public class MainActivity extends AppCompatActivity {
에러메세지E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.example.user.mycmf, PID: 2336
                  java.lang.IllegalStateException: Could not execute method for android:onClick

at android.view.View$DeclaredOnClickListener.onClick(View.java:4698)
                      at android.view.View.performClick(View.java:5610)
                      at android.view.View$PerformClick.run(View.java:22265)
                      at android.os.Handler.handleCallback(Handler.java:751)
                      at android.os.Handler.dispatchMessage(Handler.java:95)
                      at android.os.Looper.loop(Looper.java:154)
                      at android.app.ActivityThread.main(ActivityThread.java:6077)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
                   Caused by: java.lang.reflect.InvocationTargetException
                      at java.lang.reflect.Method.invoke(Native Method)
                      at android.view.View$DeclaredOnClickListener.onClick(View.java:4693)
                      at android.view.View.performClick(View.java:5610) 
                      at android.view.View$PerformClick.run(View.java:22265) 
                      at android.os.Handler.handleCallback(Handler.java:751) 
                      at android.os.Handler.dispatchMessage(Handler.java:95) 
                      at android.os.Looper.loop(Looper.java:154) 
                      at android.app.ActivityThread.main(ActivityThread.java:6077) 
                      at java.lang.reflect.Method.invoke(Native Method)

Caused by: android.content.res.Resources$NotFoundException: String resource ID #0x0
                      at android.content.res.Resources.getText(Resources.java:331)
                      at android.content.res.Resources.getString(Resources.java:377)
                      at com.example.user.mycmf.MainActivity.call(MainActivity.java:27)
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at android.view.View$DeclaredOnClickListener.onClick(View.java:4693) 
                      at android.view.View.performClick(View.java:5610) 
                      at android.view.View$PerformClick.run(View.java:22265) 
                      at android.os.Handler.handleCallback(Handler.java:751) 
                      at android.os.Handler.dispatchMessage(Handler.java:95) 
                      at android.os.Looper.loop(Looper.java:154) 
                      at android.app.ActivityThread.main(ActivityThread.java:6077) 
                      at java.lang.reflect.Method.invoke(Native Method) 

메인액티비티
@Override
 protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void call(View v) {
int id = v.getId();
LinearLayout layout = (LinearLayout) v.findViewById(id);
String tag = (String) layout.getTag();

Resources res = getResources();

int id_tel = res.getIdentifier("tel" + tag, "string", getPackageName());

String tel = res.getString(id_tel);

Uri number = Uri.parse("tel:" + tel);
Intent intent = new Intent(Intent.ACTION_CALL,number);
startActivity(intent);
}
}

스트링.xml

<string name="app_name">전화 걸기</string>
<string name="name01">장발장</string>
<string name="addr01">서울</string>
<string name="tel01">010-0000-1111</string>
<string name="tel02">000-0001-1112</string>
<string name="name02">코제트</string>
<string name="addr02">부산</string>


몇시간째 고쳐보는데도 작동할 생각을 안합니다 ㅜㅜ 뭐가 문제일까요