Question

如何让我的应用继续检查？意思是继续检查那里是否有文字

String str1, str2;

str1 = word.getText().toString();
str2 = answer.getText().toString();

if(!(str1.equals("")) && !(str2.equals("")))
{
  teach.setEnabled(true);
}
else
{
  teach.setEnabled(false);
}

这是我的java代码，我会把固定的代码，使它检查和每件事？请帮忙！

public class TeachmeDialog extends Activity implements OnClickListener {

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.teachme);
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
    Button teach = (Button)findViewById(R.id.btn_teach_send);
    teach.setOnClickListener(this);


}



@Override
public void onClick(View v) {
    switch(v.getId())
    {
        case R.id.btn_teach_send:
        {
            // Create a new HttpClient and Post Header
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost("http://monaiz.net/get.php");

            String responseStr = "";

            try {
                TextView word = (TextView)findViewById(R.id.tv_teach_request);
                TextView answer = (TextView)findViewById(R.id.tv_teach_response);

                // Add your data
                List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(3);
                nameValuePairs.add(new BasicNameValuePair("word", word.getText().toString()));
                nameValuePairs.add(new BasicNameValuePair("answer", answer.getText().toString()));
                nameValuePairs.add(new BasicNameValuePair("action", "teach"));
                httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

                // Execute HTTP Post Request
                HttpResponse response = httpclient.execute(httppost);
                HttpEntity entity = response.getEntity( );

                responseStr = EntityUtils.toString( entity );

            } catch (Exception e) {
                // TODO Auto-generated catch block
            }

            if( responseStr.equals("ok") )
            {
                Toast.makeText(getApplicationContext(), "Poco just learned a new word!", Toast.LENGTH_LONG).show();
                try {
                    this.finish();
                } catch (Throwable e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}

}

Answer 1

你可以这样做：

String str1, str2;

while (true) 
{
    str1 = word.getText().toString();
    str2 = answer.getText().toString();

    if(!(str1.equals("")) && !(str2.equals("")))
    {
       teach.setEnabled(true);
       break;
    }
    else
    {
       teach.setEnabled(false);
    }
}

这将创建一个循环，它将继续检查某些条件。如果字符串不为空，则会停止使用break关键字。话虽这么说，我不推荐这样的方法，因为它很可能会影响你的用户界面。我建议你做的是将Focus Lost事件附加到文本字段，并在焦点丢失时进行检查。这将允许您仅在需要时运行检查。

Answer 2

请改用TextWatcher。你的“单词”似乎是EditText。所以你可以这样做 -

word.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start, int before,
                int count) {
            // TODO Auto-generated method stub

        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
            // TODO Auto-generated method stub

        }

        @Override
        public void afterTextChanged(Editable s) {
                  teach.setEnabled(true);
            }
    });

Answer 3

在条件中使用 while循环并使用布尔值true ，在其中编写逻辑，在哪里继续检查使用继续关键字，您要停止检查使用中断关键字。

Answer 4

我假设您想在修改EditText的文本时执行某些操作。如果是这样，请使用addTextChangedListener

使用它：

        word.addTextChangedListener(new TextWatcher() {
            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                // do whatever you need to do HERE.
            }
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            }
            @Override
            public void afterTextChanged(Editable s) {
            }
        });

Answer 5

在你的问题中 str1 = word.getText（）。toString（）; str2 = answer.getText（）。toString（）;

表示word或answer是edittext或textview为其编写TextChanged侦听器。

如何在android中持续检查文本更改事件？

5 个答案: