android按钮不点击,按钮不点击在Android Studio中

你Button点击正常，但最主要的是你没有fact值设置为TextView。

＃。由于您已在onCreate()之外声明Button和TextView，因此无需在onCreate()内再次声明它。

用途：

mfactbutton = (Button) findViewById(R.id.button);

mfacttext = (TextView) findViewById(R.id.textView2);

相反的：

Button mfactbutton = (Button) findViewById(R.id.button);

TextView mfacttext = (TextView) findViewById(R.id.textView2);

＃。在onClick()方法显示在TextViewfact值或显示Toast消息：

// TextView

mfacttext.setText(fact);

// Toast

Toast.makeText(getApplicationContext(), "Fact: " + fact, Toast.LENGTH_SHORT).show();

下面是工作的代码：

public class MainActivity extends AppCompatActivity {

private Button mfactbutton;

private TextView mfacttext;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

mfactbutton = (Button) findViewById(R.id.button);

mfacttext = (TextView) findViewById(R.id.textView2);

// now we need to make out button to click

View.OnClickListener Listener = new View.OnClickListener() {

@Override

public void onClick(View v) {

String[] facts = {

"Ants stretch when they wake up in the morning.",

"Ostriches can run faster than horses.",

"Olympic gold medals are actually made mostly of silver.",

"You are born with 300 bones; by the time you are an adult you will have 206.",

"It takes about 8 minutes for light from the Sun to reach Earth.",

"Some bamboo plants can grow almost a meter in just one day.",

"The state of Florida is bigger than England.",

"Some penguins can leap 2-3 meters out of the water.",

"On average, it takes 66 days to form a new habit.",

"Mammoths still walked the earth when the Great Pyramid was being built." };

String fact = "";

Random randomGenerator = new Random();

int randomNumber = randomGenerator.nextInt(facts.length);

fact = facts[randomNumber] + "";

mfacttext.setText(fact);

Toast.makeText(getApplicationContext(), "Fact: " + fact, Toast.LENGTH_SHORT).show();

}

};

mfactbutton.setOnClickListener(Listener);

}

}

OUTPUT：