初学andriod,工具为studio,就是一个简单的按钮事件,请专家指点:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
myText = (TextView)findViewById(R.id.zrmtextView);
myButton = (Button)findViewById(R.id.zrmbutton);
myButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
myText.setText("你点击了Button");
}
});
}
logcat报错信息:
Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference