Question

我已经在Android上取得了进度条，但它根本不起作用。我究竟做错了什么？我刚刚开始学习android。以下是我的代码。

MainActivity.java -

public class MainActivity extends AppCompatActivity {
    ProgressBar progressBar;
    int mporgress=0;
    EditText time;
    private Handler mHandler = new Handler();
    private static final int PROGRESS = 0x1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
           public void Startbuttononclick(View view){
               Button startbutton=(Button) findViewById(R.id.button);
               startbutton.setOnClickListener(new View.OnClickListener(){
                   @Override
                   public void onClick(View v) {

                       mporgress = Integer.parseInt(time.getText().toString());
                       progressBar.setProgress(mporgress);

                       new Thread(new Runnable() {
                           public void run() {
                               while (mporgress < 100) {
                                   // Update the progress bar
                                   mHandler.post(new Runnable() {
                                       public void run() {
                                           progressBar.setProgress(mporgress);
                                           mporgress = doWork();
                                           try{
                                               Thread.sleep(1000);
                                           }catch (InterruptedException e){}
                                       }
                                   });
                               }
                           }
                       }).start();

                   }
               });
           }
    public void doprogress(View view) {

    }
        public int doWork(){
                  mporgress++;
            return mporgress;
        }
}

activity_main.xml中 -

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.android.progressbar.MainActivity">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Enter the time:"
        android:inputType="number"
        android:id="@+id/editText" />

    <ProgressBar
        style="?android:attr/progressBarStyleLarge"
        android:layout_width="500dp"
        android:layout_height="200dp"
        android:id="@+id/progressBar4"
        android:layout_gravity="center"
        android:scrollbarSize="500dp" />

    <Button
        android:text="START"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/button"
        android:layout_gravity="center"
        android:onClick="Startbuttononclick" />
</LinearLayout>

请看下面的图片 - - https://i.stack.imgur.com/2TBIb.png

注意 - 输入此图像中的时间是带有提示而不是TextView的EditText。

出现但不起作用。

到目前为止，我已完成了这些更改.- https://i.stack.imgur.com/UujpB.png

但进度条仍在不断旋转。

Answer 1

似乎您忘记初始化EditText -time和ProgressBar。在onCreate内启动它：

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

    progressBar =(ProgressBar) findViewById(R.id.progressBar4);
    time = (EditText) findViewById(R.id.editText); //here
}

同样在内部按钮中，点击bar：

progressBar = new ProgressBar(this);
mporgress = Integer.parseInt(time.getText().toString());
    ................
          .............

Android进度条不起作用

1 个答案: