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Java中点击事件的四种写法

2017-05-18 09:54 232 查看

点击事件的必备条件：实现
OnClickListener
接口，重写
v)
方法以拨号简单案例为例，如下图效果：

逻辑流程：获取点击对象，获取数据

给对象设置监听类

实现

OnClickListener

接口,重写

onClick(Viewv)

方法

onClick(Viewv)

逻辑：获取输入内容：使用

EditText

对象的

getText()

方法，该方法返回值为

Editable

，需要用

toString()

转换成

String

类型
判断输入是否为空，

TextUtils.isEmpty(str)

方法判断字符串

str

是否为空
为空则提示

号码不能为空

，使用

Toast.makeText(MainActivity.this, "号码不能为空", Toast.LENGTH_SHORT).show();

Toast makeText (Context context, CharSequence text, int duration)

返回值为Toast，参数列表（Context对象，提示内容，显示时长）
如果不为空，

new

一个

Intent

对象，使用

Intent

对象的

setAction(String action)

方法设置动作，使用

Intent

对象的

setData(Uri uriData)

方法设置数据。

startActivity(Intent intent)

方法启动Activity。

注：应该在程序清单文件AndroidManifest.xml中添加

<uses-permission android:name="android.permission.CALL_PHONE"/>

，拨打电话时，美国紧急电话不会直接拨打三种方法：第四种不推荐，前三种酌情使用

1. 内部实现类

布局文件：activity_main.xml

<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"    tools:context="${relativePackage}.${activityClass}" >

<EditText        android:id="@+id/editText1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:focusable="true"        android:focusableInTouchMode="true"        android:hint="在此输入电话号码">

</EditText>

<Button        android:id="@+id/button1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_below="@+id/editText1"        android:layout_marginTop="14dp"        android:text="拨打此号码" />

<Button        android:id="@+id/button2"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentLeft="true"        android:layout_below="@+id/button1"        android:text="Button2" />

<Button        android:id="@+id/button3"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentLeft="true"        android:layout_below="@+id/button2"        android:text="Button3" /></RelativeLayout>

MainActivity.java

    package com.example.onclick1;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.storage.OnObbStateChangeListener;
import android.text.TextUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {        private EditText editText;        @Override
protected void onCreate(Bundle savedInstanceState) {            super.onCreate(savedInstanceState);            setContentView(R.layout.activity_main);
editText = (EditText) findViewById(R.id.editText1);
Button button1 = (Button) findViewById(R.id.button1);
Button button2 = (Button) findViewById(R.id.button2);
Button button3 = (Button) findViewById(R.id.button3);            //设置监听类
button1.setOnClickListener(new MyOnClickListener());
button2.setOnClickListener(new MyOnClickListener());
button3.setOnClickListener(new MyOnClickListener());
}        private class MyOnClickListener implements OnClickListener{            @Override
public void onClick(Viewv) {                int i = v.getId();                switch (i) {                case R.id.button1:
String number = editText.getText().toString();                    if (TextUtils.isEmpty(number)) {
Toast.makeText(MainActivity.this, "号码不能为空", Toast.LENGTH_SHORT).show();
}else {
Intent intent = new Intent();
intent.setAction(intent.ACTION_CALL);
Uri data = Uri.parse("tel:"+number);
intent.setData(data);                        startActivity(intent);
}                    break;                case R.id.button2:
Toast.makeText(MainActivity.this, "你点击了Button2", Toast.LENGTH_SHORT).show();                    break;                case R.id.button3:
Toast.makeText(MainActivity.this, "你点击了Button3", Toast.LENGTH_SHORT).show();                    break;
}
}

}
}

2. 内部匿名类

MainActivity.java

    package com.example.onclick1;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.storage.OnObbStateChangeListener;
import android.text.TextUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {        private EditText editText;        @Override
protected void onCreate(Bundle savedInstanceState) {            super.onCreate(savedInstanceState);            setContentView(R.layout.activity_main);
editText = (EditText) findViewById(R.id.editText1);
Button button1 = (Button) findViewById(R.id.button1);
Button button2 = (Button) findViewById(R.id.button2);
Button button3 = (Button) findViewById(R.id.button3);            //设置监听类
button1.setOnClickListener(new OnClickListener() {                @Override
public void onClick(Viewv) {
String number = editText.getText().toString();                    if(TextUtils.isEmpty(number)){
Toast.makeText(MainActivity.this, "[内部匿名类]号码不能为空", Toast.LENGTH_SHORT).show();
}else{
Intent intent = new Intent();
intent.setAction(intent.ACTION_CALL);
intent.setData(Uri.parse("tel:"+number));                        startActivity(intent);
}
}
});
button2.setOnClickListener(new OnClickListener() {                @Override
public void onClick(Viewv) {
Toast.makeText(MainActivity.this, "[内部匿名类]你点击了Button2", Toast.LENGTH_SHORT).show();
}
});
button3.setOnClickListener(new OnClickListener() {                @Override
public void onClick(Viewv) {
Toast.makeText(MainActivity.this, "[内部匿名类]你又点击了button3", Toast.LENGTH_SHORT).show();

}
});
}
}

3. Activity实现OnClickLitener

MainActivity.java

    package com.example.onclick1;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.storage.OnObbStateChangeListener;
import android.text.TextUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener{        private EditText editText;        @Override
protected void onCreate(Bundle savedInstanceState) {            super.onCreate(savedInstanceState);            setContentView(R.layout.activity_main);
editText = (EditText) findViewById(R.id.editText1);
Button button1 = (Button) findViewById(R.id.button1);
Button button2 = (Button) findViewById(R.id.button2);
Button button3 = (Button) findViewById(R.id.button3);            //设置监听类
button1.setOnClickListener(this);
button2.setOnClickListener(this);
button3.setOnClickListener(this);
}        @Override
public void onClick(Viewv) {            int id = v.getId();            switch (id) {            case R.id.button1:
String number = editText.getText().toString();                if (TextUtils.isEmpty(number)) {
Toast.makeText(this, "[Activity实现类]号码不能为空", Toast.LENGTH_SHORT).show();
}else {
Intent intent = new Intent();
intent.setAction(intent.ACTION_CALL);
intent.setData(Uri.parse("tel:"+number));                    startActivity(intent);
}                break;            case R.id.button2:
Toast.makeText(this, "[Activity实现类]你点击了Button2", Toast.LENGTH_SHORT).show();                break;            case R.id.button3:
Toast.makeText(this, "[Activity实现类]你点击了Button3", Toast.LENGTH_SHORT).show();                break;
}
}
}

4. 结合layout文件声明方法

activity_main.xml

<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"        tools:context="${relativePackage}.${activityClass}" >

<EditText            android:id="@+id/editText1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:focusable="true"            android:focusableInTouchMode="true"            android:hint="在此输入电话号码">

</EditText>

<Button            android:id="@+id/button1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_below="@+id/editText1"            android:layout_marginTop="14dp"            android:onClick="button"            android:text="拨打此号码" />

<Button            android:id="@+id/button2"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_alignParentLeft="true"            android:layout_below="@+id/button1"            android:onClick="button"            android:text="Button2" />

<Button            android:id="@+id/button3"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_alignParentLeft="true"            android:layout_below="@+id/button2"            android:onClick="button"            android:text="Button3" />

</RelativeLayout>

MainActivity.java

    package com.example.onclick1;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.storage.OnObbStateChangeListener;
import android.text.TextUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity{        @Override
protected void onCreate(Bundle savedInstanceState) {            super.onCreate(savedInstanceState);            setContentView(R.layout.activity_main);
}        public void button(Viewv) {
EditText editText = (EditText) findViewById(R.id.editText1);            switch (v.getId()) {            case R.id.button1:
String number = editText.getText().toString();                if (TextUtils.isEmpty(number)) {
Toast.makeText(this, "[布局文件中Button的android:onClick属性]号码不能为空", Toast.LENGTH_SHORT).show();
}else {
Intent intent = new Intent();
intent.setAction(intent.ACTION_CALL);
intent.setData(Uri.parse("tel:"+number));                    startActivity(intent);
}                break;            case R.id.button2:
Toast.makeText(this, "[布局文件中Button的android:onClick属性]你点击了Button2", Toast.LENGTH_SHORT).show();                break;            case R.id.button3:
Toast.makeText(this, "[布局文件中Button的android:onClick属性]你点击了Button3", Toast.LENGTH_SHORT).show();                break;
}
}
}

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标签： Java 接口字符串

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