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:

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<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:

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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:

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<EditText
android:id="@+id/editText1"
android:layout\_width="fill\_parent"
android:layout\_height="wrap\_content"
/>

在Activity类中的使用:

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EditText editText1  = (EditText)findViewById(R.id.editText1);

Button的使用方法

布局文件中的配置:

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<Button
android:id="@+id/button1"
android:layout\_width="fill\_parent"
android:layout\_height="wrap\_content"
/>
```xml

**在Activity类中的使用:**

```java
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:

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@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:

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@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:

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<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:

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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

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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:

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<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:

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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

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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:

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

ProgressBar

在布局文件中编写:

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<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:

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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:

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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:

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<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:

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<?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

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public class ActivityTest extends ListActivity {…}

在该类中生成ListView:

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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:

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