Question

我想创建一个必须具有edittexts和两个按钮ok和cancel的活动，其中ok按钮应该首先被禁用，并且应该在验证用户名和密码时启用。我的代码是 -

public class DisableButton extends Activity {
EditText et1,et2;
Button b1,b2;
String et_value, pwd_value;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_disable_button);
    et1=(EditText)findViewById(R.id.editText1);
    et2=(EditText)findViewById(R.id.editText2);
    b1=(Button)findViewById(R.id.button1);
    b1.setEnabled(false);
    b2=(Button)findViewById(R.id.button2);
    et_value=et1.getText().toString();
    pwd_value=et2.getText().toString();

    if((et_value=="pbpathi")&&(pwd_value=="1234"))
    {
        b1.setEnabled(true);
    }

}
public void okClick(View v){
    Toast.makeText(getBaseContext(), "Username is "+et_value+" \n password is
"+pwd_value, Toast.LENGTH_LONG).show();

}

public void cancelClick(View v){

}

}

我的xml文件是 -

 <LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:gravity="center"
 android:orientation="vertical"
 tools:context="com.example.labs.DisableButton" >

<EditText
    android:id="@+id/editText1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:ems="10" />


<EditText
    android:id="@+id/editText2"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:ems="10"
    android:inputType="textPassword" />


<Button
    android:id="@+id/button1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:text="OK" 
    android:onClick="okClick"/>

<Button
    android:id="@+id/button2"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:text="Cancel"
    android:onClick="cancelClick" />

</LinearLayout>

Answer 1

首先，

你不应该获取edittexts＆＃39; onCreate中的值，但onClick

中的值

其次，

您不应该使用==来比较字符串。它会比较对象。

因此请将代码更改为：

public void okClick(View v){
    Toast.makeText(getBaseContext(), "Username is "+et_value+" \n password is
"+pwd_value, Toast.LENGTH_LONG).show();
    et_value=et1.getText().toString();
    pwd_value=et2.getText().toString();

    // You can use equalsIgnoreCase for cas insensitive comparison
    if((et_value.equals("pbpathi"))&&(pwd_value.equals("1234"))) 
    {
        b1.setEnabled(true);
    }
}

希望得到这个帮助。

Answer 2

if((et_value.equals("pbpathi")&&(pwd_value.equals("1234")))
{
    b1.setEnabled(true);
}

equal mathed in java

Answer 3

使用equals代替==。

if("pbpathi".equals(et_value) && "1234".equals(pwd_value)) {
    ....
}

Answer 4

public class DisableButton extends Activity {
    EditText et1, et2;
    Button b1, b2;
    String et_value, pwd_value;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        et1 = (EditText) findViewById(R.id.editText1);
        et2 = (EditText) findViewById(R.id.editText2);
        b1 = (Button) findViewById(R.id.button1);
        b1.setEnabled(false);`enter code here`
        b2 = (Button) findViewById(R.id.button2);

        et1.addTextChangedListener(mTextWatcher);
        et2.addTextChangedListener(mTextWatcher);

    }

    public void okClick(View v) {
        et_value = et1.getText().toString();
        pwd_value = et2.getText().toString();

        Toast.makeText(getBaseContext(),
                "Username is " + et_value + " \n password is" + pwd_value,
                Toast.LENGTH_LONG).show();

    }

    public void cancelClick(View v) {

    }

    private final TextWatcher mTextWatcher = new TextWatcher() {

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {


        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before,
                int count) {


        }

        @Override
        public void afterTextChanged(Editable s) {
            if ((et1.getText().toString().equals("pbpathi"))
                    && (et2.getText().toString().equals("1234"))) {
                b1.setEnabled(true);



            }

        }
    };

}

为什么我无法在android中启用按钮

4 个答案: