Android Intents OnClickListener仅1种有效

Question

Only Numbers is working, the rest has no action, but there is no errors. When i click on the Numbers Textview it work and go to the other intent, but when i click on any other TextView it doesn't react at all.

All activities are declared in the manifest.

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.example.android.miwok;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Set the content of the activity to use the activity_main.xml layout file
        setContentView(R.layout.activity_main);

        // Find the View that shows the phrases category
        TextView colors = (TextView) findViewById(R.id.colors);

// Set a click listener on that View
        colors.setOnClickListener(new View.OnClickListener() {
            // The code in this method will be executed when the phrases View is clicked on.
            @Override
            public void onClick(View view) {
                Intent colorsIntent = new Intent(MainActivity.this, ColorsActivity.class);
                startActivity(colorsIntent);
            }
        });




        // Set the content of the activity to use the activity_main.xml layout file
        setContentView(R.layout.activity_main);

        // Find the View that shows the phrases category
        TextView family = (TextView) findViewById(R.id.family);

// Set a click listener on that View
        family.setOnClickListener(new View.OnClickListener() {
            // The code in this method will be executed when the phrases View is clicked on.
            @Override
            public void onClick(View view) {
                Intent familyIntent = new Intent(MainActivity.this, FamilyActivity.class);
                startActivity(familyIntent);
            }
        });




        // Set the content of the activity to use the activity_main.xml layout file
        setContentView(R.layout.activity_main);

        // Find the View that shows the phrases category
        TextView phrases = (TextView) findViewById(R.id.phrases);

// Set a click listener on that View
        phrases.setOnClickListener(new View.OnClickListener() {
            // The code in this method will be executed when the phrases View is clicked on.
            @Override
            public void onClick(View view) {
                Intent phrasesIntent = new Intent(MainActivity.this, PhrasesActivity.class);
                startActivity(phrasesIntent);
            }
        });


        // Set the content of the activity to use the activity_main.xml layout file
        setContentView(R.layout.activity_main);

        // Find the View that shows the phrases category
        TextView numbers = (TextView) findViewById(R.id.numbers);

// Set a click listener on that View
        numbers.setOnClickListener(new View.OnClickListener() {
            // The code in this method will be executed when the phrases View is clicked on.
            @Override
            public void onClick(View view) {
                Intent numbersIntent = new Intent(MainActivity.this, NumbersActivity.class);
                startActivity(numbersIntent);
            }
        });



    }


}

Answer 1

U have declared

setContentView(R.layout.activity_main)

too many times. Declare it only once after super.onCreate.

Answer 2

you should use setContentView() just once. keep the first one and remove others and everything should work just fine.

Answer 3

You are calling setContentView() twice. The second time creates a new set of View objects which are different than the ones which you already set OnClickListener s for. The new View , which are the ones actually displayed, do not have any listeners. Remove the second call and you will be good to go.

ps When you have duplicate code, you should create a method rather than simply copy-and-paste. The places where the duplication differs are good candidates for method parameters. In this case, something like this will work well:

private void createOnClickListener(TextView view, Class<Activity> activityClass) {
    view.setOnClickListener(new View.OnClickListener() {
            // The code in this method will be executed when the phrases View is clicked on.
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(MainActivity.this, activityClass);
                startActivity(intent);
            }
        });
}

Now you can create each listener with a single line:

createOnClickListener(colors, ColorsActivity.class);

Answer 4

Remove this line of code It is setting the layout second time which is causing this issue.

// Set the content of the activity to use the activity_main.xml layout file
 setContentView(R.layout.activity_main);