Android中的常用控件及其基本用法

TextView的使用方法


布局文件中的配置:

<TextView  
    android:id="@+id/textView1"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/arthinking"
/>


在Activity类中的使用:

TextView textView1 = (TextView)findViewById(R.id.textView1);
textView1.setText(R.string.username);
EditText的使用方法


布局文件中的配置:

<EditText 
    android:id="@+id/editText1"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
	/>


在Activity类中的使用:

EditText editText1  = (EditText)findViewById(R.id.editText1);
Button的使用方法


布局文件中的配置:

<Button
    android:id="@+id/button1"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
	/>


在Activity类中的使用:

Button button1 = (Button)findViewById(R.id. button1);
//TestListener为继承OnClickListener的类
button1.setOnClickListener(new TestListener());
Menu的使用方法

onCreateOptionsMenu(Menu menu)
Initialize the contents of the Activity’s standard options menu.

onCreateOptionsMenu是Activity中的一个方法,当用户点击了MENU按钮时,Activity会触发该方法,Menu的创建在这里执行:

@Override
public boolean onCreateOptionsMenu(Menu menu) {
	menu.add(0, 1, 1, R.string.back);
	menu.add(0,2,2,R.string.exit);
	return super.onCreateOptionsMenu(menu);
}


为按钮添加方法,需要实现Activity的onOptionsItemSelected方法:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
	if(item.getItemId() == 2){
		finish();
	}
	return super.onOptionsItemSelected(item);
}
RadioGroup和RadioButton


布局文件的编写:

<RadioGroup
    android:id="@+id/radioGroup1"
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:orientation="vertical"
    >
    <RadioButton
    	    android:id="@+id/radioButton1"
 	    android:layout_width="wrap_content" 
  	    android:layout_height="wrap_content" 
  	    android:text="@string/female"
  	    />
    <RadioButton
    	    android:id="@+id/radioButton2"
 	    android:layout_width="wrap_content" 
  	    android:layout_height="wrap_content" 
  	    android:text="@string/male"
  	    />
</RadioGroup>


在Activity中使用:

RadioGroup radioGroup1 = (RadioGroup)findViewById(R.id.radioGroup1);
RadioButton radioButton1 = (RadioButton)findViewById(R.id.femaleButton);
RadioButton radioButton2 = (RadioButton)findViewById(R.id. radioButton2);


为RadioGroup设置监听器,使用RadioGroup.OnCheckedChangeListener类

radioGroup1.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {

	@Override
	public void onCheckedChanged(RadioGroup group, int checkedId) {
		if(radioButton1.getId() == checkedId){
			System.out.println("radioButton1");
		}
		else if(radioButton2.getId() == checkedId)
		{
			System.out.println("radioButton2");
		}
	}
});
CheckBox


布局文件的编写:

<CheckBox
	android:id="@+id/checkBox1"
 	android:layout_width="wrap_content" 
  	android:layout_height="wrap_content" 
  	android:text="@string/checkBox1"
  	/>
<CheckBox
	android:id="@+id/checkBox2"
 	android:layout_width="wrap_content" 
  	android:layout_height="wrap_content" 
  	android:text="@string/checkBox2"
  	/>


在Activity中的使用:

CheckBox checkBox1 = (CheckBox)findViewById(R.id.checkBox1);
CheckBox checkBox2 = (CheckBox)findViewById(R.id.checkBox2);


为多选按钮添加监听器,这里使用CompoundButton.OnCheckedChangeListener

checkBox1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

	@Override
	public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
		if(isChecked)
		{
			System.out.println("checkBox1 is checked");
		}
		else
		{
			System.out.println("checkBox1 is unchecked");
		}
	}
});
checkBox2.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

	@Override
	public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
		// TODO Auto-generated method stub
		if(isChecked)
		{
			System.out.println("checkBox2 is checked");
		}
		else
		{
			System.out.println("checkBox2 is unchecked");
		}
	}
});
Toast

public class
Toast
extends Object

A toast is a view containing a quick little message for the user. The toast class helps you create and show those.


直接在Activity中使用:

Toast.makeText(RadioTest.this, "checkBox1", Toast.LENGTH_SHORT).show();
ProgressBar


在布局文件中编写:

<ProgressBar
	android:id="@+id/progressBar1"
	style="?android:attr/progressBarStyleHorizontal"
	android:layout_width="200dp"
	android:layout_height="wrap_content"
	android:visibility="gone"
	/>


在Activity中使用:

ProgressBar progressBar1 = (ProgressBar)findViewById(R.id.progressBar1);


这里使用一个鼠标点击事件触发处理该进度条:

private int i = 0;
class ButtonListener implements OnClickListener{

	@Override
	public void onClick(View v) {
		if(i == 0) {
			progressBar1.setVisibility(View.VISIBLE);
			progressBar1.setMax(100);
		}
		else if ( i < progressBar1.getMax()){
			progressBar1.setProgress(i);
			progressBar1.setSecondaryProgress(i + 10);
		}
		else{
			progressBar1.setVisibility(View.GONE);
		}
		i = i + 10 ;
	}	
}
ListView

public class
ListView
extends AbsListView

A view that shows items in a vertically scrolling list. The items come from the ListAdapter associated with this view.

要使用ListView必须继承ListActivity类,同时需要在代码中构造 一个android.widget.SimpleAdapter类,用于辅助创建ListView。除此之外还需要创建另外一个布局文件供ListView使用:


主布局文件的编写:

<ListView android:id="@id/android:list" android:layout_width="fill_parent"
	android:layout_height="wrap_content" android:drawSelectorOnTop="true"
	android:scrollbars="vertical" />


另外需要一个布局文件供ListView使用:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="fill_parent" android:layout_height="fill_parent"
	android:orientation="horizontal" android:paddingLeft="10dip"
	android:paddingRight="10dip" android:paddingTop="2dip"
	android:paddingBottom="2dip">
	<TextView android:id="@+id/user_name" android:layout_width="180dip"
		android:layout_height="30dip" android:textSize="5pt"
		android:singleLine="true" />
	<TextView android:id="@+id/user_id" android:layout_width="fill_parent"
		android:layout_height="fill_parent" android:gravity="right"
		android:textSize="5pt" />
</LinearLayout>


继承ListActivity的类

public class ActivityTest extends ListActivity {…}


在该类中生成ListView:

setContentView(R.layout.main);
ArrayList<HashMap<String, String>> list = new ArrayList<HashMap<String, String>>();
HashMap<String, String> map1 = new HashMap<String, String>();
HashMap<String, String> map2 = new HashMap<String, String>();
HashMap<String, String> map3 = new HashMap<String, String>();
map1.put("user_name", "arthinking");
map1.put("user_id", "001");
map2.put("user_name", "Jason");
map2.put("user_id", "002");
list.add(map1);
list.add(map2);
SimpleAdapter listAdapter = new SimpleAdapter(this, list,
		R.layout.user, new String[]{"user_name","user_id"},
		new int[]{R.id.user_name,R.id.user_id});
setListAdapter(listAdapter);


要实现监听事件,可以实现ListActivity的onListItemClick方法:

@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
	super.onListItemClick(l, v, position, id);
	System.out.println(id);

}

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