EditText内容清空java.lang.IllegalStateException

Java codepackage android_edittext.ycf.test;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class Android_edittextActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button btn1 = (Button) this.findViewById(R.id.button1);
        btn1.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                EditText et = (EditText) Android_edittextActivity.this
                        .findViewById(R.id.edit_2);
                String ettext = et.getText().toString();
                if(ettext.length() <= 5)
                {
                    Toast.makeText(Android_edittextActivity.this, "注册密码太短，注册失败",
                            R.id.button1).show();
                    et.setText("");//*******DDMS提示问题出现在这行和下面一行
                    Android_edittextActivity.this.setContentView(et);
                }
                else
                {
                    Toast.makeText(Android_edittextActivity.this, "恭喜您注册成功",
                            R.id.button1).show();
                }               
            }
        });
        Button btn2 = (Button) this.findViewById(R.id.button2);
        btn2.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                EditText et1 = (EditText) Android_edittextActivity.this
                        .findViewById(R.id.edit_1);
                et1.setText("");
                Android_edittextActivity.this.setContentView(et1);
                EditText et2 = (EditText) Android_edittextActivity.this
                        .findViewById(R.id.edit_2);
                et1.setText("");
                Android_edittextActivity.this.setContentView(et2);
            }
        });
    }
}

菜鸟问题，做了一个界面，两个editview，一个是姓名一个是密码，如果密码长度太短进行提示，并且清空，可是清空的这两行代码DDMS总是提示错误，错误类型为java.lang.IllegalStateException

请问这样写是不对的么

Android_edittextActivity.this.setContentView(et2);
Android_edittextActivity.this.setContentView(et);

想请问这2行是做什么用的？

注掉吧

EditText et2 = (EditText) Android_edittextActivity.this
  .findViewById(R.id.edit_2);
EditText et1 = (EditText) Android_edittextActivity.this
  .findViewById(R.id.edit_1);

这些代码放在oncreate里边去吧。

呃，不能在onClick这样的监听函数中改变界面的显示，但可以这样写
先在类中声明：
Handler mHandler = new Handler();
Runnable mRunnable = new Runnable() {

@Override
public void run() {
mEdit.setText("");
}};

onClick中，这样调用mHandler.post(mRunnable);

这样就没问题了