i click the button it has a click down effect showing the other image

Im getting a error here:

Im still getting a error on this line v.setSelected(arg1.getAction()==MotionEvent.ACTION_DOWN);

on the "v."

code for my button

 <ImageView
        android:layout_width="280dp"
        android:layout_height="90dp"
        android:layout_marginTop="830px"
        android:layout_marginLeft="55dp"
        android:src="@drawable/loginbutton"/>

Answer 1

Use state_pressed :

drawable/selector.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true"
        android:drawable="@drawable/loginbuttondn" />
    <item
        android:drawable="@drawable/loginbutton" />
</selector>

---

<Button
    android:layout_width="280dp"
    android:layout_height="90dp"
    android:background="@drawable/selector"/>

Answer 2

Your selector needs to look like this:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true"
        android:drawable="@drawable/loginbuttondn" />
    <item android:drawable="@drawable/loginbutton" />
</selector>

Call this login_button_selector.xml and put it in your /res/drawable folder
Now use it like this:

<ImageView
        android:layout_width="280dp"
        android:layout_height="90dp"
        android:layout_marginTop="830px"
        android:layout_marginLeft="55dp"
        android:src="@drawable/login_button_selector"/>

When the view is in "pressed" state, it will match the first item in the selector. When it is not in "pressed" state, it will just match the second item in the selector.