Question

我创建了一个欢迎页面（启动器）并包含了一个进度条。在此进度条加载后（几秒钟）将显示下一个活动。这是第一次，当应用程序运行时，几秒后，下一个显示活动。现在，当我按下后退按钮时，正在显示欢迎活动。但是这一次，几秒钟后，它正在调用下一个活动（使用Intent），就像第一次一样。如何解决这个问题？代码是：

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ProgressBar;

public class WelcomeActivity extends AppCompatActivity {
    ProgressBar p;
    private boolean mbActive;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_welcome);
        p = (ProgressBar) findViewById(R.id.progressBar);
        final Thread timerThread = new Thread() {
            @Override
            public void run() {
                mbActive = true;
                try {
                    int waited = 0;
                    while(mbActive && (waited < 1000)) {
                        sleep(200);
                        if(mbActive) {
                            waited += 200;
                            updateProgress(waited);
                        }
                    }
                } catch(InterruptedException e) {
                } finally {
                    onContinue();
                }
            }
        };
        timerThread.start();

    }
    @Override
    public void onDestroy() {
        super.onDestroy();
    }
    public void updateProgress(final int timePassed) {
        if(null != p) {
            final int progress = p.getMax() * timePassed / 100;
            p.setProgress(progress);
        }
    }

    public void onContinue() {
        Intent intd=new Intent(this,MainActivity.class);
        startActivity(intd);
    }


}

Answer 1

您应该使用 setVisibility(View.GONE);/setVisibility(View.INVISIBLE) 。

public void onContinue() 
    {
    p.setVisibility(View.GONE);
    Intent intd=new Intent(this,MainActivity.class);
    startActivity(intd);
    }

<强> FYI

如果您尝试发送，则CalledFromWrongThreadException是一个常见错误从UI线程外部到UI线程的UI事件。

对于你的崩溃案例。阅读 runOnUiThread

Answer 2

试试这个：--- 我改变代码保持进度显示代码在简历

 public class WelcomeActivity extends AppCompatActivity {

    ProgressBar p;
    private boolean mbActive;

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

    public void updateProgress(final int timePassed) {
      if (null != p) {
        final int progress = p.getMax() * timePassed / 100;
        p.setProgress(progress);
      }
    }

    public void onContinue() {
      Intent intd = new Intent(this, MainActivity.class);
      startActivity(intd);
    }

    @Override
    protected void onResume() {
      super.onResume();
      showProgress();
    }

    private void showProgress() {
      p = (ProgressBar) findViewById(R.id.progressBar);
      final Thread timerThread = new Thread() {
        @Override
        public void run() {
          mbActive = true;
          try {
            int waited = 0;
            while (mbActive && (waited < 1000)) {
              sleep(200);
              if (mbActive) {
                waited += 200;
                updateProgress(waited);
              }
            }
          } catch (InterruptedException e) {
          } finally {
            onContinue();
          }
        }
      };
      timerThread.start();
    }

    @Override
    public void onDestroy() {
      super.onDestroy();
    }
  }

Answer 3

关闭进度对话框

public void onContinue() 
{
p.dismiss();
Intent intd=new Intent(this,MainActivity.class);
startActivity(intd);
}

第二次调用活动时，不会停止进度条加载

3 个答案: