Android 为什么当我点击按钮时我的程序会崩溃？

我正在做我的计算机课程作业，每次我尝试运行我的应用程序并进行此活动时，它就会崩溃，并说不幸的是，活动已停止。如果我从第（------）行删除代码的最后一部分，活动就会出现并工作。但是有了它，它就不起作用了。有人知道为什么会这样吗？我该如何解决

    import android.os.Bundle;
    import android.support.v7.app.AppCompatActivity;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.ArrayAdapter;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.LinearLayout;
    import android.widget.Spinner;
    import android.widget.TextView;

    public class BedroomDoorSigns extends AppCompatActivity {
        private String[] wood;
        private Spinner spinner;
        private String[] colour;
        private String[] size;
        private Button mButton;
        private LinearLayout mLayout;
        private EditText mEditText;


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

            wood = getResources().getStringArray(R.array.wood_list);
            spinner = (Spinner) findViewById(R.id.wood_spinner);
            colour = getResources().getStringArray(R.array.colour_list);
            spinner = (Spinner) findViewById(R.id.colour_spinner);
            size = getResources().getStringArray(R.array.size_list);
            spinner = (Spinner) findViewById(R.id.size_spinner);
            Button Buttons = (Button) findViewById(R.id.Cart);
            mLayout = (LinearLayout) findViewById(R.id.linearLayout);
            mEditText = (EditText) findViewById(R.id.editText);
            mButton = (Button) findViewById(R.id.button);
            mButton.setOnClickListener(onClick());
            TextView textView = new TextView(this);
            textView.setText("New text");


            ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, wood);
            dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            spinner.setAdapter(dataAdapter);

            ArrayAdapter<String> dataAdapter2 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, colour);
            dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            spinner.setAdapter(dataAdapter2);

            ArrayAdapter<String> dataAdapter3 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, size);
            dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            spinner.setAdapter(dataAdapter3);

        }

谢谢

像这样试试

mButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mLayout.addView(createNewTextView(mEditText.getText().toString()));
        }
    });

像这样试试

mButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mLayout.addView(createNewTextView(mEditText.getText().toString()));
        }
    });

java.lang.NullPointerException：尝试在com.example.emily.activity414timber.BedroomDoorSigns.onCreate（BedroomDoorSigns.java:41）上的空对象引用上调用虚拟方法“void android.widget.Button.setOnClickListener（android.view.view$OnClickListener）”

您的button对象（mButton）为null，因此当您对该对象调用“setOnclickListner”方法时，它会抛出“nullpointerexception”

java.lang.NullPointerException：尝试在com.example.emily.activity414timber.BedroomDoorSigns.onCreate（BedroomDoorSigns.java:41）上的空对象引用上调用虚拟方法“void android.widget.Button.setOnClickListener（android.view.view$OnClickListener）”

---

您的button对象（mButton）为空，因此当您对该对象调用“setOnclickListner”方法时，它会抛出“nullpointerexception”

@09Emi，请发布您的logcat@09Emi，请张贴您的日志