android 入门

[xiyang865]

菜鸟入门问题，请问各位大侠代码哪里出了问题，想实现在editTex 中输入相关文字，在textview里面显示出来。运行结果是程序出错。


package may.mine.android.testedittext;

import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.TextView.OnEditorActionListener;

public class TestEditTextActivity extends Activity {
/** Called when the activity is first created. */
private TextView tv;
private EditText et;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
tv.findViewById(R.id.textview1);
et.findViewById(R.id.editText1);
//tv.setTextSize(30);

et.setHint("请输入数字");
et.setOnEditorActionListener(new OnEditorActionListener () {

@Override
public boolean onEditorAction(TextView v, int actionId,
KeyEvent event) {
// TODO Auto-generated method stub
tv.setText("文本框输入的数字是："+et.getText().toString());
return false;
}

});
}
}

[AMinfo]

代码写得够简的，不能太省

tv.findViewById(R.id.textview1);
et.findViewById(R.id.editText1);

改为

tv = (TextView) findViewById(R.id.textview1);
et = (EditText) findViewById(R.id.editText1);