[Android]Java中點擊事件的四種寫法

點擊事件的必備條件：實現介面，重寫方法以撥號簡單案例為例，如下圖效果：邏輯流程： 1. 獲取點擊對象，獲取數據 2. 給對象設置監聽類 3. 實現介面,重寫方法邏輯： 1. 獲取輸入內容：使用對象的方法，該方法返回值為，需要用轉換成類型 2. 判斷輸入是否為空，方法判斷字元 ...

點擊事件的必備條件：實現OnClickListener介面，重寫onclick(View v)方法

以撥號簡單案例為例，如下圖效果：
演示圖片

邏輯流程：

獲取點擊對象，獲取數據

給對象設置監聽類

實現OnClickListener介面,重寫onClick(View v)方法

onClick(View v)邏輯：

獲取輸入內容：使用EditText對象的getText()方法，該方法返回值為Editable，需要用toString()轉換成String類型

判斷輸入是否為空，TextUtils.isEmpty(str)方法判斷字元串str是否為空

為空則提示號碼不能為空，使用Toast.makeText(MainActivity.this, "號碼不能為空", Toast.LENGTH_SHORT).show();,
Toast makeText (Context context, CharSequence text, int duration)返回值為Toast，參數列表（Context對象，提示內容，顯示時長）

如果不為空，new一個Intent對象，使用Intent對象的setAction(String action)方法設置動作，使用Intent對象的setData(Uri uriData)方法設置數據。startActivity(Intent intent)方法啟動Activity。

註：應該在程式清單文件AndroidManifest.xml中添加<uses-permission android:name="android.permission.CALL_PHONE"/>，撥打電話時，美國緊急電話不會直接撥打

三種方法：第四種不推薦，前三種酌情使用

1. 內部實現類

佈局文件：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="在此輸入電話號碼">

    </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="撥打此號碼" />

    <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);

            //設置監聽類
            button1.setOnClickListener(new MyOnClickListener());
            button2.setOnClickListener(new MyOnClickListener());
            button3.setOnClickListener(new MyOnClickListener());
        }
        private class MyOnClickListener implements OnClickListener{

            @Override
            public void onClick(View v) {
                int i = v.getId();
                switch (i) {
                case R.id.button1:
                    String number = editText.getText().toString();
                    if (TextUtils.isEmpty(number)) {
                        Toast.makeText(MainActivity.this, "號碼不能為空", 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, "你點擊了Button2", Toast.LENGTH_SHORT).show();
                    break;
                case R.id.button3:
                    Toast.makeText(MainActivity.this, "你點擊了Button3", Toast.LENGTH_SHORT).show();
                    break;
                }
            }

        }
    }

2. 內部匿名類

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);

            //設置監聽類
            button1.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    String number = editText.getText().toString();
                    if(TextUtils.isEmpty(number)){
                        Toast.makeText(MainActivity.this, "[內部匿名類]號碼不能為空", 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(View v) {
                    Toast.makeText(MainActivity.this, "[內部匿名類]你點擊了Button2", Toast.LENGTH_SHORT).show();
                }
            });
            button3.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    Toast.makeText(MainActivity.this, "[內部匿名類]你又點擊了button3", Toast.LENGTH_SHORT).show();

                }
            });
        }
    }

3. Activity實現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);

            //設置監聽類
            button1.setOnClickListener(this);
            button2.setOnClickListener(this);
            button3.setOnClickListener(this);
        }
        @Override
        public void onClick(View v) {
            int id = v.getId();
            switch (id) {
            case R.id.button1:
                String number = editText.getText().toString();
                if (TextUtils.isEmpty(number)) {
                    Toast.makeText(this, "[Activity實現類]號碼不能為空", 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實現類]你點擊了Button2", Toast.LENGTH_SHORT).show();
                break;
            case R.id.button3:
                Toast.makeText(this, "[Activity實現類]你點擊了Button3", Toast.LENGTH_SHORT).show();
                break;
            }
        }
    }

4. 結合layout文件聲明方法

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="在此輸入電話號碼">

        </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="撥打此號碼" />

        <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(View v) {
        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, "[佈局文件中Button的android:onClick屬性]號碼不能為空", 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, "[佈局文件中Button的android:onClick屬性]你點擊了Button2", Toast.LENGTH_SHORT).show();
                break;
            case R.id.button3:
                Toast.makeText(this, "[佈局文件中Button的android:onClick屬性]你點擊了Button3", Toast.LENGTH_SHORT).show();
                break;
            }
        }
    }