安卓，点击了我同意，就崩溃了

Question

MainActivity.java

 package com.ample.receive;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.TextView;

public class MainActivity extends Activity implements OnClickListener{
    private TextView myTextView1;
    private TextView myTextView2;
    private CheckBox myCheckBox;
    private Button myButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        myCheckBox=(CheckBox)findViewById(R.id.myCheckBox);
        myCheckBox.setChecked(false);
        myCheckBox.setOnClickListener(this);
        myButton=(Button)findViewById(R.id.myButton);
        myButton.setEnabled(false);
        myButton.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.myCheckBox:
            if (myCheckBox.isChecked())
            {
                myButton.setEnabled(true);
                myTextView2.setText("abc");
            }
            else
            {
                myButton.setEnabled(false);
                myTextView1.setText(R.string.text);
                myTextView2.setText(R.string.no);
            }
            break;
        case R.id.myButton:
            if (myCheckBox.isChecked())
            {
                myTextView1.setText(R.string.ok);
            }
            break;
        default:break;
        }
    }

    @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();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

Answer 1

错误很明显，是空的对象，你的TextView在setText之前，要记得findviewbyId，否则就会出现这个错误。
myTextView1=(TextView)findViewById(R.id.myTextView1); myTextView2=(TextView)findViewById(R.id.myTextView2);把这两句放在onCreate里面就可以了。