圖片按鈕點擊事件不起作用

Question

我已經創建了一個用於測試和研究目的的小程序。 它由一個圖像按鈕組成，其作用是在按下圖像按鈕的同時顯示吐司。

我已更改了所有內容，但吐司消息未顯示。 代碼中沒有單個錯誤或警告。

昨天，我在這里發布了代碼，但沒有得到答案。

所以這次我上傳了源代碼。 希望有人可以解決這個簡單的解決方案。

https://drive.google.com/file/d/0B6Ax58vO7SvZcGRwNFlyYzhqZFk/view?usp=sharing

Answer 1

只需從內容中刪除此代碼並將其放在MainActivity.java中

public void onClick(View v) {
    switch (v.getId()) {
        case R.id.imageButton:
            Toast.makeText(getApplicationContext(),"You download is resumed",Toast.LENGTH_LONG).show();
            break;
    }
}

謹記

如果在布局文件（xml）中設置任何onClick事件，則必須在將使用該布局的父活動中創建方法。

這是完整的代碼。

<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_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="switchmode.lteonly.lteonlyswitch.MainActivity"
tools:showIn="@layout/app_bar_main">

<ImageButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/imageButton"

    android:clickable="true"
    android:layout_centerVertical="true"
    android:layout_centerInParent="true"
    android:src="@drawable/myimage"
    android:onClick="onClick"/>

MainActivity.java

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

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);
}

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

@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;
}

@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);
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();

    if (id == R.id.nav_camera) {
        // Handle the camera action
    } else if (id == R.id.nav_gallery) {

    } else if (id == R.id.nav_slideshow) {

    } else if (id == R.id.nav_manage) {

    } else if (id == R.id.nav_share) {

    } else if (id == R.id.nav_send) {

    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.imageButton:
            Toast.makeText(getApplicationContext(),"You download is resumed",Toast.LENGTH_LONG).show();
            break;
    }
}

}

Contentmain.java

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.content_main);
    ImageButton imgButton =(ImageButton)findViewById(R.id.imageButton);
  //  imgButton.setOnClickListener(this);
}