我试图显示随机事实,并在每次事实发生变化时更改背景颜色。
我使用MainActivity
上的随机数进行操作,但只要按下按钮生成并显示应用程序崩溃的随机数。
以下是GitHub上项目的链接: https://github.com/ishay1999/FunFacts
这是logCat中显示的错误:
06-09 16:36:27.125 14551-14551/com.howtoevery.funfacts E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.howtoevery.funfacts, PID: 14551
android.content.res.Resources$NotFoundException: String resource ID #0x0
at android.content.res.Resources.getText(Resources.java:275)
at android.widget.TextView.setText(TextView.java:4261)
at com.howtoevery.funfacts.MainActivity$1.onClick(MainActivity.java:56)
at android.view.View.performClick(View.java:4763)
at android.view.View$PerformClick.run(View.java:19821)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5274)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:909)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:704)
这是MainActivity.java
代码:
package com.howtoevery.funfacts;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.widget.TextView;
import java.util.Random;
public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// Creating the random
final Random rand = new Random();
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final TextView factLabel;
final Button showFactButton;
factLabel = (TextView) findViewById(R.id.fact);
final ViewGroup backGround = (RelativeLayout) findViewById(R.id.mainBackground);
showFactButton = (Button) findViewById(R.id.factButton);
View.OnClickListener myListener = new View.OnClickListener() {
int randomNumber;
@Override
public void onClick(View view) {
randomNumber = rand.nextInt(1); // randomNumber will be 0 or 1
switch (randomNumber) {
case 0: { // in case it is 0, show fact number 1 with green color
factLabel.setText(R.string.fact1);
backGround.setBackgroundColor(getResources().getColor(R.color.android_green));
showFactButton.setTextColor(getResources().getColor(R.color.android_green));
} break;
case 1: { // in case it is 1, show fact number 2 with orange color
factLabel.setText(R.string.fact2);
backGround.setBackgroundColor(getResources().getColor(R.color.orangish));
showFactButton.setTextColor(getResources().getColor(R.color.orangish));
} break;
}
factLabel.setText(randomNumber); // show the number generated with randomNumber, ONLY FOR DEBUG PURPOSES
}
};
showFactButton.setOnClickListener(myListener);
}
@Override
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);
}
}
我对应用程序的期望是它会显示不同的事实并改变颜色(现在,对于调试,我希望看到文本更改为生成的随机数并且颜色已更改)
为什么它不像我期望的那样工作?
答案 0 :(得分:3)
问题出在这一行:factLabel.setText(randomNumber);
。您想要设置代表randmNumber
的字符串。使用
factLabel.setText(String.valueOf(randomNumber));
您正在使用的setText
版本会查找ID为您提供的int的字符串。如果找不到,则抛出异常
答案 1 :(得分:0)
选中您要用作R.color.<something>
或R.string.<something>
的所有资源。根据您的例外行数(我认为是MainActivity.java:56),您可以找到您的应用中确切存在的资源,并转到某个文件(colors.xml,strings.xml等)并添加它