Java android xml文本框没有文本=没有按钮点击

Question

我这里有个问题。 我需要它，所以如果我的两个文本框中没有任何文本，您将无法点击按钮

我的JAVA代码:

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(), "Poka just learned a new word!", Toast.LENGTH_LONG).show();
                try {
                    this.finish();
                } catch (Throwable e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}
}

然后这是我的 xml 代码，它是应用程序设计的 obv..

按钮和编辑文本内容就在那里

 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"  >

    <ScrollView android:scrollbars="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:fillViewport="true" android:isScrollContainer="true">
        <LinearLayout android:orientation="vertical" android:id="@+id/ll_teach" android:background="#ffffffff" android:layout_width="fill_parent" android:layout_height="fill_parent">
            <LinearLayout android:gravity="center_horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_marginTop="10.0dip" android:layout_marginBottom="2.0dip" android:layout_weight="0.0">
                <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginRight="50.0dip" android:src="@drawable/if_ask" />
            </LinearLayout>
            <LinearLayout android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_weight="1.0">

                    <EditText android:gravity="top|left|center" android:maxLength="30" android:id="@+id/tv_teach_request" android:background="@drawable/mespeak" android:paddingLeft="23.0dip" android:paddingTop="6.0dip" android:paddingRight="28.0dip" android:paddingBottom="23.0dip" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_marginLeft="20.0dip" android:layout_marginRight="5.0dip" android:layout_alignParentTop="true" style="@style/TeachBubbleFont" />

            </LinearLayout>
            <LinearLayout android:gravity="center_horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_marginTop="10.0dip" android:layout_marginBottom="2.0dip" android:layout_weight="0.0">
                <ImageView android:layout_gravity="left" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginRight="40.0dip" android:src="@drawable/then_response" />
            </LinearLayout>
            <LinearLayout android:layout_gravity="center" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1.0">
                    <EditText android:gravity="top|left|center" android:maxLength="30" android:id="@+id/tv_teach_response" android:background="@drawable/pokaspeak" android:paddingLeft="28.0dip" android:paddingTop="6.0dip" android:paddingRight="23.0dip" android:paddingBottom="23.0dip" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_marginLeft="1.0dip" android:layout_marginRight="20.0dip" android:layout_alignParentTop="true" android:layout_alignParentRight="true" style="@style/TeachBubbleFont" />
            </LinearLayout>
            <RelativeLayout android:gravity="center_vertical" android:id="@+id/RelativeLayoutBtn" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="0.0">
                <Button android:id="@+id/btn_teach_send" android:layout_width="wrap_content" android:layout_height="35.0dip" android:text="@string/btn_teach_send" android:layout_centerInParent="true" />
            </RelativeLayout>
        </LinearLayout>
    </ScrollView>

</LinearLayout>

Answer 1

您只需为此设置按钮的enabled 属性。如果两个文本框没有文本，则禁用按钮，如果有文本，则启用按钮。

这里是例子

String str1, str2;

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

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

编辑

如果您想在任何编辑文本发生更改时立即进行检查，那么您需要使用 textchangelistner。

这里我为它做了一个小例子。仅当 2 个 edittext 包含任何文本时才启用按钮。 希望这会对您有所帮助。

public class TSActivity extends Activity {

     String str = "";
     String str1 = "";
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        final Button btn = (Button)findViewById(R.id.btn);
        TextView txt = (TextView)findViewById(R.id.text);
        TextView txt1 = (TextView)findViewById(R.id.text1);
        btn.setEnabled(false);


        txt.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) {
                // TODO Auto-generated method stub

                str = s.toString();
                if( !(str.equals("")) && !(str1.equals("")) )
                {
                    btn.setEnabled(true);
                }
                else
                {
                    btn.setEnabled(false);
                }
            }
        });
 /**************************************************************************************************/       
        txt1.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) {
                // TODO Auto-generated method stub

                str1 = s.toString();
                if( !(str.equals("")) && !(str1.equals("")) )
                {
                    btn.setEnabled(true);
                }
                else
                {
                    btn.setEnabled(false);
                }
            }
        });
    }  
}

谢谢...