我正在制作一个提供拨号器功能的应用程序。我创建了一个键盘,并在其后面提供了键盘功能。它应该检测来电,使用telephonyManager拨打电话等。但是当我运行代码时,它会出现以下错误:
抱歉,com.maju.yourApp已经无意中停止了
我的代码中没有任何错误,我不知道原因。有人可以确定问题的原因吗?我正在尝试的代码如下:
公共类MainActivity扩展了Activity {
EditText ed =(EditText) findViewById(R.id.editText1);
String number;
Intent intent;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
PhoneCallListener listenerObj = new PhoneCallListener();
TelephonyManager tm = (TelephonyManager) this.getSystemService(Context.TELEPHONY_SERVICE);
tm.listen(listenerObj,PhoneStateListener.LISTEN_CALL_STATE);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
public void one_btn(View v)
{
number = number+"1";
ed.setText(number);
}
public void two_btn(View v)
{
number = number+"2";
ed.setText(number);
}
public void three_btn(View v)
{
number = number+"3";
ed.setText(number);
}
public void four_btn(View v)
{
number = number+"4";
ed.setText(number);
}
public void five_btn(View v)
{
number = number+"5";
ed.setText(number);
}
public void six_btn(View v)
{
number = number+"6";
ed.setText(number);
}
public void seven_btn(View v)
{
number = number+"7";
ed.setText(number);
}
public void eight_btn(View v)
{
number = number+"8";
ed.setText(number);
}
public void nine_btn(View v)
{
number = number+"9";
ed.setText(number);
}
public void esterisk_btn(View v)
{
number = number+"*";
ed.setText(number);
}
public void zero_btn(View v)
{
number = number+"0";
ed.setText(number);
}
public void hash_btn(View v)
{
number = number+"#";
ed.setText(number);
}
public void call_btn(View v)
{
intent = new Intent(Intent.ACTION_CALL);
intent.setData(Uri.parse("tel:" + number));
startActivity(intent);
}
public void back_btn(View v)
{
if(number.length() > 0)
{
String temp = "";
for(int i=0; i<number.length() - 1; i++)
{
temp += number.charAt(i);
}
number = temp;
}
}
private class PhoneCallListener extends PhoneStateListener
{
long start;
long end;
Context context = getApplicationContext();
Toast toast;
boolean flag = false;
public void onCallStateChanged(int state, String incomingNumber)
{
if(TelephonyManager.CALL_STATE_OFFHOOK == state)
{
start = System.currentTimeMillis();
Log.i("Log" , "Phone State Calling");
toast = Toast.makeText(context, "Phone State Calling" , Toast.LENGTH_LONG);
toast.show();
flag = true;
}
else if(TelephonyManager.CALL_STATE_IDLE == state)
{
Log.i("Log" , "Phone State Idle");
toast = Toast.makeText(context, "Phon State Idle", Toast.LENGTH_LONG);
toast.show();
if(flag)
{
end = System.currentTimeMillis();
long duration = (end - start)/1000;
Log.i("Log" , "Call Ended, Duration: "+ duration);
toast = Toast.makeText(context, "Call Ended\n Duration: "+ duration, Toast.LENGTH_LONG);
toast.show();
flag = false;
}
}
else if(TelephonyManager.CALL_STATE_RINGING == state)
{
Log.i("Log", "Incoming Call From " + incomingNumber);
toast = Toast.makeText(context, "Incoming Call: "+ incomingNumber, Toast.LENGTH_LONG);
toast.show();
}
}
}
}
答案 0 :(得分:1)
你的问题在这里:
EditText ed =(EditText) findViewById(R.id.editText1);
在使用setContentView之前,不能使用findViewById。
在setContentView()之后将此行移动到onCreate。
在他的未来,不要思考&#34;我在代码中没有任何错误&#34;。你的意思是编译器没有向你显示任何错误,但你确实有(至少)一个错误。这是一个重要的观点,因为如果您有任何错误,编译错误只是解决问题的第一步。在询问崩溃时,请发布logcat堆栈跟踪作为习惯问题。我打赌你的人会显示一个&#34;空指针异常&#34;。