android - 如何清除 Android TextView 中的文本？

Question

所以我有一个像这样的 Android 程序:

package com.example.androiddemo;

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

public class AndroidDemo extends Activity {
    String[] messages = {"Short Text",
                         "I want to show some really long text" +
                         "on the display of the phone. " +
                         "Having run out of ideas on what to type, " +
                         "I am adding this text which makes absolutely " +
                         "no sense."};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        final Button add = (Button) findViewById(R.id.addBtn);
        final Button clear = (Button) findViewById(R.id.clrBtn);
        final EditText text = (EditText) findViewById(R.id.display);

        add.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(v == add){
                    text.setText(messages[new java.util.Random().nextInt(messages.length)]);
                }else if(v == clear){
                    text.setText("");
                }
            }
        });
    }
}  

将文本添加到 TextView 的按钮工作得很好，但文本永远不会清除。
我认为 TextView 的操作类似于将文本设置为 "" 的 JTextField 或 JTextArea清除它。

如何清除文本？

Answer 1

试试这个，

public class AndroidDemo extends Activity implements OnClickListener{
Button add, clear;
EditText text;
@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        add = (Button) findViewById(R.id.addBtn);
        clear = (Button) findViewById(R.id.clrBtn);
        text = (EditText) findViewById(R.id.display);
        add.setOnClickListener(this);
        clear.setOnClickListener(this);
        }
@Override
public void onClick(View v){
    if(v == add){
        text.setText(messages[new java.util.Random().nextInt(messages.length)]);
    }else if(v == clear){
        text.setText("");
    }
    }
  }