“接线”按钮可更改android中的视图

Question

Im building an application that requires when you press the button IE (search) then it opens the search page, click the (home) button then it goes back to the home view. what I'm missing is the knowledge to make that connection between those two views. this is what the home page looks like in XML.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/RelativeLayout1"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
//Title


//Search Student Button 

<Button
    android:id="@+id/button1"
    android:layout_width="86dp"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_centerVertical="true"
    android:longClickable="false"
    android:text="Search Student" />

//New Student Button 

<Button
    android:id="@+id/button2"
    android:layout_width="99dp"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:longClickable="false"
    android:text="New Studetn " />

//Legal Button

<Button
    android:id="@+id/button3"
    android:layout_width="82dp"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_centerVertical="true"
    android:longClickable="false"
    android:text="Legal Info" />

<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="40dp"
    android:layout_above="@+id/button1"
    android:layout_centerHorizontal="true"
    android:layout_marginBottom="66dp"
    android:text="Student Registration "
    android:textAppearance="?android:attr/textAppearanceLarge" />

some pictures of the application. http://imgur.com/aVpqUCZ

Answer 1

Button searchStudentButton;
Button newStudentButton;
Button legalButton;

searchStudentButton = (Button) findViewById(R.id.button1);

searchStudentButton.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View arg0) {
    Intent myIntent = new Intent(CurrentActivity.this, searchStudentActivity.class);
    CurrentActivity.this.startActivity(myIntent);
    }
});

newStudentButton = (Button) findViewById(R.id.button2);

newStudentButton.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View arg0) {
    Intent myIntent = new Intent(CurrentActivity.this, newStudentActivity.class);
    CurrentActivity.this.startActivity(myIntent);
    }
});

legalButton = (Button) findViewById(R.id.button3);

legalButton.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View arg0) {
    Intent myIntent = new Intent(CurrentActivity.this, legalActivity.class);
    CurrentActivity.this.startActivity(myIntent);
    }
});

Don't forget to add your new activity in the AndroidManifest.xml:

<activity android:label="@string/app_name" android:name="searchStudentActivity"/>
<activity android:label="@string/app_name" android:name="newStudentActivity"/>
<activity android:label="@string/app_name" android:name="legalActivity"/>

Answer 2

When dealing with multiple views and/or buttons like you are, I usually prefer using only one instance of onClickListener for all the views, to keep the code cleaner.

public class MainActivity extends Activity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.my_layout);

        Button btnSearchStudent = (Button) findViewById(R.id.button1);
        Button btnNewStudent = (Button) findViewById(R.id.button2);
        Button btnLegalInfo = (Button) findViewById(R.id.button3);

        btnSearchStudent.setOnClickListener(this);
        btnNewStudent.setOnClickListener(this);
        btnLegalInfo.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.button1: {
                Intent intent = new Intent(this, SearchStudentActivity.class);
                startActivity(intent);
                break;
            }
            case R.id.button2: {
                Intent intent = new Intent(this, NewStudentActivity.class);
                startActivity(intent);
                break;
            }
            case R.id.button3: {
                Intent intent = new Intent(this, LegalInfoActivity.class);
                startActivity(intent);
                break;
            }
        }
    }
}

I would recommend that you change the android:id attribute of your buttons to a more meaningful name. This makes it easier to see what you're referencing in the code. I personally prefer prepending my views with an abreviation of the view class such as btn_ for Button and tv_ for TextView . Remember to update your calls to findViewById() and the id's used in the switch statement.

Finally, don't forget to add your activities to the AndroidManifest.xml file as Sagar Pilkhwal posted, if you haven't already.