Android中设了4个按钮,却只有一个能用 求大神指点

Question

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.hyyc.warehouse">    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".beginActivity"></activity>
        <activity android:name=".JsonActivity"></activity>
    </application></manifest>package com.hyyc.warehouse;import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;public class MainActivity extends AppCompatActivity {    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button in_But=(Button) findViewById(R.id.In_Button);
        in_But.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                switch (v.getId())
                {
                    case R.id.In_Button:
                        Toast.makeText(MainActivity.this,"YOU CLICK",Toast.LENGTH_SHORT).show();
                        setContentView(R.layout.activity_begin);
                        break;
                    case R.id.new_Button:
                        Toast.makeText(MainActivity.this,"you click",Toast.LENGTH_SHORT).show();
                        setContentView(R.layout.activity_json);
                    default:
                        break;
                }
            }
        });
    }
}
package com.hyyc.warehouse;import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;public class beginActivity extends AppCompatActivity {    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_begin);
        Button begin_But=(Button) findViewById(R.id.begin_Button);
        begin_But.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v1)
            {
                Toast.makeText(beginActivity.this,"YOU CLICK",Toast.LENGTH_SHORT).show();
                Intent intent = new Intent(beginActivity.this,JsonActivity.class);
                startActivity(intent);
            }
        });
    }
}<?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:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.hyyc.warehouse.MainActivity">    <Button
        android:text="入库"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/In_Button"
        android:layout_marginLeft="30dp"
        android:layout_marginTop="30dp"
        />
    <Button
        android:text="开始"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/new_Button"
        android:layout_marginLeft="30dp"
        android:layout_alignBaseline="@+id/In_Button"
        android:layout_alignBottom="@+id/In_Button"
        android:layout_alignParentEnd="true"
        android:layout_marginEnd="59dp" /></RelativeLayout><?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:id="@+id/activity_second"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.hyyc.warehouse.beginActivity">    <Button
        android:text="开始扫描"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/begin_Button"
        android:layout_marginLeft="30dp"
        android:layout_marginTop="30dp"
        /></RelativeLayout>

Answer 1

我猜有用的只有beginActivity里面的那个按钮，别问我为什么！我不想说

Answer 2

Button button = (Button) findViewById(R.id.button_send);
button.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v) {
        // Do something in response to button click
    }
});

Answer 3

in_But.setOnClickListener(new View.OnClickListener()  //这里仅是对一个按钮设置监听事件, 所以下面的switch就没什么卵用了.
        {
            @Override
            public void onClick(View v)
            {
                switch (v.getId())
                {
                    case R.id.In_Button:
                        Toast.makeText(MainActivity.this,"YOU CLICK",Toast.LENGTH_SHORT).show();
                        setContentView(R.layout.activity_begin);
                        break;
                    case R.id.new_Button:
                        Toast.makeText(MainActivity.this,"you click",Toast.LENGTH_SHORT).show();
                        setContentView(R.layout.activity_json);你需要对每个按钮调用.setOnClickListener 来注册监听器, 才会响应点击事件.

Answer 4

public class **Activity extends AppCompatActivity implementsView.OnClickListener {
     /**
     * 界面上的按钮对应方法
     */
    @Override
    public void onClick(View v) {}   private void initialViews() {
        btnXXX = (ImageButton) findViewById(R.id.XXX);
        btnXXX.setOnClickListener(this);
       //有多少写多少
  }
}