Question

我起诉Android Studio 1.5.1 android api 23。当我单击计算按钮时，它不会触发public void onClick(View v)功能。

以下是MainActivity.java：

                package gradescalculator.com.calculator.gradescalculator;

            import android.app.AlertDialog;
            import android.content.DialogInterface;
            import android.content.Intent;
            import android.os.Bundle;
            import android.support.design.widget.FloatingActionButton;
            import android.support.design.widget.Snackbar;
            import android.support.v7.app.AppCompatActivity;
            import android.support.v7.widget.Toolbar;
            import android.view.Menu;
            import android.view.MenuItem;
            import android.view.View;
            import android.widget.EditText;

            public class MainActivity extends AppCompatActivity implements View.OnClickListener{

                EditText answer1;
                EditText answer2;
                EditText answer3;
                private View calculate;
                @Override
                protected void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.activity_main);
                Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
                   // calculate = () findViewById(R.id.calculate);
                calculate = findViewById(R.id.calculate);
                calculate.setOnClickListener(this);


                /*
                calculate.setOnClickListener(new View.OnClickListener() {
                    public void onClick(View v) {
                    answer1 = (EditText) findViewById(R.id.answer1);
                    answer2 = (EditText) findViewById(R.id.answer2);
                    answer3 = (EditText) findViewById(R.id.answer3);
                    String answer1Value = answer1.getText().toString();
                    String answer2Value = answer2.getText().toString();
                    String answer3Value = answer3.getText().toString();

                    Float answer1ValueFloat = new Float(answer1Value);

                    Float answer2ValueFloat = new Float(answer2Value);

                    Float answer3ValueFloat = new Float(answer3Value);
                    Float average = (answer1ValueFloat+answer2ValueFloat+answer3ValueFloat )/3;
                    Intent i = AnswerActivity.newIntent(MainActivity.this,average);
                    startActivityForResult(i,0);

                    }
                });
                */
                setSupportActionBar(toolbar);

                FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
                fab.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                    Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
                    }
                });
                new AlertDialog.Builder(this)
                    .setTitle(R.string.alert_title)
                    .setItems(R.array.languages,
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialoginterface, int i) {
                            if (i == 1) {
                                setContentView(R.layout.activity_main);

                            } else {
                                setContentView(R.layout.activity_main_fr);
                            }
                            }
                        })
                    .show();




                }
                @Override
                public void onClick(View v) {
                answer1 = (EditText) findViewById(R.id.answer1);
                answer2 = (EditText) findViewById(R.id.answer2);
                answer3 = (EditText) findViewById(R.id.answer3);
                String answer1Value = answer1.getText().toString();
                String answer2Value = answer2.getText().toString();
                String answer3Value = answer3.getText().toString();

                Float answer1ValueFloat = new Float(answer1Value);

                Float answer2ValueFloat = new Float(answer2Value);

                Float answer3ValueFloat = new Float(answer3Value);
                Float average = (answer1ValueFloat+answer2ValueFloat+answer3ValueFloat )/3;
                Intent i = AnswerActivity.newIntent(MainActivity.this,average);
                startActivityForResult(i,0);

                }

                public boolean onCreateOptionsMenu(Menu menu) {
                // Inflate the menu; this adds items to the action bar if it is present.
                getMenuInflater().inflate(R.menu.menu_main, menu);
                return true;
                }

                @Override
                public boolean onOptionsItemSelected(MenuItem item) {
                // Handle action bar item clicks here. The action bar will
                // automatically handle clicks on the Home/Up button, so long
                // as you specify a parent activity in AndroidManifest.xml.
                int id = item.getItemId();

                //noinspection SimplifiableIfStatement
                if (id == R.id.action_settings) {
                    return true;
                }

                return super.onOptionsItemSelected(item);
                }
            }

以下是AnswerActivity.java：

                package gradescalculator.com.calculator.gradescalculator;

            import android.content.Context;
            import android.content.Intent;
            import android.os.Bundle;
            import android.support.v7.app.AppCompatActivity;

            /**
             * Created by aa on 3/6/2016.
             */
            public class AnswerActivity extends AppCompatActivity {
                private static final String CALCULATE_ANSWER="com.calculate.answer";

                protected void onCreate(Bundle saveInstanceState) {
                super.onCreate(saveInstanceState);
                setContentView(R.layout.activity_answer);
                }

                public static Intent newIntent(Context packageContext, Float average) {
                Intent i = new Intent(packageContext, AnswerActivity.class);
                i.putExtra(CALCULATE_ANSWER, average);
                return i;
                }
            }

以下是activity_answer.xml：

                <?xml version="1.0" encoding="utf-8"?>
            <RelativeLayout
                xmlns:android="http://schemas.android.com/apk/res/android"
                xmlns:app="http://schemas.android.com/apk/res-auto"
                xmlns:tools="http://schemas.android.com/tools"
                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"
                app:layout_behavior="@string/appbar_scrolling_view_behavior"
                tools:context="gradescalculator.com.calculator.gradescalculator.MainActivity"
                tools:showIn="@layout/activity_main">

                <TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
                     android:id="@+id/tableLayout1"
                     android:layout_width="fill_parent"
                     android:layout_height="fill_parent">

                <TableRow
                    android:id="@+id/tableRow1"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="5dip">
                    <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/grades_average"/>
                </TableRow>
                <TableRow
                    android:id="@+id/tableRow2"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="5dip">
                    <TextView
                    android:id="@+id/answerGrade1"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/grade1"/>

                </TableRow>
                <TableRow
                    android:id="@+id/tableRow3"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="5dip">
                    <TextView
                    android:id="@+id/answerGrade2"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/grade2"/>

                </TableRow>
                <TableRow
                    android:id="@+id/tableRow4"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="5dip">
                    <TextView
                    android:id="@+id/answerGrade3"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/grade3"/>

                </TableRow>
                <TableRow
                    android:id="@+id/tableRow5"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="5dip">
                    <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/grades_average"/>
                    <TextView
                    android:id="@+id/gradeAverage"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                       />
                </TableRow>
                </TableLayout>
            </RelativeLayout>

以下是activity_main.xml：

                <?xml version="1.0" encoding="utf-8"?>
            <android.support.design.widget.CoordinatorLayout
                xmlns:android="http://schemas.android.com/apk/res/android"
                xmlns:app="http://schemas.android.com/apk/res-auto"
                xmlns:tools="http://schemas.android.com/tools"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:fitsSystemWindows="true"
                tools:context="gradescalculator.com.calculator.gradescalculator.MainActivity">

                <android.support.design.widget.AppBarLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:theme="@style/AppTheme.AppBarOverlay">

                <android.support.v7.widget.Toolbar
                    android:id="@+id/toolbar"
                    android:layout_width="match_parent"
                    android:layout_height="?attr/actionBarSize"
                    android:background="?attr/colorPrimary"
                    app:popupTheme="@style/AppTheme.PopupOverlay"/>

                </android.support.design.widget.AppBarLayout>

                <include layout="@layout/content_main"/>

                <android.support.design.widget.FloatingActionButton
                android:id="@+id/fab"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="bottom|end"
                android:layout_margin="@dimen/fab_margin"
                android:src="@android:drawable/ic_dialog_email"/>

            </android.support.design.widget.CoordinatorLayout>

以下是content_main.xml：

                <?xml version="1.0" encoding="utf-8"?>
            <RelativeLayout
                xmlns:android="http://schemas.android.com/apk/res/android"
                xmlns:app="http://schemas.android.com/apk/res-auto"
                xmlns:tools="http://schemas.android.com/tools"
                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"
                app:layout_behavior="@string/appbar_scrolling_view_behavior"
                tools:context="gradescalculator.com.calculator.gradescalculator.MainActivity"
                tools:showIn="@layout/activity_main">

                <TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
                     android:id="@+id/tableLayout1"
                     android:layout_width="fill_parent"
                     android:layout_height="fill_parent">

                <TableRow
                    android:id="@+id/tableRow1"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="5dip">
                    <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/enter_grades"/>
                </TableRow>
                <TableRow
                    android:id="@+id/tableRow2"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="5dip">
                    <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/grade1"/>
                    <EditText
                    android:id="@+id/answer1"

                    android:layout_height="wrap_content"
                    android:layout_width="wrap_content"

                    />
                </TableRow>
                <TableRow
                    android:id="@+id/tableRow3"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="5dip">
                    <TextView

                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/grade2"/>
                    <EditText
                    android:id="@+id/answer2"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"

                     />
                </TableRow>
                <TableRow
                android:id="@+id/tableRow4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="5dip">
                <TextView

                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/grade3"/>
                <EditText
                    android:id="@+id/answer3"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"

                    />
                </TableRow>
                <TableRow
                    android:id="@+id/tableRow5"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="5dip">
                    <Button android:id="@+id/calculate"
                        android:text="@string/calculate_grade" />

                </TableRow>
                </TableLayout>
            </RelativeLayout>

Answer 1

首先将MainActivity.java中'calculate'的视图类型从“View”更改为“Button”。您需要将计算类型转换为Button视图以将OnClickListener设置为它。基本上，替换

private View calculate;

与

private Button calculate;

和

calculate = findViewById(R.id.calculate);

用，

calculate = (Button) findViewById(R.id.calculate);

Answer 2

Calculate是Button的id，所以你应该在java类中初始化Button而不是view。像这样：

//reload partially page with ajax (only new content between <info> tags)
var HTTP = {};
HTTP._factories = [function () {
        return new XMLHttpRequest();
    }, function () {
        return new ActiveXObject("Msxml2.XMLHTTP");
    }, function () {
        return new ActiveXObject("Microsoft.XMLHTTP");
    }
];
HTTP._factory = null;
HTTP.newRequest = function () {
    if (HTTP._factory != null)
        return HTTP._factory();
    for (var i = 0; i < HTTP._factories.length; i++) {
        try {
            var factory = HTTP._factories[i];
            var request = factory();
            if (request != null) {
                HTTP._factory = factory;
                return request;
            }
        } catch (e) {
            continue;
        }
    }
    HTTP._factory = function () {
        throw new Error("This browser doesn't permit automatic reload of content");
    }
    HTTP._factory();
}
//reloads contents inside of <info> tags every minute 
function reloadInfo() {
    var request = HTTP.newRequest();
    request.onreadystatechange = function () {
        if (request.readyState == 4) {
            if (request.status == 200)
                var infodoc = request.responseText;
            var infodiv = infodoc.substring(infodoc.indexOf('<info>'), infodoc.indexOf('</info>') + 7);
            document.getElementById('info').parentNode.innerHTML = infodiv;
        }
    }
    request.open("GET", window.location);
    request.send(null);
}
window.onload = function () {
    var interval = 60000;
    setInterval("reloadInfo()", interval);
}

Answer 3

 //find your Button  like this instead of view

Button calculate =(Button)findViewById(R.id.calculate);

            //use this below code for trigger button 

             @Override
            public void onClick(View v) {
             switch(v.getId())
              {
                     case R.id.calculate:
                            //write your code at here... it will work
                      break;
              }

            }

Answer 4

删除此

private View calculate;
calculate = findViewById(R.id.calculate);

替换为

private Button calculate;
calculate =(Button) findViewById(R.id.calculate);

android View.OnClickListener不会触发

4 个答案: