Android：單擊按鈕后無法設置圖像（NullpointerException / IllegalStateException）

Question

單擊imageview（應用程序崩潰）后，我得到一個IllegalStateException和NullPointerException。 應該將imageview的圖像傳遞到另一個imageview。 我還在選項卡式活動中使用了一個片段。

onCreate（）和變量

private SectionsPagerAdapter mSectionsPagerAdapter;
private ViewPager mViewPager;
PhotoViewAttacher xAttach;
ImageView tessst;

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.activity_whole_details);

    tessst = (ImageView) findViewById(R.id.fillZoom);
    what = (ImageView) findViewById(R.id.img1);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

    mViewPager = (ViewPager) findViewById(R.id.container);
    mViewPager.setAdapter(mSectionsPagerAdapter);

    TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
    tabLayout.setupWithViewPager(mViewPager);

}

Imageview點擊類

    public void clickZoom(View v){
    if(v.getId() == R.id.img1){
        Drawable bb = getResources().getDrawable(R.drawable.maincolor_btn);
        tessst.setImageDrawable(bb);
        xAttach = new PhotoViewAttacher(tessst);
    }
}

日志貓

09-06 13:12:45.436 31388-31388/com.example.testapp.coloranalysis E/AndroidRuntime: FATAL EXCEPTION: main
               Process: com.example.testapp.coloranalysis, PID: 31388
               java.lang.IllegalStateException: Could not execute method for android:onClick
                   at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
                   at android.view.View.performClick(View.java:4463)
                   at android.view.View$PerformClick.run(View.java:18770)
                   at android.os.Handler.handleCallback(Handler.java:808)
                   at android.os.Handler.dispatchMessage(Handler.java:103)
                   at android.os.Looper.loop(Looper.java:193)
                   at android.app.ActivityThread.main(ActivityThread.java:5323)
                   at java.lang.reflect.Method.invokeNative(Native Method)
                   at java.lang.reflect.Method.invoke(Method.java:515)
                   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824)
                   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
                   at dalvik.system.NativeStart.main(Native Method)
                Caused by: java.lang.reflect.InvocationTargetException
                   at java.lang.reflect.Method.invokeNative(Native Method)
                   at java.lang.reflect.Method.invoke(Method.java:515)
                   at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
                   at android.view.View.performClick(View.java:4463) 
                   at android.view.View$PerformClick.run(View.java:18770) 
                   at android.os.Handler.handleCallback(Handler.java:808) 
                   at android.os.Handler.dispatchMessage(Handler.java:103) 
                   at android.os.Looper.loop(Looper.java:193) 
                   at android.app.ActivityThread.main(ActivityThread.java:5323) 
                   at java.lang.reflect.Method.invokeNative(Native Method) 
                   at java.lang.reflect.Method.invoke(Method.java:515) 
                   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824) 
                   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640) 
                   at dalvik.system.NativeStart.main(Native Method) 
                Caused by: java.lang.NullPointerException
                   at com.example.testapp.coloranalysis.WholeDetails.clickZoom(WholeDetails.java:59)
                   at java.lang.reflect.Method.invokeNative(Native Method) 
                   at java.lang.reflect.Method.invoke(Method.java:515) 
                   at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) 
                   at android.view.View.performClick(View.java:4463) 
                   at android.view.View$PerformClick.run(View.java:18770) 
                   at android.os.Handler.handleCallback(Handler.java:808) 
                   at android.os.Handler.dispatchMessage(Handler.java:103) 
                   at android.os.Looper.loop(Looper.java:193) 
                   at android.app.ActivityThread.main(ActivityThread.java:5323) 
                   at java.lang.reflect.Method.invokeNative(Native Method) 
                   at java.lang.reflect.Method.invoke(Method.java:515) 
                   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824) 
                   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640) 
                   at dalvik.system.NativeStart.main(Native Method) 

Answer 1

也許tessst為空。

因此R.id.fillZoom可能不在R.layout.activity_whole_details

您可以移動tessst = (ImageView) findViewById(R.id.fillZoom); 片段中的onCreateView，當然也必須移動與tessst相關的代碼。

Answer 2

我假定您正在以屬性android：onClick =“ clickZoom”添加XML中的onClick偵聽器。 現在要做的是， clickZoom函數必須是Activity類的一部分，聽起來好像不是。
您需要做的是刪除XML屬性，並通過使類實現View.OnClickListener接口並在視圖上調用setOnClickListener來在代碼中設置onClick偵聽器。