java - .setText() 在使用计时器时不适用于 textview

Question

我是编程新手，我正在尝试设计一个简单的数学游戏.. 因为我想要一个方法，它将在 3 秒后将文本设置为 textview，如果单击任何按钮，则必须取消计时器。我试过这个，但它不起作用......任何帮助将不胜感激 抱歉我错误的变量命名，

public class MainActivity extends Activity implements OnClickListener {
Button b1, b2, b3;
ImageView i, i2, i3;
TextView t1, t2, t3;
String s1, s2, s3, s4, s5;
Button bk;
int q, m, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, n[];
Random r1 = new Random();
Random r0 = new Random();
Timer t = new Timer();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    b1 = (Button) findViewById(R.id.button1);
    b2 = (Button) findViewById(R.id.button2);
    b3 = (Button) findViewById(R.id.button3);
    i = (ImageView) findViewById(R.id.imageView1);
    t1 = (TextView) findViewById(R.id.textView1);
    t2 = (TextView) findViewById(R.id.textView2);
    t3 = (TextView) findViewById(R.id.textView3);
    b1.setOnClickListener(this);
    b2.setOnClickListener(this);
    b3.setOnClickListener(this);

    imp();

}

public void imp() {

    t.schedule(new TimerTask() {
        public void run() {
            t3.setText("times up");
            t3.setVisibility(View.VISIBLE);
        }
    }, 3000);

    r2 = r1.nextInt(9) + 1;
    r3 = r1.nextInt(9) + 1;
    r4 = r2 + r3;
    r5 = r2 - r3;
    r6 = r2 * r3;

    n = new int[] { r4, r5, r6 };

    doit();
    while (r9 == r11 || r9 == r13 || r11 == r13) {
        doit();
    }
    s1 = Integer.toString(r2);
    s2 = Integer.toString(r3);
    s3 = Integer.toString(r9);
    s4 = Integer.toString(r11);
    s5 = Integer.toString(r13);
    t1.setText(s1);
    t2.setText(s2);
    b1.setText(s3);
    b2.setText(s4);
    b3.setText(s5);

    int[] images = { R.drawable.plus, R.drawable.minus, R.drawable.multiply };

    Random random = new Random();
    m = images[random.nextInt(images.length)];
    i.setImageResource(m);
    bk.setFocusable(true);
    bk.requestFocus();
    bk.requestFocusFromTouch();
}

public void doit() {
    r9 = 0;
    r11 = 0;
    r13 = 0;
    r8 = r1.nextInt(3) + 0;
    r9 = n[r8];
    r10 = r1.nextInt(3) + 0;
    r11 = n[r10];
    r12 = r1.nextInt(3) + 0;
    r13 = n[r12];
    int[] buttons = { R.id.button1, R.id.button2, R.id.button3 };
    q = buttons[r0.nextInt(buttons.length)];
    bk = (Button) findViewById(q);

}

@Override
public void onClick(View v) {
    switch (v.getId()) {
    case R.id.button1:
        click(r9, b1);
        break;
    case R.id.button2:
        click(r11, b2);
        break;
    case R.id.button3:
        click(r13, b3);
        break;
    }
}
public void click(int k, Button b) {
    if (m == R.drawable.plus && k == r4 || m == R.drawable.minus && k == r5 || m == R.drawable.multiply && k == r6) {
        t.cancel();
        imp();

    } else {
        t3.setText("FINISH");
        t3.setVisibility(View.VISIBLE);
        b.setPressed(true);
        b1.setClickable(false);
        b2.setClickable(false);
        b3.setClickable(false);
        b.requestFocusFromTouch();

    }
  }
}

布局是`

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center_horizontal|center_vertical"
android:orientation="vertical" >

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >

<TextView
android:textSize="30dp"
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="46dp"
android:layout_weight="0.97"
android:editable="false"
android:text="Large Text"
android:gravity="right"
android:textAppearance="?android:attr/textAppearanceLarge" />

<ImageView
android:layout_weight="1"
android:id="@+id/imageView1"
android:layout_width="67dp"
android:layout_height="29dp"
android:src="@drawable/plus" />

<TextView
android:textSize="30dp"
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_weight="1.00"
android:text="Large Text"
android:gravity="left"
android:textAppearance="?android:attr/textAppearanceLarge" />

</LinearLayout>

<LinearLayout
android:id="@+id/pooka"
android:paddingTop="100dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<Button
  android:layout_weight="1"
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
<Button
 android:layout_weight="1"
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />

<Button
 android:layout_weight="1"
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />

</LinearLayout>

<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingTop="50dp"
android:text="Large Text"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textSize="50sp" 
android:visibility="invisible"/>

</LinearLayout>

根据答案进行更改后，现在我遇到了 onclick 问题， 这是我的 logcat 报告

 `04-03 05:11:14.084: E/AndroidRuntime(9317): FATAL EXCEPTION: main
04-03 05:11:14.084: E/AndroidRuntime(9317): java.lang.IllegalStateException: Timer was canceled
04-03 05:11:14.084: E/AndroidRuntime(9317):     at java.util.Timer.scheduleImpl(Timer.java:561)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at java.util.Timer.schedule(Timer.java:459)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at com.example.emo2.MainActivity.imp(MainActivity.java:56)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at com.example.emo2.MainActivity.click(MainActivity.java:146)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at com.example.emo2.MainActivity.onClick(MainActivity.java:134)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at android.view.View.performClick(View.java:4212)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at android.view.View$PerformClick.run(View.java:17476)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at android.os.Handler.handleCallback(Handler.java:800)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at android.os.Handler.dispatchMessage(Handler.java:100)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at android.os.Looper.loop(Looper.java:194)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at android.app.ActivityThread.main(ActivityThread.java:5371)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at java.lang.reflect.Method.invokeNative(Native Method)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at java.lang.reflect.Method.invoke(Method.java:525)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
04-03 05:11:14.084: E/AndroidRuntime(9317):     at dalvik.system.NativeStart.main(Native Method)

` 等待解决方案....

Answer 1

您不能从非主线程更新 UI/ View 元素。 textView 的更新必须在 UI 线程上进行。以下应该有效:

将 run() 方法的内容替换为以下内容:

runOnUiThread(new Runnable() {
    public void run() {
        t3.setText("times up");
        t3.setVisibility(View.VISIBLE);
    } 
});