【问题标题】:onClick listener does not function - breakpoint cannot be reachedonClick 侦听器不起作用 - 无法到达断点
【发布时间】:2013-12-07 17:44:47
【问题描述】:

我正在尝试设置一个 onclick 侦听器以在单击按钮后更改按钮的背景。我的问题是当我在它的 onClick 方法设置断点时,使用调试器无法访问它。我相信这可能是一个语法问题 - 但我已经看过好几次了,似乎无法发现如何解决它。

非常感谢任何帮助。

提前致谢,

Java新手

源代码段:

public void onClick(View v) {
        if (v == fav_up_btn) {
            fav_up_btn.setBackgroundResource(R.drawable.fav_dwn_btn);
        }

    }

来源:

public class Home extends YouTubeBaseActivity implements
        YouTubePlayer.OnInitializedListener,
        YouTubeThumbnailView.OnInitializedListener {

    public static final String API_KEY = "AIzaSyC0Te2pyooXzuyLaE6_SsFlITKCwjj55fI";
    public static final String VIDEO_ID = "o7VVHhK9zf0";
    public static final String VIDEO1_ID = "xVHHJqntuXI";
    public static final String VIDEO2_ID = "YWteQj_q3Ro";

    private YouTubePlayer youTubePlayer;
    private YouTubePlayerView youTubePlayerView;
    private YouTubeThumbnailView youTubeThumbnailView1;
    private YouTubeThumbnailView youTubeThumbnailView2;
    private YouTubeThumbnailView youTubeThumbnailView3;
    private YouTubeThumbnailView youTubeThumbnailView4;

    private YouTubeThumbnailLoader youTubeThumbnailLoader;
    ScrollView mainScrollView;
    Button fav_up_btn;

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

        youTubePlayerView = (YouTubePlayerView) findViewById(R.id.youtubeplayerview);
        youTubePlayerView.initialize(API_KEY, this);

        mainScrollView = (ScrollView) findViewById(R.id.groupScrollView);

        youTubeThumbnailView1 = (YouTubeThumbnailView) findViewById(R.id.youtubethumbnailview1);
        youTubeThumbnailView1.initialize(API_KEY, this);
        fav_up_btn = (Button)findViewById(R.id.fav_up_btn);

        fav_up_btn.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                if (v == fav_up_btn) {
                    fav_up_btn.setBackgroundResource(R.drawable.fav_dwn_btn);
                }
            }
        });

        youTubeThumbnailView1.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                if (youTubePlayer != null) {
                    youTubePlayer.cueVideo(VIDEO1_ID);
                    youTubePlayer.play();
                    mainScrollView.smoothScrollTo(0, 0);
                }
            }
        });

        youTubeThumbnailView2 = (YouTubeThumbnailView) findViewById(R.id.youtubethumbnailview2);
        youTubeThumbnailView2.initialize(API_KEY, this);

        youTubeThumbnailView2.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg1) {
                if (youTubePlayer != null) {
                    youTubePlayer.cueVideo(VIDEO1_ID);
                    youTubePlayer.play();
                    mainScrollView.smoothScrollTo(0, 0);
                }
            }
        });

        youTubeThumbnailView3 = (YouTubeThumbnailView) findViewById(R.id.youtubethumbnailview3);
        youTubeThumbnailView3.initialize(API_KEY, this);

        youTubeThumbnailView3.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg1) {
                if (youTubePlayer != null) {
                    youTubePlayer.cueVideo(VIDEO1_ID);
                    youTubePlayer.play();
                    mainScrollView.smoothScrollTo(0, 0);
                }
            }
        });

        youTubeThumbnailView4 = (YouTubeThumbnailView) findViewById(R.id.youtubethumbnailview4);
        youTubeThumbnailView4.initialize(API_KEY, this);

        youTubeThumbnailView4.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg1) {
                if (youTubePlayer != null) {
                    youTubePlayer.cueVideo(VIDEO1_ID);
                    youTubePlayer.play();
                    mainScrollView.smoothScrollTo(0, 0);
                }
            }

        });


    }

    @Override
    public void onInitializationFailure(Provider provider,
            YouTubeInitializationResult result) {

    }

    @Override
    public void onInitializationSuccess(Provider provider,
            YouTubePlayer player, boolean wasRestored) {

        youTubePlayer = player;

        if (!wasRestored) {
            player.cueVideo(VIDEO_ID);
        }
    }

    @Override
    public void onInitializationFailure(YouTubeThumbnailView thumbnailView,
            YouTubeInitializationResult error) {

    }

    @Override
    public void onInitializationSuccess(YouTubeThumbnailView thumbnailView,
            YouTubeThumbnailLoader thumbnailLoader) {

        youTubeThumbnailLoader = thumbnailLoader;
        thumbnailLoader
                .setOnThumbnailLoadedListener(new ThumbnailLoadedListener());

        youTubeThumbnailLoader.setVideo(VIDEO_ID);

    }

    private final class ThumbnailLoadedListener implements
            YouTubeThumbnailLoader.OnThumbnailLoadedListener {

        @Override
        public void onThumbnailError(YouTubeThumbnailView arg0, ErrorReason arg1) {

        }

        @Override
        public void onThumbnailLoaded(YouTubeThumbnailView arg0, String arg1) {

        }

    }

}

XML:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:textStyle="bold" />

    <ScrollView
        android:id="@+id/groupScrollView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical" >

            <com.google.android.youtube.player.YouTubePlayerView
                android:id="@+id/youtubeplayerview"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >

                <TextView
                    android:id="@+id/textView1a"
                    android:layout_width="0dip"
                    android:layout_height="wrap_content"
                    android:layout_weight="1"
                    android:text="Throw &apos;Em Up"
                    android:textAppearance="?android:attr/textAppearanceMedium" />

                <Button
                    android:id="@+id/fav_up_btn"
                    android:layout_width="27dp"
                    android:layout_height="27dp"
                    android:layout_alignParentTop="true"
                    android:layout_toRightOf="@+id/textView1a"
                    android:background="@drawable/fav_up_btn"
                    android:gravity="right"
                    android:paddingRight="5dp"
                    android:paddingTop="5dp" />

                <selector>

                    <item
                        android:drawable="@drawable/fav_up_btn"
                        android:state_focused="true"
                        android:state_pressed="false"/>

                    <item
                        android:drawable="@drawable/fav_dwn_btn"
                        android:state_focused="true"
                        android:state_pressed="true"/>

                    <item
                        android:drawable="@drawable/fav_dwn_btn"
                        android:state_focused="false"
                        android:state_pressed="true"/>

                    <item android:drawable="@drawable/fav_up_btn"/>
                </selector>
            </LinearLayout>

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >

                <TextView
                    android:id="@+id/textView2a"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_toLeftOf="@+id/textView3a"
                    android:gravity="left"
                    android:text="by DJ Generic  |"
                    android:textAppearance="?android:attr/textAppearanceSmall"
                    android:textColor="@color/lightgrey" />

                <TextView
                    android:id="@+id/textView3a"
                    android:layout_width="0dp"
                    android:layout_height="wrap_content"
                    android:layout_weight="1"
                    android:gravity="left"
                    android:text="  100,000 views"
                    android:textAppearance="?android:attr/textAppearanceSmall" />
            </LinearLayout>

            <View
                android:layout_width="1dp"
                android:layout_height="25dp" >
            </View>

            <com.google.android.youtube.player.YouTubeThumbnailView
                android:id="@+id/youtubethumbnailview1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" />

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >

                <TextView
                    android:id="@+id/textView1a"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight="1"
                    android:text="Bulls On Parade"
                    android:textAppearance="?android:attr/textAppearanceMedium" />

                <Button
                    android:id="@+id/fav_up_btn"
                    android:layout_width="27dp"
                    android:layout_height="27dp"
                    android:layout_alignParentTop="true"
                    android:layout_toRightOf="@+id/textView1a"
                    android:background="@drawable/fav_up_btn"
                    android:gravity="right"
                    android:paddingRight="5dp"
                    android:paddingTop="5dp" />
            </LinearLayout>

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >

                <TextView
                    android:id="@+id/textView2a"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_toLeftOf="@+id/textView3a"
                    android:gravity="left"
                    android:text="by Rage Against The Machine  |"
                    android:textAppearance="?android:attr/textAppearanceSmall"
                    android:textColor="@color/lightgrey" />

                <TextView
                    android:id="@+id/textView3a"
                    android:layout_width="0dp"
                    android:layout_height="wrap_content"
                    android:layout_weight="1"
                    android:gravity="left"
                    android:text="  100,000 views"
                    android:textAppearance="?android:attr/textAppearanceSmall" />
            </LinearLayout>

            <View
                android:layout_width="1dp"
                android:layout_height="25dp" >
            </View>

            <com.google.android.youtube.player.YouTubeThumbnailView
                android:id="@+id/youtubethumbnailview2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" />

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >

                <TextView
                    android:id="@+id/textView1a"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight="1"
                    android:text="Isaac Daniel on CNN with Anderson Cooper"
                    android:textAppearance="?android:attr/textAppearanceMedium" />

                <Button
                    android:id="@+id/fav_up_btn"
                    android:layout_width="27dp"
                    android:layout_height="27dp"
                    android:layout_alignParentTop="true"
                    android:layout_toRightOf="@+id/textView1a"
                    android:background="@drawable/fav_up_btn"
                    android:gravity="right"
                    android:paddingRight="5dp"
                    android:paddingTop="5dp" />
            </LinearLayout>

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >

                <TextView
                    android:id="@+id/textView2a"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_toLeftOf="@+id/textView3a"
                    android:gravity="left"
                    android:text="by idconex  |"
                    android:textAppearance="?android:attr/textAppearanceSmall"
                    android:textColor="@color/lightgrey" />

                <TextView
                    android:id="@+id/textView3a"
                    android:layout_width="0dp"
                    android:layout_height="wrap_content"
                    android:layout_toRightOf="@+id/textView2a"
                    android:layout_weight="1"
                    android:gravity="left"
                    android:text="  100,000 views"
                    android:textAppearance="?android:attr/textAppearanceSmall" />
            </LinearLayout>

            <View
                android:layout_width="1dp"
                android:layout_height="25dp" >
            </View>

            <com.google.android.youtube.player.YouTubeThumbnailView
                android:id="@+id/youtubethumbnailview3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" />

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >

                <TextView
                    android:id="@+id/textView1a"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight="1"
                    android:text="Bulls On Parade"
                    android:textAppearance="?android:attr/textAppearanceMedium" />

                <Button
                    android:id="@+id/fav_up_btn"
                    android:layout_width="27dp"
                    android:layout_height="27dp"
                    android:layout_alignParentTop="true"
                    android:layout_toRightOf="@+id/textView1a"
                    android:background="@drawable/fav_up_btn"
                    android:gravity="right"
                    android:paddingRight="5dp"
                    android:paddingTop="5dp" />
            </LinearLayout>

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >

                <TextView
                    android:id="@+id/textView2a"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_toLeftOf="@+id/textView3a"
                    android:gravity="left"
                    android:text="by Rage Against The Machine  |"
                    android:textAppearance="?android:attr/textAppearanceSmall"
                    android:textColor="@color/lightgrey" />

                <TextView
                    android:id="@+id/textView3a"
                    android:layout_width="0dp"
                    android:layout_height="wrap_content"
                    android:layout_weight="1"
                    android:gravity="left"
                    android:text="  100,000 views"
                    android:textAppearance="?android:attr/textAppearanceSmall" />
            </LinearLayout>

            <View
                android:layout_width="1dp"
                android:layout_height="25dp" >
            </View>

            <com.google.android.youtube.player.YouTubeThumbnailView
                android:id="@+id/youtubethumbnailview4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" />

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >

                <TextView
                    android:id="@+id/textView1a"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight="1"
                    android:text="Isaac Daniel on CNN with Anderson Cooper"
                    android:textAppearance="?android:attr/textAppearanceMedium" />

                <Button
                    android:id="@+id/fav_up_btn"
                    android:layout_width="27dp"
                    android:layout_height="27dp"
                    android:layout_alignParentTop="true"
                    android:layout_toRightOf="@+id/textView1a"
                    android:background="@drawable/fav_up_btn"
                    android:gravity="right"
                    android:paddingRight="5dp"
                    android:paddingTop="5dp" />
            </LinearLayout>

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >

                <TextView
                    android:id="@+id/textView2a"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_toLeftOf="@+id/textView3a"
                    android:gravity="left"
                    android:text="by idconex  |"
                    android:textAppearance="?android:attr/textAppearanceSmall"
                    android:textColor="@color/lightgrey" />

                <TextView
                    android:id="@+id/textView3a"
                    android:layout_width="0dp"
                    android:layout_height="wrap_content"
                    android:layout_weight="1"
                    android:gravity="left"
                    android:text="  100,000 views"
                    android:textAppearance="?android:attr/textAppearanceSmall" />
            </LinearLayout>

            <View
                android:layout_width="1dp"
                android:layout_height="5dp" >
            </View>
        </LinearLayout>
    </ScrollView>

</LinearLayout>

结果:

11-22 13:46:00.015: E/AndroidRuntime(21880): FATAL EXCEPTION: main
11-22 13:46:00.015: E/AndroidRuntime(21880): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.idg2/com.idg.omv.Home}: android.view.InflateException: Binary XML file line #56: Error inflating class selector
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2110)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.app.ActivityThread.access$700(ActivityThread.java:140)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1237)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.os.Handler.dispatchMessage(Handler.java:99)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.os.Looper.loop(Looper.java:137)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.app.ActivityThread.main(ActivityThread.java:4921)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at java.lang.reflect.Method.invokeNative(Native Method)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at java.lang.reflect.Method.invoke(Method.java:511)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at dalvik.system.NativeStart.main(Native Method)
11-22 13:46:00.015: E/AndroidRuntime(21880): Caused by: android.view.InflateException: Binary XML file line #56: Error inflating class selector
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:698)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:313)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.app.Activity.setContentView(Activity.java:1924)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at com.idg.omv.Home.onCreate(Home.java:43)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.app.Activity.performCreate(Activity.java:5206)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)
11-22 13:46:00.015: E/AndroidRuntime(21880):    ... 11 more
11-22 13:46:00.015: E/AndroidRuntime(21880): Caused by: java.lang.ClassNotFoundException: android.view.selector
11-22 13:46:00.015: E/AndroidRuntime(21880):    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.view.LayoutInflater.createView(LayoutInflater.java:552)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.view.LayoutInflater.onCreateView(LayoutInflater.java:643)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.view.LayoutInflater.onCreateView(LayoutInflater.java:660)
11-22 13:46:00.015: E/AndroidRuntime(21880):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:685)
11-22 13:46:00.015: E/AndroidRuntime(21880):    ... 24 more
11-22 13:46:11.205: I/Process(21880): Sending signal. PID: 21880 SIG: 9

【问题讨论】:

  • 我没有看到您设置按钮或其点击监听器的任何地方
  • 按钮 fav_up_btn;和 public void onClick(View v) { if (v == fav_up_btn) { fav_up_btn.setBackgroundResource(R.drawable.fav_dwn_btn); }
  • 您是否使用 xml 将按钮链接到 onClick() 方法?如果是这样,您应该发布 xml 文件。此外,您没有回答来自 tyczj 的推断问题,因此我将更详细地解释一下。在发布的代码中,您永远不会调用fav_up_btn = new Button(this);,也不会调用fav_up_btn.setOnClickListener(...);。如果您使用 xml 来执行此操作,请发布 xml,否则没有人可以提供帮助
  • 道歉 - 我更新了我的源代码以包含它(但它仍然无法正常工作)
  • @user3009687 你的其他点击方法有效吗?

标签: java android onclick onclicklistener buttonclick


【解决方案1】:

如果您在 xml 中定义了按钮,请在 onCreate() 中的某处添加代码:

fav_up_btn = (Button)findViewById(R.id.fav_up_btn);

然后设置您的点击监听器。如果您在 xml 中没有按钮,并且您想在更新的代码中创建它(fav_up_btn = new Button(this)),您需要稍后将其添加到布局中。如果您在 xml 中定义了布局,请添加一个 id,如果它不存在:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@id/myLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

然后,添加按钮,你可以这样做:

LinearLayout layout = (LinearLayout) findViewById(R.id.myLayout);

layout.addView(fav_up_btn);

或类似(现在在代码中创建按钮的方式):

LinearLayout layout = (LinearLayout) findViewById(R.id.myLayout);

Button fav_up_btn = new Button(this);
fav_up_btn.setText(roomName);
fav_up_btn.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,         LayoutParams.WRAP_CONTENT));
layout.addView(fav_up_btn);

请记住在任何一种情况下都设置点击监听器。

【讨论】:

  • 我尝试实施您的答案,但遇到强制关闭错误(请参阅上面的更新说明)
【解决方案2】:
fav_up_btn.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v) {
        if (v == fav_up_btn) {
            fav_up_btn.setBackgroundResource(R.drawable.fav_dwn_btn);
        }
    }
});

为什么您在侦听器中有条件,如果您将相同的侦听器用于其他按钮,那将是有意义的。 但在你的情况下,我不明白你为什么需要它。

试试这样,同时检查你的 logcat:

fav_up_btn = (Button)findViewById(R.id.fav_up_btn);
fav_up_btn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {       
        fav_up_btn.setBackgroundResource(R.drawable.fav_dwn_btn);
        Log.d("mylog","fav_up_btn is clicked");
    }
});


编辑:

我试图打开和关闭一个按钮

fav_up_btn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        boolean favIsUp = fav_up_btn.getBackground().getConstantState()
                                    .equals(getResources().getDrawable(R.drawable.fav_up_btn).getConstantState());  
        //set the background                            
        fav_up_btn.setBackgroundResource(favIsUp ? R.drawable.fav_dwn_btn : R.drawable.fav_up_btn);
    }
});

希望对你有所帮助。

【讨论】:

  • 太棒了!并做相反的事情(将它从 fav_dwn_btn 设置回 fav_up_btn)我会这样做: fav_dwn_btn = (Button)findViewById(R.id.fav_dwn_btn); fav_dwn_btn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { fav_dwn_btn.setBackgroundResource(R.drawable.fav_up_btn); } 对吗?
  • 您有 2 个不同的按钮,还是尝试使用单个按钮进行切换?
  • 我正在尝试打开和关闭一个按钮
  • @user3009687 这不是问题的答案 - 异常是由 XML 布局中的 &lt;selector&gt; 引起的,正如我在回答中所描述的那样,不是因为 OnClickListener 和if 语句。
【解决方案3】:

问题当然在于您的OnClickListener 按钮;-)

fav_up_btn.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v) {
        if (v == fav_up_btn) {
            fav_up_btn.setBackgroundResource(R.drawable.fav_dwn_btn);
        }
    }
});

您使用== 而不是Objectequals 方法将2 个Objects 相互比较,就好像它们是原始类型一样。

要检查点击的视图是否正确,您应该将视图的 id 与 xml 布局中的 id 进行比较,如下所示:

if (v.getId() == R.id.fav_up_btn)

此外,如果不需要检查,因为您为每个Button 使用了一个匿名侦听器,所以其他按钮永远不会被这个OnClickListener 捕获。

编辑:我看到你已经改变了你的问题(也添加了你的 XML 布局)。这当然会有所不同 - 这部分在您的 XML 布局文件中无效:

<selector>
    <item
        android:drawable="@drawable/fav_up_btn"
        android:state_focused="true"
        android:state_pressed="false"/>

    <item
        android:drawable="@drawable/fav_dwn_btn"
        android:state_focused="true"
        android:state_pressed="true"/>

    <item
        android:drawable="@drawable/fav_dwn_btn"
        android:state_focused="false"
        android:state_pressed="true"/>

    <item android:drawable="@drawable/fav_up_btn"/>
</selector>

选择器应该位于 drawable 文件夹中,并且应该在按钮的 XML 中引用,如下所示:android:background="@drawable/mySelector"

第二次编辑:只是为了澄清你看到的异常。当您的Activity 启动时,Android 会尝试“膨胀”您的 XML 布局 - 当它到达 &lt;selector&gt; 标记时,它会尝试像其他 XML 布局一样膨胀它 - XML 布局内的项目是视图或小部件等充气系统使应用程序崩溃,因为它不知道如何处理 &lt;selector&gt; 标签,因为它不是视图。

【讨论】:

  • 太棒了!并做相反的事情(将它从 fav_dwn_btn 设置回 fav_up_btn)我会这样做: fav_dwn_btn = (Button)findViewById(R.id.fav_dwn_btn); fav_dwn_btn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { fav_dwn_btn.setBackgroundResource(R.drawable.fav_up_btn); } 对吗?
  • 是的,我相信 ;-)
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