Question

我建了一个小进度条。按下按钮时，进度条开始计数，从1到100。我在运行时将按钮文本更改为“正在运行”。但是当我试图将文本更改为“再次？”时在它达到100之后（在while循环结束之后），应用程序突然停止 - 每次。有帮助吗？提前谢谢。

    package com.myfirstapplication.owner.myfirstapplication;

    import android.os.Handler;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.view.View;
    import android.widget.Button;
    import android.widget.ProgressBar;
    import android.widget.TextClock;
    import android.widget.TextView;

    public class MainActivity extends AppCompatActivity {
    ProgressBar pg;
    Button bt;
    int progressStatus = 0;
    TextView tv;
    Handler handler = new Handler();

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

        pg = (ProgressBar) findViewById(R.id.progressBar);
        bt = (Button) findViewById(R.id.btn);
        tv = (TextView) findViewById(R.id.textID);

        bt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                bt.setText("Running.");
                progressStatus = 0;
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        while (progressStatus < 100) {
                            progressStatus++;
                            handler.post(new Runnable() {
                                @Override
                                public void run() {
                                    pg.setProgress(progressStatus);
                                    tv.setText("Progress: " + progressStatus + "/" + pg.getMax());
                                }
                            });
                            try {
                                Thread.sleep(100);
                            } catch (InterruptedException e) {
                                e.printStackTrace();
                            }
                        }

                        bt.setText("Again?");


                    }
                }).start();

            }
        });


    }
}

Answer 1

bt.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            bt.setText("Running.");
            progressStatus = 0;
            new Thread(new Runnable() {
                @Override
                public void run() {
                    while (progressStatus < 100) {
                        progressStatus++;
                        handler.post(new Runnable() {
                            @Override
                            public void run() {
                                pg.setProgress(progressStatus);
                                tv.setText("Progress: " + progressStatus + "/" + pg.getMax());
                            }
                        });
                        try {
                            Thread.sleep(100);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }

                    handler.post(new Runnable() {
                            @Override
                            public void run() {
                                bt.setText("Again?");
                            }
                        });


                }
            }).start();

        }
    });

进度条达到100后，应用程序停止

1 个答案: