主要活动包含微调器和按钮。 MainActivity.java代码如下。
public class MainActivity extends AppCompatActivity implements LoadNew.VCallback {
public Spinner dropdown;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dropdown = (Spinner) findViewById(R.id.spinner1);
//Create a list of items for the spinner.
String[] items = new String[]{"select topic", "topic1", "topic2"};
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, items);
dropdown.setAdapter(adapter);
dropdown.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
// TODO Auto-generated method stub
String sp1 = String.valueOf(dropdown.getSelectedItem());
if (sp1.contentEquals("select topic")) {
loadFun("");
}
if (sp1.contentEquals("topic1")) {
loadFun("topic1");
}
if (sp1.contentEquals("topic2")) {
loadFun("topic2");
}
}
@Override
public void onNothingSelected(AdapterView<?> parentView){
// TODO Auto-generated method stub
}
});
Button x = (Button) findViewById(R.id.full_screen);
x.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
loadFun("topic2", 0);
}
});
}
public void loadFun(String topicName, int i) {
LoadNew st = new LoadNew(this);
st.display(topicName, i);
}
}
主要活动的xml布局如下(activity_main.xml)。
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<Spinner
android:id="@+id/spinner1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@android:drawable/btn_dropdown"
android:spinnerMode="dropdown" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<Button
android:id="@+id/full_screen"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Full Screen"
style="?android:attr/borderlessButtonStyle"/>
</LinearLayout>
<LinearLayout
android:id="@+id/full_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
</LinearLayout>
</LinearLayout>
</RelativeLayout>
还有另一个java类LoadNew.java如下。
public class LoadNew {
public interface VCallback {
//To access methods of MainActivity class
}
public Activity activity;
public LoadNew(Activity _activity) {
this.activity = _activity;
VCallback callerActivity = (VCallback) activity;
}
//Display PDF
public void display(String topicName, int i) {
LinearLayout fullScreen = (LinearLayout) this.activity.findViewById(R.id.full_view);
fullScreen.removeAllViews();//Clear field
LayoutInflater inflater = (LayoutInflater) this.activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View view = inflater.inflate(R.layout.activity_load, null);
if(i ==0) {
this.activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
this.activity.setContentView(view);
}
TextView tv= (TextView) this.activity.findViewById(R.id.tv1);
tv.setText(topicName);
tv.setTextSize(100);
}
}
activity_load.xml文件如下。
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout> xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:id="@+id/tv1"
android:layout_below="@+id/bar"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</RelativeLayout>
在微调器中选择某个项目时,相应的文本将显示在textview中。按下按钮后,textview将以全屏模式显示。 现在我想返回上一个视图(通过按下后退按钮或屏幕上的单个选项卡),即单击按钮之前的视图。我怎样才能做到这一点?提前感谢您的耐心和帮助。
答案 0 :(得分:0)
最简单的方法是在一个活动上安装微调器和非全屏TextView,并在按钮点击时使用全屏模式打开第二个活动。